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support for IF EXISTS/IF NOT EXISTS in ALTER TABLE ADD/DROP/CLEAR/MODIFY/COMMENT COLUMN

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This commit is contained in:
Boris Granveaud 2018-12-21 15:53:00 +01:00
parent d7ac2b3afd
commit d776d1164a
7 changed files with 108 additions and 39 deletions
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6
dbms/src/Parsers/ASTAlterQuery.cpp
View File

@ -51,7 +51,7 @@ void ASTAlterCommand::formatImpl(
if (type == ASTAlterCommand::ADD_COLUMN)
{
settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << "ADD COLUMN " << (settings.hilite ? hilite_none : "");
settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << "ADD COLUMN " << (if_not_exists ? "IF NOT EXISTS " : "") << (settings.hilite ? hilite_none : "");
col_decl->formatImpl(settings, state, frame);
/// AFTER
@ -64,7 +64,7 @@ void ASTAlterCommand::formatImpl(
else if (type == ASTAlterCommand::DROP_COLUMN)
{
settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str
<< (clear_column ? "CLEAR " : "DROP ") << "COLUMN " << (settings.hilite ? hilite_none : "");
<< (clear_column ? "CLEAR " : "DROP ") << "COLUMN " << (if_exists ? "IF EXISTS " : "") << (settings.hilite ? hilite_none : "");
column->formatImpl(settings, state, frame);
if (partition)
{
@ -74,7 +74,7 @@ void ASTAlterCommand::formatImpl(
}
else if (type == ASTAlterCommand::MODIFY_COLUMN)
{
settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << "MODIFY COLUMN " << (settings.hilite ? hilite_none : "");
settings.ostr << (settings.hilite ? hilite_keyword : "") << indent_str << "MODIFY COLUMN " << (if_exists ? "IF EXISTS " : "") << (settings.hilite ? hilite_none : "");
col_decl->formatImpl(settings, state, frame);
}
else if (type == ASTAlterCommand::MODIFY_ORDER_BY)

4
dbms/src/Parsers/ASTAlterQuery.h
View File

@ -78,6 +78,10 @@ public:
bool clear_column = false; /// for CLEAR COLUMN (do not drop column from metadata)
bool if_not_exists = false; /// option for ADD_COLUMN
bool if_exists = false; /// option for DROP_COLUMN, MODIFY_COLUMN, COMMENT_COLUMN
/** For FETCH PARTITION - the path in ZK to the shard, from which to download the partition.
*/
String from;

17
dbms/src/Parsers/ParserAlterQuery.cpp
View File

@ -36,6 +36,8 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
ParserKeyword s_partition("PARTITION");
ParserKeyword s_after("AFTER");
ParserKeyword s_if_not_exists("IF NOT EXISTS");
ParserKeyword s_if_exists("IF EXISTS");
ParserKeyword s_from("FROM");
ParserKeyword s_in_partition("IN PARTITION");
ParserKeyword s_with("WITH");
@ -57,6 +59,9 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
if (s_add_column.ignore(pos, expected))
{
if (s_if_not_exists.ignore(pos, expected))
command->if_not_exists = true;
if (!parser_col_decl.parse(pos, command->col_decl, expected))
return false;
@ -77,6 +82,9 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
}
else if (s_drop_column.ignore(pos, expected))
{
if (s_if_exists.ignore(pos, expected))
command->if_exists = true;
if (!parser_name.parse(pos, command->column, expected))
return false;
@ -85,6 +93,9 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
}
else if (s_clear_column.ignore(pos, expected))
{
if (s_if_exists.ignore(pos, expected))
command->if_exists = true;
if (!parser_name.parse(pos, command->column, expected))
return false;
@ -190,6 +201,9 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
}
else if (s_modify_column.ignore(pos, expected))
{
if (s_if_exists.ignore(pos, expected))
command->if_exists = true;
if (!parser_modify_col_decl.parse(pos, command->col_decl, expected))
return false;
@ -224,6 +238,9 @@ bool ParserAlterCommand::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
}
else if (s_comment_column.ignore(pos, expected))
{
if (s_if_exists.ignore(pos, expected))
command->if_exists = true;
if (!parser_name.parse(pos, command->column, expected))
return false;

10
dbms/src/Parsers/ParserAlterQuery.h
View File

@ -8,12 +8,12 @@ namespace DB
/** Query like this:
* ALTER TABLE [db.]name [ON CLUSTER cluster]
* [ADD COLUMN col_name type [AFTER col_after],]
* [DROP COLUMN col_to_drop, ...]
* [CLEAR COLUMN col_to_clear [IN PARTITION partition],]
* [MODIFY COLUMN col_to_modify type, ...]
* [ADD COLUMN [IF NOT EXISTS] col_name type [AFTER col_after],]
* [DROP COLUMN [IF EXISTS] col_to_drop, ...]
* [CLEAR COLUMN [IF EXISTS] col_to_clear [IN PARTITION partition],]
* [MODIFY COLUMN [IF EXISTS] col_to_modify type, ...]
* [MODIFY PRIMARY KEY (a, b, c...)]
* [COMMENT COLUMN col_name string]
* [COMMENT COLUMN [IF EXISTS] col_name string]
* [DROP|DETACH|ATTACH PARTITION|PART partition, ...]
* [FETCH PARTITION partition FROM ...]
* [FREEZE [PARTITION] [WITH NAME name]]

