ClickHouse/dbms/src/Parsers/ParserCreateQuery.cpp

#include <Common/typeid_cast.h>
#include <Parsers/ASTFunction.h>
#include <Parsers/ASTIdentifier.h>
#include <Parsers/ASTIndexDeclaration.h>
#include <Parsers/ASTExpressionList.h>
#include <Parsers/ASTCreateQuery.h>
#include <Parsers/ASTSetQuery.h>
#include <Parsers/ASTSelectWithUnionQuery.h>
#include <Parsers/ExpressionListParsers.h>
#include <Parsers/ParserCreateQuery.h>
#include <Parsers/ParserSelectWithUnionQuery.h>
#include <Parsers/ParserSetQuery.h>


namespace DB
{

bool ParserNestedTable::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ParserToken open(TokenType::OpeningRoundBracket);
    ParserToken close(TokenType::ClosingRoundBracket);
    ParserIdentifier name_p;
    ParserNameTypePairList columns_p;

    ASTPtr name;
    ASTPtr columns;

    /// For now `name == 'Nested'`, probably alternative nested data structures will appear
    if (!name_p.parse(pos, name, expected))
        return false;

    if (!open.ignore(pos))
        return false;

    if (!columns_p.parse(pos, columns, expected))
        return false;

    if (!close.ignore(pos))
        return false;

    auto func = std::make_shared<ASTFunction>();
    getIdentifierName(name, func->name);
    func->arguments = columns;
    func->children.push_back(columns);
    node = func;

    return true;
}


bool ParserIdentifierWithParameters::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ParserFunction function_or_array;
    if (function_or_array.parse(pos, node, expected))
        return true;

    ParserNestedTable nested;
    if (nested.parse(pos, node, expected))
        return true;

    return false;
}


bool ParserIdentifierWithOptionalParameters::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ParserIdentifier non_parametric;
    ParserIdentifierWithParameters parametric;

    if (parametric.parse(pos, node, expected))
        return true;

    ASTPtr ident;
    if (non_parametric.parse(pos, ident, expected))
    {
        auto func = std::make_shared<ASTFunction>();
        getIdentifierName(ident, func->name);
        node = func;
        return true;
    }

    return false;
}

bool ParserNameTypePairList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    return ParserList(std::make_unique<ParserNameTypePair>(), std::make_unique<ParserToken>(TokenType::Comma), false)
        .parse(pos, node, expected);
}

bool ParserColumnDeclarationList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    return ParserList(std::make_unique<ParserColumnDeclaration>(), std::make_unique<ParserToken>(TokenType::Comma), false)
        .parse(pos, node, expected);
}

bool ParserIndexDeclaration::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ParserKeyword s_type("TYPE");
    ParserKeyword s_granularity("GRANULARITY");

    ParserIdentifier name_p;
    ParserIdentifierWithOptionalParameters ident_with_optional_params_p;
    ParserExpression expression_p;
    ParserUnsignedInteger granularity_p;

    ASTPtr name;
    ASTPtr expr;
    ASTPtr type;
    ASTPtr granularity;

    if (!name_p.parse(pos, name, expected))
        return false;

    if (!expression_p.parse(pos, expr, expected))
        return false;

    if (!s_type.ignore(pos, expected))
        return false;

    if (!ident_with_optional_params_p.parse(pos, type, expected))
        return false;

    if (!s_granularity.ignore(pos, expected))
        return false;

    if (!granularity_p.parse(pos, granularity, expected))
        return false;

    auto index = std::make_shared<ASTIndexDeclaration>();
    index->name = name->as<ASTIdentifier &>().name;
    index->granularity = granularity->as<ASTLiteral &>().value.get<UInt64>();
    index->set(index->expr, expr);
    index->set(index->type, type);
    node = index;

    return true;
}


bool ParserColumnAndIndexDeclaraion::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ParserKeyword s_index("INDEX");

    ParserIndexDeclaration index_p;
    ParserColumnDeclaration column_p;

    ASTPtr new_node = nullptr;

    if (s_index.ignore(pos, expected))
    {
        if (!index_p.parse(pos, new_node, expected))
            return false;
    }
    else
    {
        if (!column_p.parse(pos, new_node, expected))
            return false;
    }

    node = new_node;
    return true;
}

bool ParserIndexDeclarationList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    return ParserList(std::make_unique<ParserIndexDeclaration>(), std::make_unique<ParserToken>(TokenType::Comma), false)
            .parse(pos, node, expected);
}


bool ParserColumnsOrIndicesDeclarationList::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ASTPtr list;
    if (!ParserList(std::make_unique<ParserColumnAndIndexDeclaraion>(), std::make_unique<ParserToken>(TokenType::Comma), false)
            .parse(pos, list, expected))
        return false;

