ClickHouse/src/Parsers/ExpressionElementParsers.cpp

2387 lines
68 KiB
C++

#include <cerrno>
#include <cstdlib>
#include <Poco/String.h>
#include <IO/ReadBufferFromMemory.h>
#include <IO/ReadHelpers.h>
#include <Common/typeid_cast.h>
#include <Common/StringUtils/StringUtils.h>
#include <Common/BinStringDecodeHelper.h>
#include <Parsers/DumpASTNode.h>
#include <Parsers/ASTAsterisk.h>
#include <Parsers/ASTCollation.h>
#include <Parsers/ASTColumnsTransformers.h>
#include <Parsers/ASTExpressionList.h>
#include <Parsers/ASTFunction.h>
#include <Parsers/ASTFunctionWithKeyValueArguments.h>
#include <Parsers/ASTIdentifier.h>
#include <Parsers/ASTLiteral.h>
#include <Parsers/ASTOrderByElement.h>
#include <Parsers/ASTInterpolateElement.h>
#include <Parsers/ASTQualifiedAsterisk.h>
#include <Parsers/ASTQueryParameter.h>
#include <Parsers/ASTSelectWithUnionQuery.h>
#include <Parsers/ASTSubquery.h>
#include <Parsers/ASTTTLElement.h>
#include <Parsers/ASTWindowDefinition.h>
#include <Parsers/ASTAssignment.h>
#include <Parsers/ASTColumnsMatcher.h>
#include <Parsers/ASTExplainQuery.h>
#include <Parsers/ASTSetQuery.h>
#include <Parsers/ASTSelectQuery.h>
#include <Parsers/ASTTablesInSelectQuery.h>
#include <Parsers/ExpressionListParsers.h>
#include <Parsers/IAST_fwd.h>
#include <Parsers/ParserSelectWithUnionQuery.h>
#include <Parsers/ParserCase.h>
#include <Parsers/ExpressionElementParsers.h>
#include <Parsers/ParserCreateQuery.h>
#include <Parsers/ParserExplainQuery.h>
#include <Parsers/queryToString.h>
#include <Interpreters/StorageID.h>
namespace DB
{
namespace ErrorCodes
{
extern const int BAD_ARGUMENTS;
extern const int SYNTAX_ERROR;
extern const int LOGICAL_ERROR;
}
/*
* Build an AST with the following structure:
*
* ```
* SelectWithUnionQuery (children 1)
* ExpressionList (children 1)
* SelectQuery (children 2)
* ExpressionList (children 1)
* Asterisk
* TablesInSelectQuery (children 1)
* TablesInSelectQueryElement (children 1)
* TableExpression (children 1)
* Function <...>
* ```
*/
static ASTPtr buildSelectFromTableFunction(const std::shared_ptr<ASTFunction> & ast_function)
{
auto result_select_query = std::make_shared<ASTSelectWithUnionQuery>();
{
auto select_ast = std::make_shared<ASTSelectQuery>();
select_ast->setExpression(ASTSelectQuery::Expression::SELECT, std::make_shared<ASTExpressionList>());
select_ast->select()->children.push_back(std::make_shared<ASTAsterisk>());
auto list_of_selects = std::make_shared<ASTExpressionList>();
list_of_selects->children.push_back(select_ast);
result_select_query->children.push_back(std::move(list_of_selects));
result_select_query->list_of_selects = result_select_query->children.back();
{
auto tables = std::make_shared<ASTTablesInSelectQuery>();
select_ast->setExpression(ASTSelectQuery::Expression::TABLES, tables);
auto tables_elem = std::make_shared<ASTTablesInSelectQueryElement>();
auto table_expr = std::make_shared<ASTTableExpression>();
tables->children.push_back(tables_elem);
tables_elem->table_expression = table_expr;
tables_elem->children.push_back(table_expr);
table_expr->table_function = ast_function;
table_expr->children.push_back(table_expr->table_function);
}
}
return result_select_query;
}
bool ParserSubquery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserSelectWithUnionQuery select;
ParserExplainQuery explain;
if (pos->type != TokenType::OpeningRoundBracket)
return false;
++pos;
ASTPtr result_node = nullptr;
if (ASTPtr select_node; select.parse(pos, select_node, expected))
{
result_node = std::move(select_node);
}
else if (ASTPtr explain_node; explain.parse(pos, explain_node, expected))
{
const auto & explain_query = explain_node->as<const ASTExplainQuery &>();
if (explain_query.getTableFunction() || explain_query.getTableOverride())
throw Exception(ErrorCodes::BAD_ARGUMENTS, "EXPLAIN in a subquery cannot have a table function or table override");
/// Replace subquery `(EXPLAIN <kind> <explain_settings> SELECT ...)`
/// with `(SELECT * FROM viewExplain("<kind>", "<explain_settings>", SELECT ...))`
String kind_str = ASTExplainQuery::toString(explain_query.getKind());
String settings_str;
if (ASTPtr settings_ast = explain_query.getSettings())
{
if (!settings_ast->as<ASTSetQuery>())
throw Exception(ErrorCodes::BAD_ARGUMENTS, "EXPLAIN settings must be a SET query");
settings_str = queryToString(settings_ast);
}
const ASTPtr & explained_ast = explain_query.getExplainedQuery();
if (explained_ast)
{
auto view_explain = makeASTFunction("viewExplain",
std::make_shared<ASTLiteral>(kind_str),
std::make_shared<ASTLiteral>(settings_str),
explained_ast);
result_node = buildSelectFromTableFunction(view_explain);
}
else
{
auto view_explain = makeASTFunction("viewExplain",
std::make_shared<ASTLiteral>(kind_str),
std::make_shared<ASTLiteral>(settings_str));
result_node = buildSelectFromTableFunction(view_explain);
}
}
else
{
return false;
}
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
node = std::make_shared<ASTSubquery>();
node->children.push_back(result_node);
return true;
}
bool ParserIdentifier::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
/// Identifier in backquotes or in double quotes
if (pos->type == TokenType::QuotedIdentifier)
{
ReadBufferFromMemory buf(pos->begin, pos->size());
String s;
if (*pos->begin == '`')
readBackQuotedStringWithSQLStyle(s, buf);
else
readDoubleQuotedStringWithSQLStyle(s, buf);
if (s.empty()) /// Identifiers "empty string" are not allowed.