88
dbms/src/Storages/AlterCommands.cpp
View File

@ -52,6 +52,8 @@ std::optional<AlterCommand> AlterCommand::parse(const ASTAlterCommand * command_
if (command_ast->column)
command.after_column = typeid_cast<const ASTIdentifier &>(*command_ast->column).name;
command.if_not_exists = command_ast->if_not_exists;
return command;
}
else if (command_ast->type == ASTAlterCommand::DROP_COLUMN && !command_ast->partition)
@ -62,6 +64,7 @@ std::optional<AlterCommand> AlterCommand::parse(const ASTAlterCommand * command_
AlterCommand command;
command.type = AlterCommand::DROP_COLUMN;
command.column_name = typeid_cast<const ASTIdentifier &>(*(command_ast->column)).name;
command.if_exists = command_ast->if_exists;
return command;
}
else if (command_ast->type == ASTAlterCommand::MODIFY_COLUMN)
@ -88,6 +91,7 @@ std::optional<AlterCommand> AlterCommand::parse(const ASTAlterCommand * command_
const auto & ast_comment = typeid_cast<ASTLiteral &>(*ast_col_decl.comment);
command.comment = ast_comment.value.get<String>();
}
command.if_exists = command_ast->if_exists;
return command;
}
@ -99,6 +103,7 @@ std::optional<AlterCommand> AlterCommand::parse(const ASTAlterCommand * command_
command.column_name = ast_identifier.name;
const auto & ast_comment = typeid_cast<ASTLiteral &>(*command_ast->comment);
command.comment = ast_comment.value.get<String>();
command.if_exists = command_ast->if_exists;
return command;
}
else if (command_ast->type == ASTAlterCommand::MODIFY_ORDER_BY)
@ -300,7 +305,8 @@ void AlterCommands::apply(ColumnsDescription & columns_description, ASTPtr & ord
auto new_primary_key_ast = primary_key_ast;
for (const AlterCommand & command : *this)
command.apply(new_columns_description, new_order_by_ast, new_primary_key_ast);
if (!command.ignore)
command.apply(new_columns_description, new_order_by_ast, new_primary_key_ast);
columns_description = std::move(new_columns_description);
order_by_ast = std::move(new_order_by_ast);
@ -328,45 +334,61 @@ void AlterCommands::validate(const IStorage & table, const Context & context)
if (command.type == AlterCommand::ADD_COLUMN)
{
if (std::end(all_columns) != column_it)
throw Exception{"Cannot add column " + column_name + ": column with this name already exists", ErrorCodes::ILLEGAL_COLUMN};
{
if (command.if_not_exists)
command.ignore = true;
else
throw Exception{"Cannot add column " + column_name + ": column with this name already exists", ErrorCodes::ILLEGAL_COLUMN};
}
}
else if (command.type == AlterCommand::MODIFY_COLUMN)
{
if (std::end(all_columns) == column_it)
throw Exception{"Wrong column name. Cannot find column " + column_name + " to modify", ErrorCodes::ILLEGAL_COLUMN};
{
if (command.if_exists)
command.ignore = true;
else
throw Exception{"Wrong column name. Cannot find column " + column_name + " to modify", ErrorCodes::ILLEGAL_COLUMN};
}
all_columns.erase(column_it);
defaults.erase(column_name);
if (!command.ignore)
{
all_columns.erase(column_it);
defaults.erase(column_name);
}
}
/// we're creating dummy DataTypeUInt8 in order to prevent the NullPointerException in ExpressionActions
all_columns.emplace_back(column_name, command.data_type ? command.data_type : std::make_shared<DataTypeUInt8>());
if (command.default_expression)
if (!command.ignore)
{
if (command.data_type)
/// we're creating dummy DataTypeUInt8 in order to prevent the NullPointerException in ExpressionActions
all_columns.emplace_back(column_name, command.data_type ? command.data_type : std::make_shared<DataTypeUInt8>());
if (command.default_expression)
{
const auto & final_column_name = column_name;
const auto tmp_column_name = final_column_name + "_tmp";
const auto column_type_raw_ptr = command.data_type.get();
if (command.data_type)
{
const auto &final_column_name = column_name;
const auto tmp_column_name = final_column_name + "_tmp";
const auto column_type_raw_ptr = command.data_type.get();
default_expr_list->children.emplace_back(setAlias(
makeASTFunction("CAST", std::make_shared<ASTIdentifier>(tmp_column_name),
std::make_shared<ASTLiteral>(column_type_raw_ptr->getName())),
final_column_name));
default_expr_list->children.emplace_back(setAlias(
makeASTFunction("CAST", std::make_shared<ASTIdentifier>(tmp_column_name),
std::make_shared<ASTLiteral>(column_type_raw_ptr->getName())),
final_column_name));
default_expr_list->children.emplace_back(setAlias(command.default_expression->clone(), tmp_column_name));
default_expr_list->children.emplace_back(setAlias(command.default_expression->clone(), tmp_column_name));
defaulted_columns.emplace_back(NameAndTypePair{column_name, command.data_type}, &command);
}
else
{
/// no type explicitly specified, will deduce later
default_expr_list->children.emplace_back(
setAlias(command.default_expression->clone(), column_name));
defaulted_columns.emplace_back(NameAndTypePair{column_name, command.data_type}, &command);
}
else
{
/// no type explicitly specified, will deduce later
default_expr_list->children.emplace_back(
setAlias(command.default_expression->clone(), column_name));
defaulted_columns.emplace_back(NameAndTypePair{column_name, nullptr}, &command);
defaulted_columns.emplace_back(NameAndTypePair{column_name, nullptr}, &command);
}
}
}
}
@ -407,8 +429,13 @@ void AlterCommands::validate(const IStorage & table, const Context & context)
}
if (!found)
throw Exception("Wrong column name. Cannot find column " + command.column_name + " to drop",
ErrorCodes::ILLEGAL_COLUMN);
{
if (command.if_exists)
command.ignore = true;
else
throw Exception("Wrong column name. Cannot find column " + command.column_name + " to drop",
ErrorCodes::ILLEGAL_COLUMN);
}
}
else if (command.type == AlterCommand::COMMENT_COLUMN)
{
@ -416,7 +443,10 @@ void AlterCommands::validate(const IStorage & table, const Context & context)
std::bind(namesEqual, std::cref(command.column_name), std::placeholders::_1));
if (column_it == std::end(all_columns))
{
throw Exception{"Wrong column name. Cannot find column " + command.column_name + " to comment", ErrorCodes::ILLEGAL_COLUMN};
if (command.if_exists)
command.ignore = true;
else
throw Exception{"Wrong column name. Cannot find column " + command.column_name + " to comment", ErrorCodes::ILLEGAL_COLUMN};
}
}
}