    ASTPtr columns = std::make_shared<ASTExpressionList>();
    ASTPtr indices = std::make_shared<ASTExpressionList>();

    for (const auto & elem : list->children)
    {
        if (elem->as<ASTColumnDeclaration>())
            columns->children.push_back(elem);
        else if (elem->as<ASTIndexDeclaration>())
            indices->children.push_back(elem);
        else
            return false;
    }

    auto res = std::make_shared<ASTColumns>();

    if (!columns->children.empty())
        res->set(res->columns, columns);
    if (!indices->children.empty())
        res->set(res->indices, indices);

    node = res;

    return true;
}


bool ParserStorage::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ParserKeyword s_engine("ENGINE");
    ParserToken s_eq(TokenType::Equals);
    ParserKeyword s_partition_by("PARTITION BY");
    ParserKeyword s_primary_key("PRIMARY KEY");
    ParserKeyword s_order_by("ORDER BY");
    ParserKeyword s_sample_by("SAMPLE BY");
    ParserKeyword s_ttl("TTL");
    ParserKeyword s_settings("SETTINGS");

    ParserIdentifierWithOptionalParameters ident_with_optional_params_p;
    ParserExpression expression_p;
    ParserSetQuery settings_p(/* parse_only_internals_ = */ true);

    ASTPtr engine;
    ASTPtr partition_by;
    ASTPtr primary_key;
    ASTPtr order_by;
    ASTPtr sample_by;
    ASTPtr ttl_table;
    ASTPtr settings;

    if (!s_engine.ignore(pos, expected))
        return false;

    s_eq.ignore(pos, expected);

    if (!ident_with_optional_params_p.parse(pos, engine, expected))
        return false;

    while (true)
    {
        if (!partition_by && s_partition_by.ignore(pos, expected))
        {
            if (expression_p.parse(pos, partition_by, expected))
                continue;
            else
                return false;
        }

        if (!primary_key && s_primary_key.ignore(pos, expected))
        {
            if (expression_p.parse(pos, primary_key, expected))
                continue;
            else
                return false;
        }

        if (!order_by && s_order_by.ignore(pos, expected))
        {
            if (expression_p.parse(pos, order_by, expected))
                continue;
            else
                return false;
        }

        if (!sample_by && s_sample_by.ignore(pos, expected))
        {
            if (expression_p.parse(pos, sample_by, expected))
                continue;
            else
                return false;
        }

        if (!ttl_table && s_ttl.ignore(pos, expected))
        {
            if (expression_p.parse(pos, ttl_table, expected))
                continue;
            else
                return false;
        }

        if (s_settings.ignore(pos, expected))
        {
            if (!settings_p.parse(pos, settings, expected))
                return false;
        }

        break;
    }

    auto storage = std::make_shared<ASTStorage>();
    storage->set(storage->engine, engine);
    storage->set(storage->partition_by, partition_by);
    storage->set(storage->primary_key, primary_key);
    storage->set(storage->order_by, order_by);
    storage->set(storage->sample_by, sample_by);
    storage->set(storage->ttl_table, ttl_table);

    storage->set(storage->settings, settings);

    node = storage;
    return true;
}


bool ParserCreateQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ParserKeyword s_create("CREATE");
    ParserKeyword s_temporary("TEMPORARY");
    ParserKeyword s_attach("ATTACH");
    ParserKeyword s_table("TABLE");
    ParserKeyword s_database("DATABASE");
    ParserKeyword s_if_not_exists("IF NOT EXISTS");
    ParserKeyword s_as("AS");
    ParserKeyword s_view("VIEW");
    ParserKeyword s_materialized("MATERIALIZED");
    ParserKeyword s_populate("POPULATE");
    ParserKeyword s_or_replace("OR REPLACE");
    ParserToken s_dot(TokenType::Dot);
    ParserToken s_lparen(TokenType::OpeningRoundBracket);
    ParserToken s_rparen(TokenType::ClosingRoundBracket);
    ParserStorage storage_p;
    ParserIdentifier name_p;
    ParserColumnsOrIndicesDeclarationList columns_or_indices_p;
    ParserSelectWithUnionQuery select_p;
    ParserFunction table_function_p;

    ASTPtr database;
    ASTPtr table;
    ASTPtr columns_list;
    ASTPtr to_database;
    ASTPtr to_table;
    ASTPtr storage;
    ASTPtr as_database;
    ASTPtr as_table;
    ASTPtr as_table_function;
    ASTPtr select;
    String cluster_str;
    bool attach = false;
    bool if_not_exists = false;
    bool is_view = false;
    bool is_materialized_view = false;
    bool is_populate = false;
    bool is_temporary = false;
    bool replace_view = false;

    if (!s_create.ignore(pos, expected))
    {
        if (s_attach.ignore(pos, expected))
            attach = true;
        else
            return false;
    }

    if (s_temporary.ignore(pos, expected))
    {
        is_temporary = true;
    }

    if (s_table.ignore(pos, expected))
    {
        if (s_if_not_exists.ignore(pos, expected))
            if_not_exists = true;

        if (!name_p.parse(pos, table, expected))
            return false;

        if (s_dot.ignore(pos, expected))
        {
            database = table;
            if (!name_p.parse(pos, table, expected))
                return false;
        }

        if (ParserKeyword{"ON"}.ignore(pos, expected))
        {
            if (!ASTQueryWithOnCluster::parse(pos, cluster_str, expected))
                return false;
        }