return false;
node = std::make_shared<ASTIdentifier>(s);
++pos;
return true;
}
else if (pos->type == TokenType::BareWord)
{
node = std::make_shared<ASTIdentifier>(String(pos->begin, pos->end));
++pos;
return true;
}
else if (allow_query_parameter && pos->type == TokenType::OpeningCurlyBrace)
{
++pos;
if (pos->type != TokenType::BareWord)
{
expected.add(pos, "substitution name (identifier)");
return false;
}
String name(pos->begin, pos->end);
++pos;
if (pos->type != TokenType::Colon)
{
expected.add(pos, "colon between name and type");
return false;
}
++pos;
if (pos->type != TokenType::BareWord)
{
expected.add(pos, "substitution type (identifier)");
return false;
}
String type(pos->begin, pos->end);
++pos;
if (type != "Identifier")
{
expected.add(pos, "substitution type (identifier)");
return false;
}
if (pos->type != TokenType::ClosingCurlyBrace)
{
expected.add(pos, "closing curly brace");
return false;
}
++pos;
node = std::make_shared<ASTIdentifier>("", std::make_shared<ASTQueryParameter>(name, type));
return true;
}
return false;
}
bool ParserTableAsStringLiteralIdentifier::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (pos->type != TokenType::StringLiteral)
return false;
ReadBufferFromMemory in(pos->begin, pos->size());
String s;
if (!tryReadQuotedStringInto(s, in))
{
expected.add(pos, "string literal");
return false;
}
if (in.count() != pos->size())
{
expected.add(pos, "string literal");
return false;
}
if (s.empty())
{
expected.add(pos, "non-empty string literal");
return false;
}
node = std::make_shared<ASTTableIdentifier>(s);
++pos;
return true;
}
bool ParserCompoundIdentifier::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ASTPtr id_list;
if (!ParserList(std::make_unique<ParserIdentifier>(allow_query_parameter), std::make_unique<ParserToken>(TokenType::Dot), false)
.parse(pos, id_list, expected))
return false;
std::vector<String> parts;
ASTs params;
const auto & list = id_list->as<ASTExpressionList &>();
for (const auto & child : list.children)
{
parts.emplace_back(getIdentifierName(child));
if (parts.back().empty())
params.push_back(child->as<ASTIdentifier>()->getParam());
}
ParserKeyword s_uuid("UUID");
UUID uuid = UUIDHelpers::Nil;
if (table_name_with_optional_uuid)
{
if (parts.size() > 2)
return false;
if (s_uuid.ignore(pos, expected))
{
ParserStringLiteral uuid_p;
ASTPtr ast_uuid;
if (!uuid_p.parse(pos, ast_uuid, expected))
return false;
uuid = parseFromString<UUID>(ast_uuid->as<ASTLiteral>()->value.get<String>());
}
if (parts.size() == 1) node = std::make_shared<ASTTableIdentifier>(parts[0], std::move(params));
else node = std::make_shared<ASTTableIdentifier>(parts[0], parts[1], std::move(params));
node->as<ASTTableIdentifier>()->uuid = uuid;
}
else
node = std::make_shared<ASTIdentifier>(std::move(parts), false, std::move(params));
return true;
}
ASTPtr createFunctionCast(const ASTPtr & expr_ast, const ASTPtr & type_ast)
{
/// Convert to canonical representation in functional form: CAST(expr, 'type')
auto type_literal = std::make_shared<ASTLiteral>(queryToString(type_ast));
return makeASTFunction("CAST", expr_ast, std::move(type_literal));
}
bool ParserFilterClause::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
assert(node);
ASTFunction & function = dynamic_cast<ASTFunction &>(*node);
ParserToken parser_opening_bracket(TokenType::OpeningRoundBracket);
if (!parser_opening_bracket.ignore(pos, expected))
{
return false;
}
ParserKeyword parser_where("WHERE");
if (!parser_where.ignore(pos, expected))
{
return false;
}
ParserExpressionList parser_condition(false);
ASTPtr condition;
if (!parser_condition.parse(pos, condition, expected) || condition->children.size() != 1)
{
return false;
}
ParserToken parser_closing_bracket(TokenType::ClosingRoundBracket);
if (!parser_closing_bracket.ignore(pos, expected))
{
return false;
}
function.name += "If";
function.arguments->children.push_back(condition->children[0]);
return true;
}
bool ParserWindowReference::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
assert(node);
ASTFunction & function = dynamic_cast<ASTFunction &>(*node);
// Variant 1:
// function_name ( * ) OVER window_name
if (pos->type != TokenType::OpeningRoundBracket)
{
ASTPtr window_name_ast;
ParserIdentifier window_name_parser;
if (window_name_parser.parse(pos, window_name_ast, expected))
{
function.window_name = getIdentifierName(window_name_ast);
return true;
}
else
{
return false;
}
}
// Variant 2:
// function_name ( * ) OVER ( window_definition )
ParserWindowDefinition parser_definition;
return parser_definition.parse(pos, function.window_definition, expected);
}
static bool tryParseFrameDefinition(ASTWindowDefinition * node, IParser::Pos & pos,
Expected & expected)
{
ParserKeyword keyword_rows("ROWS");
ParserKeyword keyword_groups("GROUPS");
ParserKeyword keyword_range("RANGE");
node->frame_is_default = false;
if (keyword_rows.ignore(pos, expected))
{
node->frame_type = WindowFrame::FrameType::ROWS;
}
else if (keyword_groups.ignore(pos, expected))
{
node->frame_type = WindowFrame::FrameType::GROUPS;
}
else if (keyword_range.ignore(pos, expected))
{
node->frame_type = WindowFrame::FrameType::RANGE;
}
else
{
/* No frame clause. */
node->frame_is_default = true;
return true;
}
ParserKeyword keyword_between("BETWEEN");
ParserKeyword keyword_unbounded("UNBOUNDED");
ParserKeyword keyword_preceding("PRECEDING");
ParserKeyword keyword_following("FOLLOWING");
ParserKeyword keyword_and("AND");
ParserKeyword keyword_current_row("CURRENT ROW");
// There are two variants of grammar for the frame:
// 1) ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
// 2) ROWS UNBOUNDED PRECEDING
// When the frame end is not specified (2), it defaults to CURRENT ROW.
const bool has_frame_end = keyword_between.ignore(pos, expected);
if (keyword_current_row.ignore(pos, expected))
{
node->frame_begin_type = WindowFrame::BoundaryType::Current;
}
else
{
ParserExpression parser_expression;
if (keyword_unbounded.ignore(pos, expected))
{
node->frame_begin_type = WindowFrame::BoundaryType::Unbounded;
}
else if (parser_expression.parse(pos, node->frame_begin_offset, expected))
{
// We will evaluate the expression for offset expression later.
node->frame_begin_type = WindowFrame::BoundaryType::Offset;
}
else
{
return false;
}
if (keyword_preceding.ignore(pos, expected))
{
node->frame_begin_preceding = true;
}
else if (keyword_following.ignore(pos, expected))
{
node->frame_begin_preceding = false;
if (node->frame_begin_type == WindowFrame::BoundaryType::Unbounded)
{
throw Exception(ErrorCodes::BAD_ARGUMENTS,
"Frame start cannot be UNBOUNDED FOLLOWING");
}
}
else
{
return false;
}
}
if (has_frame_end)
{
if (!keyword_and.ignore(pos, expected))
{
return false;
}
if (keyword_current_row.ignore(pos, expected))
{
node->frame_end_type = WindowFrame::BoundaryType::Current;
}
else
{
ParserExpression parser_expression;
if (keyword_unbounded.ignore(pos, expected))
{
node->frame_end_type = WindowFrame::BoundaryType::Unbounded;
}
else if (parser_expression.parse(pos, node->frame_end_offset, expected))
{
// We will evaluate the expression for offset expression later.
node->frame_end_type = WindowFrame::BoundaryType::Offset;
}
else
{
return false;
}
if (keyword_preceding.ignore(pos, expected))
{
node->frame_end_preceding = true;
if (node->frame_end_type == WindowFrame::BoundaryType::Unbounded)
{
throw Exception(ErrorCodes::BAD_ARGUMENTS,
"Frame end cannot be UNBOUNDED PRECEDING");
}
}
else if (keyword_following.ignore(pos, expected))
{
// Positive offset or UNBOUNDED FOLLOWING.
node->frame_end_preceding = false;
}
else
{
return false;
}
}
}
return true;
}
// All except parent window name.