15
dbms/src/Storages/AlterCommands.h
View File

@ -43,15 +43,26 @@ struct AlterCommand
/// For ADD - after which column to add a new one. If an empty string, add to the end. To add to the beginning now it is impossible.
String after_column;
/// For DROP_COLUMN, MODIFY_COLUMN, COMMENT_COLUMN
bool if_exists;
/// For ADD_COLUMN
bool if_not_exists;
/// For MODIFY_ORDER_BY
ASTPtr order_by;
/// indicates that this command should not be applied, for example in case of if_exists=true and column doesn't exist.
bool ignore = false;
AlterCommand() = default;
AlterCommand(const Type type, const String & column_name, const DataTypePtr & data_type,
const ColumnDefaultKind default_kind, const ASTPtr & default_expression,
const String & after_column = String{}, const String & comment = "") // TODO: разобраться здесь с параметром по умолчанию
const String & after_column = String{}, const String & comment = "",
const bool if_exists = false, const bool if_not_exists = false) // TODO: разобраться здесь с параметром по умолчанию
: type{type}, column_name{column_name}, data_type{data_type}, default_kind{default_kind},
default_expression{default_expression}, comment(comment), after_column{after_column}
default_expression{default_expression}, comment(comment), after_column{after_column},
if_exists(if_exists), if_not_exists(if_not_exists)
{}
static std::optional<AlterCommand> parse(const ASTAlterCommand * command);

7
dbms/tests/queries/0_stateless/00030_alter_table.sql
View File

@ -23,6 +23,13 @@ ALTER TABLE test.alter_test DROP COLUMN NestedColumn.S;
ALTER TABLE test.alter_test DROP COLUMN AddedNested1.B;
ALTER TABLE test.alter_test ADD COLUMN IF NOT EXISTS Added0 UInt32;
ALTER TABLE test.alter_test ADD COLUMN IF NOT EXISTS AddedNested1 Nested(A UInt32, B UInt64);
ALTER TABLE test.alter_test ADD COLUMN IF NOT EXISTS AddedNested1.C Array(String);
ALTER TABLE test.alter_test MODIFY COLUMN IF EXISTS ToDrop UInt64;
ALTER TABLE test.alter_test DROP COLUMN IF EXISTS ToDrop;
ALTER TABLE test.alter_test COMMENT COLUMN IF EXISTS ToDrop 'new comment';
DESC TABLE test.alter_test;
SELECT * FROM test.alter_test;