        // Shortcut for ATTACH a previously detached table
        if (attach && (!pos.isValid() || pos.get().type == TokenType::Semicolon))
        {
            auto query = std::make_shared<ASTCreateQuery>();
            node = query;

            query->attach = attach;
            query->if_not_exists = if_not_exists;
            query->cluster = cluster_str;

            getIdentifierName(database, query->database);
            getIdentifierName(table, query->table);

            return true;
        }

        /// List of columns.
        if (s_lparen.ignore(pos, expected))
        {
            if (!columns_or_indices_p.parse(pos, columns_list, expected))
                return false;

            if (!s_rparen.ignore(pos, expected))
                return false;

            if (!storage_p.parse(pos, storage, expected) && !is_temporary)
                return false;
        }
        else
        {
            storage_p.parse(pos, storage, expected);

            if (!s_as.ignore(pos, expected))
                return false;

            if (!table_function_p.parse(pos, as_table_function, expected))
            {
                if (!select_p.parse(pos, select, expected)) /// AS SELECT ...
                {
                    /// AS [db.]table
                    if (!name_p.parse(pos, as_table, expected))
                        return false;

                    if (s_dot.ignore(pos, expected))
                    {
                        as_database = as_table;
                        if (!name_p.parse(pos, as_table, expected))
                            return false;
                    }

                    /// Optional - ENGINE can be specified.
                    if (!storage)
                        storage_p.parse(pos, storage, expected);
                }
            }
        }
    }
    else if (is_temporary)
        return false;
    else if (s_database.ignore(pos, expected))
    {
        if (s_if_not_exists.ignore(pos, expected))
            if_not_exists = true;

        if (!name_p.parse(pos, database, expected))
            return false;

        if (ParserKeyword{"ON"}.ignore(pos, expected))
        {
            if (!ASTQueryWithOnCluster::parse(pos, cluster_str, expected))
                return false;
        }

        storage_p.parse(pos, storage, expected);
    }
    else
    {
        /// VIEW or MATERIALIZED VIEW
        if (s_or_replace.ignore(pos, expected))
        {
            replace_view = true;
        }

        if (!replace_view && s_materialized.ignore(pos, expected))
        {
            is_materialized_view = true;
        }
        else
            is_view = true;

        if (!s_view.ignore(pos, expected))
            return false;

        if (!replace_view && s_if_not_exists.ignore(pos, expected))
            if_not_exists = true;

        if (!name_p.parse(pos, table, expected))
            return false;

        if (s_dot.ignore(pos, expected))
        {
            database = table;
            if (!name_p.parse(pos, table, expected))
                return false;
        }

        if (ParserKeyword{"ON"}.ignore(pos, expected))
        {
            if (!ASTQueryWithOnCluster::parse(pos, cluster_str, expected))
                return false;
        }

        // TO [db.]table
        if (ParserKeyword{"TO"}.ignore(pos, expected))
        {
            if (!name_p.parse(pos, to_table, expected))
                return false;

            if (s_dot.ignore(pos, expected))
            {
                to_database = to_table;
                if (!name_p.parse(pos, to_table, expected))
                    return false;
            }
        }

        /// Optional - a list of columns can be specified. It must fully comply with SELECT.
        if (s_lparen.ignore(pos, expected))
        {
            if (!columns_or_indices_p.parse(pos, columns_list, expected))
                return false;

            if (!s_rparen.ignore(pos, expected))
                return false;
        }

        if (is_materialized_view && !to_table)
        {
            /// Internal ENGINE for MATERIALIZED VIEW must be specified.
            if (!storage_p.parse(pos, storage, expected))
                return false;

            if (s_populate.ignore(pos, expected))
                is_populate = true;
        }

        /// AS SELECT ...
        if (!s_as.ignore(pos, expected))
            return false;

        if (!select_p.parse(pos, select, expected))
            return false;
    }

    auto query = std::make_shared<ASTCreateQuery>();
    node = query;

    if (as_table_function)
        query->as_table_function = as_table_function;

    query->attach = attach;
    query->if_not_exists = if_not_exists;
    query->is_view = is_view;
    query->is_materialized_view = is_materialized_view;
    query->is_populate = is_populate;
    query->temporary = is_temporary;
    query->replace_view = replace_view;

    getIdentifierName(database, query->database);
    getIdentifierName(table, query->table);
    query->cluster = cluster_str;

    getIdentifierName(to_database, query->to_database);
    getIdentifierName(to_table, query->to_table);

    query->set(query->columns_list, columns_list);
    query->set(query->storage, storage);

    getIdentifierName(as_database, query->as_database);
    getIdentifierName(as_table, query->as_table);
    query->set(query->select, select);

    return true;
}


}