static bool parseWindowDefinitionParts(IParser::Pos & pos,
ASTWindowDefinition & node, Expected & expected)
{
ParserKeyword keyword_partition_by("PARTITION BY");
ParserNotEmptyExpressionList columns_partition_by(
false /* we don't allow declaring aliases here*/);
ParserKeyword keyword_order_by("ORDER BY");
ParserOrderByExpressionList columns_order_by;
if (keyword_partition_by.ignore(pos, expected))
{
ASTPtr partition_by_ast;
if (columns_partition_by.parse(pos, partition_by_ast, expected))
{
node.children.push_back(partition_by_ast);
node.partition_by = partition_by_ast;
}
else
{
return false;
}
}
if (keyword_order_by.ignore(pos, expected))
{
ASTPtr order_by_ast;
if (columns_order_by.parse(pos, order_by_ast, expected))
{
node.children.push_back(order_by_ast);
node.order_by = order_by_ast;
}
else
{
return false;
}
}
return tryParseFrameDefinition(&node, pos, expected);
}
bool ParserWindowDefinition::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
auto result = std::make_shared<ASTWindowDefinition>();
ParserToken parser_openging_bracket(TokenType::OpeningRoundBracket);
if (!parser_openging_bracket.ignore(pos, expected))
{
return false;
}
// We can have a parent window name specified before all other things. No
// easy way to distinguish identifier from keywords, so just try to parse it
// both ways.
if (parseWindowDefinitionParts(pos, *result, expected))
{
// Successfully parsed without parent window specifier. It can be empty,
// so check that it is followed by the closing bracket.
ParserToken parser_closing_bracket(TokenType::ClosingRoundBracket);
if (parser_closing_bracket.ignore(pos, expected))
{
node = result;
return true;
}
}
// Try to parse with parent window specifier.
ParserIdentifier parser_parent_window;
ASTPtr window_name_identifier;
if (!parser_parent_window.parse(pos, window_name_identifier, expected))
{
return false;
}
result->parent_window_name = window_name_identifier->as<const ASTIdentifier &>().name();
if (!parseWindowDefinitionParts(pos, *result, expected))
{
return false;
}
ParserToken parser_closing_bracket(TokenType::ClosingRoundBracket);
if (!parser_closing_bracket.ignore(pos, expected))
{
return false;
}
node = result;
return true;
}
bool ParserWindowList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
auto result = std::make_shared<ASTExpressionList>();
for (;;)
{
auto elem = std::make_shared<ASTWindowListElement>();
ParserIdentifier parser_window_name;
ASTPtr window_name_identifier;
if (!parser_window_name.parse(pos, window_name_identifier, expected))
{
return false;
}
elem->name = getIdentifierName(window_name_identifier);
ParserKeyword keyword_as("AS");
if (!keyword_as.ignore(pos, expected))
{
return false;
}
ParserWindowDefinition parser_window_definition;
if (!parser_window_definition.parse(pos, elem->definition, expected))
{
return false;
}
result->children.push_back(elem);
// If the list countinues, there should be a comma.
ParserToken parser_comma(TokenType::Comma);
if (!parser_comma.ignore(pos))
{
break;
}
}
node = result;
return true;
}
bool ParserCodecDeclarationList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
return ParserList(std::make_unique<ParserIdentifierWithOptionalParameters>(),
std::make_unique<ParserToken>(TokenType::Comma), false).parse(pos, node, expected);
}
bool ParserCodec::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserCodecDeclarationList codecs;
ASTPtr expr_list_args;
if (pos->type != TokenType::OpeningRoundBracket)
return false;
++pos;
if (!codecs.parse(pos, expr_list_args, expected))
return false;
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
auto function_node = std::make_shared<ASTFunction>();
function_node->name = "CODEC";
function_node->arguments = expr_list_args;
function_node->children.push_back(function_node->arguments);
node = function_node;
return true;
}
bool ParserStatisticType::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserList stat_type_parser(std::make_unique<ParserIdentifierWithOptionalParameters>(),
std::make_unique<ParserToken>(TokenType::Comma), false);
if (pos->type != TokenType::OpeningRoundBracket)
return false;
ASTPtr stat_type;
++pos;
if (!stat_type_parser.parse(pos, stat_type, expected))
return false;
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
auto function_node = std::make_shared<ASTFunction>();
function_node->name = "STATISTIC";
function_node->arguments = stat_type;
function_node->children.push_back(function_node->arguments);
node = function_node;
return true;
}
bool ParserCollation::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ASTPtr collation;
if (!ParserIdentifier(true).parse(pos, collation, expected))
return false;
// check the collation name is valid
const String name = getIdentifierName(collation);
bool valid_collation = name == "binary" ||
endsWith(name, "_bin") ||
endsWith(name, "_ci") ||
endsWith(name, "_cs") ||
endsWith(name, "_ks");
if (!valid_collation)
return false;
auto collation_node = std::make_shared<ASTCollation>();
collation_node->collation = collation;
node = collation_node;
return true;
}
template <TokenType ...tokens>
static bool isOneOf(TokenType token)
{
return ((token == tokens) || ...);
}
bool ParserCastOperator::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
using enum TokenType;
/// Parse numbers (including decimals), strings, arrays and tuples of them.
const char * data_begin = pos->begin;
const char * data_end = pos->end;
bool is_string_literal = pos->type == StringLiteral;
if (pos->type == Minus)
{
++pos;
if (pos->type != Number)
return false;
data_end = pos->end;
++pos;
}
else if (pos->type == Number || is_string_literal)
{
++pos;
}
else if (isOneOf<OpeningSquareBracket, OpeningRoundBracket>(pos->type))
{
TokenType last_token = OpeningSquareBracket;
std::vector<TokenType> stack;
while (pos.isValid())
{
if (isOneOf<OpeningSquareBracket, OpeningRoundBracket>(pos->type))
{
stack.push_back(pos->type);
if (!isOneOf<OpeningSquareBracket, OpeningRoundBracket, Comma>(last_token))
return false;
}
else if (pos->type == ClosingSquareBracket)
{
if (isOneOf<Comma, OpeningRoundBracket, Minus>(last_token))
return false;
if (stack.empty() || stack.back() != OpeningSquareBracket)
return false;
stack.pop_back();
}
else if (pos->type == ClosingRoundBracket)
{
if (isOneOf<Comma, OpeningSquareBracket, Minus>(last_token))
return false;
if (stack.empty() || stack.back() != OpeningRoundBracket)
return false;
stack.pop_back();
}
else if (pos->type == Comma)
{
if (isOneOf<OpeningSquareBracket, OpeningRoundBracket, Comma, Minus>(last_token))
return false;
if (stack.empty())
break;
}
else if (pos->type == Number)
{
if (!isOneOf<OpeningSquareBracket, OpeningRoundBracket, Comma, Minus>(last_token))
return false;
}
else if (isOneOf<StringLiteral, Minus>(pos->type))
{
if (!isOneOf<OpeningSquareBracket, OpeningRoundBracket, Comma>(last_token))
return false;
}
else
{
break;
}
/// Update data_end on every iteration to avoid appearances of extra trailing
/// whitespaces into data. Whitespaces are skipped at operator '++' of Pos.
data_end = pos->end;
last_token = pos->type;
++pos;
}
if (!stack.empty())
return false;
}
else
return false;
ASTPtr type_ast;
if (ParserToken(DoubleColon).ignore(pos, expected)
&& ParserDataType().parse(pos, type_ast, expected))
{
String s;
size_t data_size = data_end - data_begin;
if (is_string_literal)
{
ReadBufferFromMemory buf(data_begin, data_size);
readQuotedStringWithSQLStyle(s, buf);
assert(buf.count() == data_size);
}
else
s = String(data_begin, data_size);
auto literal = std::make_shared<ASTLiteral>(std::move(s));
node = createFunctionCast(literal, type_ast);
return true;
}
return false;
}
bool ParserNull::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserKeyword nested_parser("NULL");
if (nested_parser.parse(pos, node, expected))
{
node = std::make_shared<ASTLiteral>(Null());
return true;
}
else
return false;
}
bool ParserBool::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (ParserKeyword("true").parse(pos, node, expected))
{
node = std::make_shared<ASTLiteral>(true);
return true;
}
else if (ParserKeyword("false").parse(pos, node, expected))
{
node = std::make_shared<ASTLiteral>(false);
return true;
}
else
return false;
}
static bool parseNumber(char * buffer, size_t size, bool negative, int base, Field & res)
{
errno = 0; /// Functions strto* don't clear errno.
char * pos_integer = buffer;
UInt64 uint_value = std::strtoull(buffer, &pos_integer, base);
if (pos_integer == buffer + size && errno != ERANGE && (!negative || uint_value <= (1ULL << 63)))
{
/// -0 should be still parsed as UInt instead of Int,
/// because otherwise it is not preserved during formatting-parsing roundtrip
/// (the signedness is lost during formatting)
if (negative && uint_value != 0)
res = static_cast<Int64>(-uint_value);
else
res = uint_value;
return true;
}
return false;
}
bool ParserNumber::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
Pos literal_begin = pos;
bool negative = false;
if (pos->type == TokenType::Minus)
{
++pos;
negative = true;
}
else if (pos->type == TokenType::Plus) /// Leading plus is simply ignored.
++pos;
Field res;
if (!pos.isValid())
return false;
auto try_read_float = [&](const char * it, const char * end)
{
std::string buf(it, end); /// Copying is needed to ensure the string is 0-terminated.
char * str_end;
errno = 0; /// Functions strto* don't clear errno.
/// The usage of strtod is needed, because we parse hex floating point literals as well.
Float64 float_value = std::strtod(buf.c_str(), &str_end);
if (str_end == buf.c_str() + buf.size() && errno != ERANGE)
{
if (float_value < 0)
throw Exception(ErrorCodes::LOGICAL_ERROR,
"Logical error: token number cannot begin with minus, "
"but parsed float number is less than zero.");
if (negative)
float_value = -float_value;
res = float_value;
auto literal = std::make_shared<ASTLiteral>(res);
literal->begin = literal_begin;
literal->end = ++pos;
node = literal;
return true;
}
expected.add(pos, "number");
return false;
};
/// NaN and Inf
if (pos->type == TokenType::BareWord)
{
return try_read_float(pos->begin, pos->end);
}
if (pos->type != TokenType::Number)
{
expected.add(pos, "number");
return false;
}
/** Maximum length of number. 319 symbols is enough to write maximum double in decimal form.
* Copy is needed to use strto* functions, which require 0-terminated string.
*/
static constexpr size_t MAX_LENGTH_OF_NUMBER = 319;
char buf[MAX_LENGTH_OF_NUMBER + 1];
size_t buf_size = 0;
for (const auto * it = pos->begin; it != pos->end; ++it)
{
if (*it != '_')
{
buf[buf_size] = *it;
++buf_size;
}
if (unlikely(buf_size > MAX_LENGTH_OF_NUMBER))
{
expected.add(pos, "number");
return false;
}
}
size_t size = buf_size;
buf[size] = 0;
char * start_pos = buf;
if (*start_pos == '0')
{
++start_pos;
--size;
/// binary
if (*start_pos == 'b')
{
++start_pos;
--size;
if (parseNumber(start_pos, size, negative, 2, res))
{
auto literal = std::make_shared<ASTLiteral>(res);
literal->begin = literal_begin;
literal->end = ++pos;
node = literal;
return true;
}
else
return false;
}
/// hexadecimal
if (*start_pos == 'x' || *start_pos == 'X')
{
++start_pos;
--size;
if (parseNumber(start_pos, size, negative, 16, res))
{
auto literal = std::make_shared<ASTLiteral>(res);
literal->begin = literal_begin;
literal->end = ++pos;
node = literal;
return true;
}
}
else
{
/// possible leading zeroes in integer
while (*start_pos == '0')
{
++start_pos;
--size;
}
if (parseNumber(start_pos, size, negative, 10, res))
{
auto literal = std::make_shared<ASTLiteral>(res);
literal->begin = literal_begin;
literal->end = ++pos;
node = literal;
return true;
}
}
}
else if (parseNumber(start_pos, size, negative, 10, res))
{
auto literal = std::make_shared<ASTLiteral>(res);
literal->begin = literal_begin;
literal->end = ++pos;
node = literal;
return true;
}
return try_read_float(buf, buf + buf_size);
}
bool ParserUnsignedInteger::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
Field res;
if (!pos.isValid())
return false;
UInt64 x = 0;
ReadBufferFromMemory in(pos->begin, pos->size());
if (!tryReadIntText(x, in) || in.count() != pos->size())
{
expected.add(pos, "unsigned integer");
return false;
}
res = x;
auto literal = std::make_shared<ASTLiteral>(res);
literal->begin = pos;
literal->end = ++pos;
node = literal;
return true;
}
inline static bool makeStringLiteral(IParser::Pos & pos, ASTPtr & node, String str)
{
auto literal = std::make_shared<ASTLiteral>(str);
literal->begin = pos;
literal->end = ++pos;
node = literal;
return true;
}
inline static bool makeHexOrBinStringLiteral(IParser::Pos & pos, ASTPtr & node, bool hex, size_t word_size)
{
const char * str_begin = pos->begin + 2;
const char * str_end = pos->end - 1;
if (str_begin == str_end)
return makeStringLiteral(pos, node, "");
PODArray<UInt8> res;
res.resize((pos->size() + word_size) / word_size + 1);
char * res_begin = reinterpret_cast<char *>(res.data());
char * res_pos = res_begin;
if (hex)
{
hexStringDecode(str_begin, str_end, res_pos);
}
else
{
binStringDecode(str_begin, str_end, res_pos);
}
return makeStringLiteral(pos, node, String(reinterpret_cast<char *>(res.data()), (res_pos - res_begin - 1)));
}
bool ParserStringLiteral::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (pos->type != TokenType::StringLiteral && pos->type != TokenType::HereDoc)
return false;
String s;
if (pos->type == TokenType::StringLiteral)
{
if (*pos->begin == 'x' || *pos->begin == 'X')
{
constexpr size_t word_size = 2;
return makeHexOrBinStringLiteral(pos, node, true, word_size);
}
if (*pos->begin == 'b' || *pos->begin == 'B')
{
constexpr size_t word_size = 8;
return makeHexOrBinStringLiteral(pos, node, false, word_size);
}
ReadBufferFromMemory in(pos->begin, pos->size());
try
{
readQuotedStringWithSQLStyle(s, in);
}
catch (const Exception &)
{
expected.add(pos, "string literal");
return false;
}
if (in.count() != pos->size())
{
expected.add(pos, "string literal");
return false;
}
}
else if (pos->type == TokenType::HereDoc)
{
std::string_view here_doc(pos->begin, pos->size());
size_t heredoc_size = here_doc.find('$', 1) + 1;
assert(heredoc_size != std::string_view::npos);
s = String(pos->begin + heredoc_size, pos->size() - heredoc_size * 2);
}
return makeStringLiteral(pos, node, s);
}
template <typename Collection>
struct CollectionOfLiteralsLayer
{
explicit CollectionOfLiteralsLayer(IParser::Pos & pos) : literal_begin(pos)
{
++pos;
}
IParser::Pos literal_begin;
Collection arr;
};
template <typename Collection>
bool ParserCollectionOfLiterals<Collection>::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (pos->type != opening_bracket)
return false;
std::vector<CollectionOfLiteralsLayer<Collection>> layers;
layers.emplace_back(pos);
pos.increaseDepth();
ParserLiteral literal_p;
while (pos.isValid())
{
if (!layers.back().arr.empty())
{
if (pos->type == closing_bracket)
{
std::shared_ptr<ASTLiteral> literal;
/// Parse one-element tuples (e.g. (1)) later as single values for backward compatibility.
if (std::is_same_v<Collection, Tuple> && layers.back().arr.size() == 1)
return false;
literal = std::make_shared<ASTLiteral>(std::move(layers.back().arr));
literal->begin = layers.back().literal_begin;
literal->end = ++pos;
layers.pop_back();
pos.decreaseDepth();
if (layers.empty())
{
node = literal;
return true;
}
layers.back().arr.push_back(literal->value);
continue;
}
else if (pos->type == TokenType::Comma)
{
++pos;
}
else if (pos->type == TokenType::Colon && std::is_same_v<Collection, Map> && layers.back().arr.size() % 2 == 1)
{
++pos;
}
else
{
expected.add(pos, "comma or closing bracket");
return false;
}
}
ASTPtr literal_node;
if (literal_p.parse(pos, literal_node, expected))
{
layers.back().arr.push_back(literal_node->as<ASTLiteral &>().value);
}
else if (pos->type == opening_bracket)
{
layers.emplace_back(pos);
pos.increaseDepth();
}
else
return false;
}
expected.add(pos, getTokenName(closing_bracket));
return false;
}
template bool ParserCollectionOfLiterals<Array>::parseImpl(Pos & pos, ASTPtr & node, Expected & expected);
template bool ParserCollectionOfLiterals<Tuple>::parseImpl(Pos & pos, ASTPtr & node, Expected & expected);
namespace
{
class ICollection;
using Collections = std::vector<std::unique_ptr<ICollection>>;
class ICollection
{
public:
virtual ~ICollection() = default;
virtual bool parse(IParser::Pos & pos, Collections & collections, ASTPtr & node, Expected & expected, bool allow_map) = 0;
};
template <class Container, TokenType end_token>
class CommonCollection : public ICollection
{
public:
explicit CommonCollection(const IParser::Pos & pos) : begin(pos) {}
bool parse(IParser::Pos & pos, Collections & collections, ASTPtr & node, Expected & expected, bool allow_map) override;
private:
Container container;
IParser::Pos begin;
};
class MapCollection : public ICollection
{
public:
explicit MapCollection(const IParser::Pos & pos) : begin(pos) {}
bool parse(IParser::Pos & pos, Collections & collections, ASTPtr & node, Expected & expected, bool allow_map) override;
private:
Map container;
IParser::Pos begin;
};
bool parseAllCollectionsStart(IParser::Pos & pos, Collections & collections, Expected & /*expected*/, bool allow_map)
{
if (allow_map && pos->type == TokenType::OpeningCurlyBrace)
collections.push_back(std::make_unique<MapCollection>(pos));
else if (pos->type == TokenType::OpeningRoundBracket)
collections.push_back(std::make_unique<CommonCollection<Tuple, TokenType::ClosingRoundBracket>>(pos));
else if (pos->type == TokenType::OpeningSquareBracket)
collections.push_back(std::make_unique<CommonCollection<Array, TokenType::ClosingSquareBracket>>(pos));
else
return false;
++pos;
return true;
}
template <class Container, TokenType end_token>
bool CommonCollection<Container, end_token>::parse(IParser::Pos & pos, Collections & collections, ASTPtr & node, Expected & expected, bool allow_map)
{
if (node)
{
container.push_back(std::move(node->as<ASTLiteral &>().value));
node.reset();
}
ASTPtr literal;
ParserLiteral literal_p;
ParserToken comma_p(TokenType::Comma);
ParserToken end_p(end_token);
while (true)
{
if (end_p.ignore(pos, expected))
{
auto result = std::make_shared<ASTLiteral>(std::move(container));
result->begin = begin;
result->end = pos;
node = std::move(result);
break;
}
if (!container.empty() && !comma_p.ignore(pos, expected))
return false;
if (literal_p.parse(pos, literal, expected))
container.push_back(std::move(literal->as<ASTLiteral &>().value));
else
return parseAllCollectionsStart(pos, collections, expected, allow_map);
}
return true;
}
bool MapCollection::parse(IParser::Pos & pos, Collections & collections, ASTPtr & node, Expected & expected, bool allow_map)
{
if (node)
{
container.push_back(std::move(node->as<ASTLiteral &>().value));
node.reset();
}
ASTPtr literal;
ParserLiteral literal_p;
ParserToken comma_p(TokenType::Comma);
ParserToken colon_p(TokenType::Colon);
ParserToken end_p(TokenType::ClosingCurlyBrace);
while (true)
{
if (end_p.ignore(pos, expected))
{
auto result = std::make_shared<ASTLiteral>(std::move(container));
result->begin = begin;
result->end = pos;
node = std::move(result);
break;
}
if (!container.empty() && !comma_p.ignore(pos, expected))
return false;
if (!literal_p.parse(pos, literal, expected))
return false;
if (!colon_p.parse(pos, literal, expected))
return false;
container.push_back(std::move(literal->as<ASTLiteral &>().value));
if (literal_p.parse(pos, literal, expected))
container.push_back(std::move(literal->as<ASTLiteral &>().value));
else
return parseAllCollectionsStart(pos, collections, expected, allow_map);
}
return true;
}
}
bool ParserAllCollectionsOfLiterals::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
Collections collections;
if (!parseAllCollectionsStart(pos, collections, expected, allow_map))
return false;
while (!collections.empty())
{
if (!collections.back()->parse(pos, collections, node, expected, allow_map))
return false;
if (node)
collections.pop_back();
}
return true;
}
bool ParserLiteral::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserNull null_p;
ParserNumber num_p;
ParserBool bool_p;
ParserStringLiteral str_p;
if (null_p.parse(pos, node, expected))
return true;
if (num_p.parse(pos, node, expected))
return true;
if (bool_p.parse(pos, node, expected))
return true;
if (str_p.parse(pos, node, expected))
return true;
return false;
}
const char * ParserAlias::restricted_keywords[] =
{
"ALL",
"ANTI",
"ANY",
"ARRAY",
"ASOF",
"BETWEEN",
"CROSS",
"FINAL",
"FORMAT",
"FROM",
"FULL",
"GLOBAL",
"GROUP",
"HAVING",
"ILIKE",
"INNER",
"INTO",
"JOIN",
"LEFT",
"LIKE",
"LIMIT",
"NOT",
"OFFSET",
"ON",
"ONLY", /// YQL's synonym for ANTI. Note: YQL is the name of one of proprietary languages, completely unrelated to ClickHouse.
"ORDER",
"PREWHERE",
"RIGHT",
"SAMPLE",
"SEMI",
"SETTINGS",
"UNION",
"USING",
"WHERE",
"WINDOW",
"WITH",
"INTERSECT",
"EXCEPT",
"ELSE",
nullptr
};
bool ParserAlias::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserKeyword s_as("AS");
ParserIdentifier id_p;
bool has_as_word = s_as.ignore(pos, expected);
if (!allow_alias_without_as_keyword && !has_as_word)
return false;
bool is_quoted = pos->type == TokenType::QuotedIdentifier;
if (!id_p.parse(pos, node, expected))
return false;
if (!has_as_word && !is_quoted)
{
/** In this case, the alias can not match the keyword -
* so that in the query "SELECT x FROM t", the word FROM was not considered an alias,
* and in the query "SELECT x FR FROM t", the word FR was considered an alias.
*/
const String name = getIdentifierName(node);
for (const char ** keyword = restricted_keywords; *keyword != nullptr; ++keyword)
if (0 == strcasecmp(name.data(), *keyword))
return false;
}
return true;
}
bool ParserColumnsTransformers::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserKeyword apply("APPLY");
ParserKeyword except("EXCEPT");
ParserKeyword replace("REPLACE");
ParserKeyword as("AS");
ParserKeyword strict("STRICT");
if (allowed_transformers.isSet(ColumnTransformer::APPLY) && apply.ignore(pos, expected))
{
bool with_open_round_bracket = false;
if (pos->type == TokenType::OpeningRoundBracket)
{
++pos;
with_open_round_bracket = true;
}
ASTPtr lambda;
String lambda_arg;
ASTPtr func_name;
ASTPtr expr_list_args;
auto opos = pos;
if (ParserExpression().parse(pos, lambda, expected))
{
if (auto * func = lambda->as<ASTFunction>(); func && func->name == "lambda")
{
if (func->arguments->children.size() != 2)
throw Exception(ErrorCodes::SYNTAX_ERROR, "lambda requires two arguments");
const auto * lambda_args_tuple = func->arguments->children.at(0)->as<ASTFunction>();
if (!lambda_args_tuple || lambda_args_tuple->name != "tuple")
throw Exception(ErrorCodes::SYNTAX_ERROR, "First argument of lambda must be a tuple");
const ASTs & lambda_arg_asts = lambda_args_tuple->arguments->children;
if (lambda_arg_asts.size() != 1)
throw Exception(ErrorCodes::SYNTAX_ERROR, "APPLY column transformer can only accept lambda with one argument");
if (auto opt_arg_name = tryGetIdentifierName(lambda_arg_asts[0]); opt_arg_name)
lambda_arg = *opt_arg_name;
else
throw Exception(ErrorCodes::SYNTAX_ERROR, "lambda argument declarations must be identifiers");
func->is_lambda_function = true;
}
else
{
lambda = nullptr;
pos = opos;
}
}
if (!lambda)
{
if (!ParserIdentifier().parse(pos, func_name, expected))
return false;
if (pos->type == TokenType::OpeningRoundBracket)
{
++pos;
if (!ParserExpressionList(false).parse(pos, expr_list_args, expected))
return false;
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
}
}
String column_name_prefix;
if (with_open_round_bracket && pos->type == TokenType::Comma)
{
++pos;
ParserStringLiteral parser_string_literal;
ASTPtr ast_prefix_name;
if (!parser_string_literal.parse(pos, ast_prefix_name, expected))
return false;
column_name_prefix = ast_prefix_name->as<ASTLiteral &>().value.get<const String &>();
}
if (with_open_round_bracket)
{
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
}
auto res = std::make_shared<ASTColumnsApplyTransformer>();
if (lambda)
{
res->lambda = lambda;
res->lambda_arg = lambda_arg;
}
else
{
res->func_name = getIdentifierName(func_name);
res->parameters = expr_list_args;
}
res->column_name_prefix = column_name_prefix;
node = std::move(res);
return true;
}
else if (allowed_transformers.isSet(ColumnTransformer::EXCEPT) && except.ignore(pos, expected))
{
if (strict.ignore(pos, expected))
is_strict = true;
ASTs identifiers;
ASTPtr regex_node;
ParserStringLiteral regex;
auto parse_id = [&identifiers, &pos, &expected]
{
ASTPtr identifier;
if (!ParserIdentifier(true).parse(pos, identifier, expected))
return false;
identifiers.emplace_back(std::move(identifier));
return true;
};
if (pos->type == TokenType::OpeningRoundBracket)
{
// support one or more parameter
++pos;
if (!ParserList::parseUtil(pos, expected, parse_id, false) && !regex.parse(pos, regex_node, expected))
return false;
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
}
else
{
// only one parameter
if (!parse_id() && !regex.parse(pos, regex_node, expected))
return false;
}
auto res = std::make_shared<ASTColumnsExceptTransformer>();
if (regex_node)
res->setPattern(regex_node->as<ASTLiteral &>().value.get<String>());
else
res->children = std::move(identifiers);
res->is_strict = is_strict;
node = std::move(res);
return true;
}
else if (allowed_transformers.isSet(ColumnTransformer::REPLACE) && replace.ignore(pos, expected))
{
if (strict.ignore(pos, expected))
is_strict = true;
ASTs replacements;
ParserExpression element_p;
ParserIdentifier ident_p;
auto parse_id = [&]
{
ASTPtr expr;
if (!element_p.parse(pos, expr, expected))
return false;
if (!as.ignore(pos, expected))
return false;
ASTPtr ident;
if (!ident_p.parse(pos, ident, expected))
return false;
auto replacement = std::make_shared<ASTColumnsReplaceTransformer::Replacement>();
replacement->name = getIdentifierName(ident);
replacement->children.push_back(std::move(expr));
replacements.emplace_back(std::move(replacement));
return true;
};
if (pos->type == TokenType::OpeningRoundBracket)
{
++pos;
if (!ParserList::parseUtil(pos, expected, parse_id, false))
return false;
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
}
else
{
// only one parameter
if (!parse_id())
return false;
}
auto res = std::make_shared<ASTColumnsReplaceTransformer>();
res->children = std::move(replacements);
res->is_strict = is_strict;
node = std::move(res);
return true;
}
return false;
}
bool ParserAsterisk::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (pos->type == TokenType::Asterisk)
{
++pos;
auto asterisk = std::make_shared<ASTAsterisk>();
auto transformers = std::make_shared<ASTColumnsTransformerList>();
ParserColumnsTransformers transformers_p(allowed_transformers);
ASTPtr transformer;
while (transformers_p.parse(pos, transformer, expected))
{
transformers->children.push_back(transformer);
}
if (!transformers->children.empty())
{
asterisk->transformers = std::move(transformers);
asterisk->children.push_back(asterisk->transformers);
}
node = std::move(asterisk);
return true;
}
return false;
}
bool ParserQualifiedAsterisk::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (!ParserCompoundIdentifier(false, true).parse(pos, node, expected))
return false;
if (pos->type != TokenType::Dot)
return false;
++pos;
if (pos->type != TokenType::Asterisk)
return false;
++pos;
auto res = std::make_shared<ASTQualifiedAsterisk>();
auto transformers = std::make_shared<ASTColumnsTransformerList>();
ParserColumnsTransformers transformers_p;
ASTPtr transformer;
while (transformers_p.parse(pos, transformer, expected))
{
transformers->children.push_back(transformer);
}
res->qualifier = std::move(node);
res->children.push_back(res->qualifier);
if (!transformers->children.empty())
{
res->transformers = std::move(transformers);
res->children.push_back(res->transformers);
}
node = std::move(res);
return true;
}
/// Parse (columns_list) or ('REGEXP').
static bool parseColumnsMatcherBody(IParser::Pos & pos, ASTPtr & node, Expected & expected, ParserColumnsTransformers::ColumnTransformers allowed_transformers)
{
if (pos->type != TokenType::OpeningRoundBracket)
return false;
++pos;
ParserList columns_p(std::make_unique<ParserCompoundIdentifier>(false, true), std::make_unique<ParserToken>(TokenType::Comma), false);
ParserStringLiteral regex;
ASTPtr column_list;
ASTPtr regex_node;
if (!columns_p.parse(pos, column_list, expected) && !regex.parse(pos, regex_node, expected))
return false;
if (pos->type != TokenType::ClosingRoundBracket)
return false;
++pos;
auto transformers = std::make_shared<ASTColumnsTransformerList>();
ParserColumnsTransformers transformers_p(allowed_transformers);
ASTPtr transformer;
while (transformers_p.parse(pos, transformer, expected))
{
transformers->children.push_back(transformer);
}
ASTPtr res;
if (column_list)
{
auto list_matcher = std::make_shared<ASTColumnsListMatcher>();
list_matcher->column_list = std::move(column_list);
list_matcher->children.push_back(list_matcher->column_list);
if (!transformers->children.empty())
{
list_matcher->transformers = std::move(transformers);
list_matcher->children.push_back(list_matcher->transformers);
}
node = std::move(list_matcher);
}
else
{
auto regexp_matcher = std::make_shared<ASTColumnsRegexpMatcher>();
regexp_matcher->setPattern(regex_node->as<ASTLiteral &>().value.get<String>());
if (!transformers->children.empty())
{
regexp_matcher->transformers = std::move(transformers);
regexp_matcher->children.push_back(regexp_matcher->transformers);
}
node = std::move(regexp_matcher);
}
return true;
}
bool ParserColumnsMatcher::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserKeyword columns("COLUMNS");
if (!columns.ignore(pos, expected))
return false;
return parseColumnsMatcherBody(pos, node, expected, allowed_transformers);
}
bool ParserQualifiedColumnsMatcher::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (!ParserCompoundIdentifier(false, true).parse(pos, node, expected))
return false;
auto identifier_node = node;
auto & identifier_node_typed = identifier_node->as<ASTIdentifier &>();
auto & name_parts = identifier_node_typed.name_parts;
/// ParserCompoundIdentifier parse identifier.COLUMNS
if (name_parts.size() == 1 || name_parts.back() != "COLUMNS")
return false;
name_parts.pop_back();
identifier_node = std::make_shared<ASTIdentifier>(std::move(name_parts), false, std::move(node->children));
if (!parseColumnsMatcherBody(pos, node, expected, allowed_transformers))
return false;
if (auto * columns_list_matcher = node->as<ASTColumnsListMatcher>())
{
auto result = std::make_shared<ASTQualifiedColumnsListMatcher>();
result->qualifier = std::move(identifier_node);
result->column_list = std::move(columns_list_matcher->column_list);
result->children.push_back(result->qualifier);
result->children.push_back(result->column_list);
if (columns_list_matcher->transformers)
{
result->transformers = std::move(columns_list_matcher->transformers);
result->children.push_back(result->transformers);
}
node = std::move(result);
}
else if (auto * column_regexp_matcher = node->as<ASTColumnsRegexpMatcher>())
{
auto result = std::make_shared<ASTQualifiedColumnsRegexpMatcher>();
result->setPattern(column_regexp_matcher->getPattern(), false);
result->setMatcher(column_regexp_matcher->getMatcher());
result->qualifier = std::move(identifier_node);
result->children.push_back(result->qualifier);
if (column_regexp_matcher->transformers)
{
result->transformers = std::move(column_regexp_matcher->transformers);
result->children.push_back(result->transformers);
}
node = std::move(result);
}
else
{
throw Exception(ErrorCodes::LOGICAL_ERROR, "Qualified COLUMNS matcher expected to be list or regexp");
}
return true;
}
bool ParserSubstitution::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (pos->type != TokenType::OpeningCurlyBrace)
return false;
++pos;
if (pos->type != TokenType::BareWord)
{
expected.add(pos, "substitution name (identifier)");
return false;
}
String name(pos->begin, pos->end);
++pos;
if (pos->type != TokenType::Colon)
{
expected.add(pos, "colon between name and type");
return false;
}
++pos;
auto old_pos = pos;
ParserDataType type_parser;
if (!type_parser.ignore(pos, expected))
{
expected.add(pos, "substitution type");
return false;
}
String type(old_pos->begin, pos->begin);
if (pos->type != TokenType::ClosingCurlyBrace)
{
expected.add(pos, "closing curly brace");
return false;
}
++pos;
node = std::make_shared<ASTQueryParameter>(name, type);
return true;
}
bool ParserMySQLGlobalVariable::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (pos->type != TokenType::DoubleAt)
return false;
++pos;
if (pos->type != TokenType::BareWord)
{
expected.add(pos, "variable name");
return false;
}
String name(pos->begin, pos->end);
++pos;
/// SELECT @@session|global.variable style
if (pos->type == TokenType::Dot)
{
++pos;
if (pos->type != TokenType::BareWord)
{
expected.add(pos, "variable name");
return false;
}
name = String(pos->begin, pos->end);
++pos;
}
auto name_literal = std::make_shared<ASTLiteral>(name);
node = makeASTFunction("globalVariable", name_literal);
node->setAlias("@@" + name);
return true;
}
bool ParserWithOptionalAlias::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
if (!elem_parser->parse(pos, node, expected))
return false;
/** Little hack.
*
* In the SELECT section, we allow parsing aliases without specifying the AS keyword.
* These aliases can not be the same as the query keywords.
* And the expression itself can be an identifier that matches the keyword.
* For example, a column may be called where. And in the query it can be written `SELECT where AS x FROM table` or even `SELECT where x FROM table`.
* Even can be written `SELECT where AS from FROM table`, but it can not be written `SELECT where from FROM table`.
* See the ParserAlias implementation for details.
*
* But there is a small problem - an inconvenient error message if there is an extra comma in the SELECT section at the end.
* Although this error is very common. Example: `SELECT x, y, z, FROM tbl`
* If you do nothing, it's parsed as a column with the name FROM and alias tbl.
* To avoid this situation, we do not allow the parsing of the alias without the AS keyword for the identifier with the name FROM.
*
* Note: this also filters the case when the identifier is quoted.
* Example: SELECT x, y, z, `FROM` tbl. But such a case could be solved.
*
* In the future it would be easier to disallow unquoted identifiers that match the keywords.
*/
bool allow_alias_without_as_keyword_now = allow_alias_without_as_keyword;
if (allow_alias_without_as_keyword)
if (auto opt_id = tryGetIdentifierName(node))
if (0 == strcasecmp(opt_id->data(), "FROM"))
allow_alias_without_as_keyword_now = false;
ASTPtr alias_node;
if (ParserAlias(allow_alias_without_as_keyword_now).parse(pos, alias_node, expected))
{
/// FIXME: try to prettify this cast using `as<>()`
if (auto * ast_with_alias = dynamic_cast<ASTWithAlias *>(node.get()))
{
tryGetIdentifierNameInto(alias_node, ast_with_alias->alias);
}
else
{
expected.add(pos, "alias cannot be here");
return false;
}
}
return true;
}
bool ParserOrderByElement::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserExpressionWithOptionalAlias elem_p(false);
ParserKeyword ascending("ASCENDING");
ParserKeyword descending("DESCENDING");
ParserKeyword asc("ASC");
ParserKeyword desc("DESC");
ParserKeyword nulls("NULLS");
ParserKeyword first("FIRST");
ParserKeyword last("LAST");
ParserKeyword collate("COLLATE");
ParserKeyword with_fill("WITH FILL");
ParserKeyword from("FROM");
ParserKeyword to("TO");
ParserKeyword step("STEP");
ParserStringLiteral collate_locale_parser;
ParserExpressionWithOptionalAlias exp_parser(false);
ASTPtr expr_elem;
if (!elem_p.parse(pos, expr_elem, expected))
return false;
int direction = 1;
if (descending.ignore(pos) || desc.ignore(pos))
direction = -1;
else
ascending.ignore(pos) || asc.ignore(pos);
int nulls_direction = direction;
bool nulls_direction_was_explicitly_specified = false;
if (nulls.ignore(pos))
{
nulls_direction_was_explicitly_specified = true;
if (first.ignore(pos))
nulls_direction = -direction;
else if (last.ignore(pos))
;
else
return false;
}
ASTPtr locale_node;
if (collate.ignore(pos))
{
if (!collate_locale_parser.parse(pos, locale_node, expected))
return false;
}
/// WITH FILL [FROM x] [TO y] [STEP z]
bool has_with_fill = false;
ASTPtr fill_from;
ASTPtr fill_to;
ASTPtr fill_step;
if (with_fill.ignore(pos))
{
has_with_fill = true;
if (from.ignore(pos) && !exp_parser.parse(pos, fill_from, expected))
return false;
if (to.ignore(pos) && !exp_parser.parse(pos, fill_to, expected))
return false;
if (step.ignore(pos) && !exp_parser.parse(pos, fill_step, expected))
return false;
}
auto elem = std::make_shared<ASTOrderByElement>();
elem->direction = direction;
elem->nulls_direction = nulls_direction;
elem->nulls_direction_was_explicitly_specified = nulls_direction_was_explicitly_specified;
elem->collation = locale_node;
elem->with_fill = has_with_fill;
elem->fill_from = fill_from;
elem->fill_to = fill_to;
elem->fill_step = fill_step;
elem->children.push_back(expr_elem);
if (locale_node)
elem->children.push_back(locale_node);
node = elem;
return true;
}
bool ParserInterpolateElement::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserKeyword as("AS");
ParserExpression element_p;
ParserIdentifier ident_p;
ASTPtr ident;
if (!ident_p.parse(pos, ident, expected))
return false;
ASTPtr expr;
if (as.ignore(pos, expected))
{
if (!element_p.parse(pos, expr, expected))
return false;
}
else
expr = ident;
auto elem = std::make_shared<ASTInterpolateElement>();
elem->column = ident->getColumnName();
elem->expr = expr;
elem->children.push_back(expr);
node = elem;
return true;
}
bool ParserFunctionWithKeyValueArguments::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserIdentifier id_parser;
ParserKeyValuePairsList pairs_list_parser;
ASTPtr identifier;
ASTPtr expr_list_args;
if (!id_parser.parse(pos, identifier, expected))
return false;
bool left_bracket_found = false;
if (pos.get().type != TokenType::OpeningRoundBracket)
{
if (!brackets_can_be_omitted)
return false;
}
else
{
++pos;
left_bracket_found = true;
}
if (!pairs_list_parser.parse(pos, expr_list_args, expected))
return false;
if (left_bracket_found)
{
if (pos.get().type != TokenType::ClosingRoundBracket)
return false;
++pos;
}
auto function = std::make_shared<ASTFunctionWithKeyValueArguments>(left_bracket_found);
function->name = Poco::toLower(identifier->as<ASTIdentifier>()->name());
function->elements = expr_list_args;
function->children.push_back(function->elements);
node = function;
return true;
}
bool ParserTTLElement::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserKeyword s_to_disk("TO DISK");
ParserKeyword s_to_volume("TO VOLUME");
ParserKeyword s_if_exists("IF EXISTS");
ParserKeyword s_delete("DELETE");
ParserKeyword s_where("WHERE");
ParserKeyword s_group_by("GROUP BY");
ParserKeyword s_set("SET");
ParserKeyword s_recompress("RECOMPRESS");
ParserKeyword s_codec("CODEC");
ParserKeyword s_materialize("MATERIALIZE");
ParserKeyword s_remove("REMOVE");
ParserKeyword s_modify("MODIFY");
ParserIdentifier parser_identifier;
ParserStringLiteral parser_string_literal;
ParserExpression parser_exp;
ParserExpressionList parser_keys_list(false);
ParserCodec parser_codec;
if (s_materialize.checkWithoutMoving(pos, expected) ||
s_remove.checkWithoutMoving(pos, expected) ||
s_modify.checkWithoutMoving(pos, expected))
return false;
ASTPtr ttl_expr;
if (!parser_exp.parse(pos, ttl_expr, expected))
return false;
TTLMode mode;
DataDestinationType destination_type = DataDestinationType::DELETE;
String destination_name;
if (s_to_disk.ignore(pos))
{
mode = TTLMode::MOVE;
destination_type = DataDestinationType::DISK;
}
else if (s_to_volume.ignore(pos))
{
mode = TTLMode::MOVE;
destination_type = DataDestinationType::VOLUME;
}
else if (s_group_by.ignore(pos))
{
mode = TTLMode::GROUP_BY;
}
else if (s_recompress.ignore(pos))
{
mode = TTLMode::RECOMPRESS;
}
else
{
s_delete.ignore(pos);
mode = TTLMode::DELETE;
}
ASTPtr where_expr;
ASTPtr group_by_key;
ASTPtr recompression_codec;
ASTPtr group_by_assignments;
bool if_exists = false;
if (mode == TTLMode::MOVE)
{
if (s_if_exists.ignore(pos))
if_exists = true;
ASTPtr ast_space_name;
if (!parser_string_literal.parse(pos, ast_space_name, expected))
return false;
destination_name = ast_space_name->as<ASTLiteral &>().value.get<const String &>();
}
else if (mode == TTLMode::GROUP_BY)
{
if (!parser_keys_list.parse(pos, group_by_key, expected))
return false;
if (s_set.ignore(pos))
{
ParserList parser_assignment_list(
std::make_unique<ParserAssignment>(), std::make_unique<ParserToken>(TokenType::Comma));
if (!parser_assignment_list.parse(pos, group_by_assignments, expected))
return false;
}
}
else if (mode == TTLMode::DELETE && s_where.ignore(pos))
{
if (!parser_exp.parse(pos, where_expr, expected))
return false;
}
else if (mode == TTLMode::RECOMPRESS)
{
if (!s_codec.ignore(pos))
return false;
if (!parser_codec.parse(pos, recompression_codec, expected))
return false;
}
auto ttl_element = std::make_shared<ASTTTLElement>(mode, destination_type, destination_name, if_exists);
ttl_element->setTTL(std::move(ttl_expr));
if (where_expr)
ttl_element->setWhere(std::move(where_expr));
if (mode == TTLMode::GROUP_BY)
{
ttl_element->group_by_key = std::move(group_by_key->children);
if (group_by_assignments)
ttl_element->group_by_assignments = std::move(group_by_assignments->children);
}
if (mode == TTLMode::RECOMPRESS)
ttl_element->recompression_codec = recompression_codec;
node = ttl_element;
return true;
}
bool ParserIdentifierWithOptionalParameters::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
ParserIdentifier non_parametric;
ParserIdentifierWithParameters parametric;
if (parametric.parse(pos, node, expected))
{
auto * func = node->as<ASTFunction>();
func->no_empty_args = true;
return true;
}
ASTPtr ident;
if (non_parametric.parse(pos, ident, expected))
{
auto func = std::make_shared<ASTFunction>();
tryGetIdentifierNameInto(ident, func->name);
func->no_empty_args = true;
node = func;
return true;
}
return false;
}
bool ParserAssignment::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
auto assignment = std::make_shared<ASTAssignment>();
node = assignment;
ParserIdentifier p_identifier;
ParserToken s_equals(TokenType::Equals);
ParserExpression p_expression;
ASTPtr column;
if (!p_identifier.parse(pos, column, expected))
return false;
if (!s_equals.ignore(pos, expected))
return false;
ASTPtr expression;
if (!p_expression.parse(pos, expression, expected))
return false;
tryGetIdentifierNameInto(column, assignment->column_name);
if (expression)
assignment->children.push_back(expression);
return true;
}
}