ClickHouse/src/Parsers/ParserPartition.cpp

#include <Parsers/ParserPartition.h>
#include <Parsers/CommonParsers.h>
#include <Parsers/ExpressionElementParsers.h>
#include <Parsers/ExpressionListParsers.h>
#include <Parsers/ASTPartition.h>
#include <Parsers/ASTLiteral.h>
#include <Parsers/ASTFunction.h>
#include <Parsers/ASTIdentifier.h>
#include <Common/typeid_cast.h>
#include <Parsers/ASTQueryParameter.h>

namespace DB
{

bool ParserPartition::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
{
    ParserKeyword s_id("ID");
    ParserKeyword s_all("ALL");
    ParserStringLiteral parser_string_literal;
    ParserSubstitution parser_substitution;
    ParserLiteral literal_parser;
    ParserTupleOfLiterals tuple_of_literals;
    ParserExpression parser_expr;

    auto partition = std::make_shared<ASTPartition>();

    if (s_id.ignore(pos, expected))
    {
        ASTPtr partition_id;
        if (!parser_string_literal.parse(pos, partition_id, expected) && !parser_substitution.parse(pos, partition_id, expected))
            return false;

        if (auto * partition_id_literal = partition_id->as<ASTLiteral>(); partition_id_literal != nullptr)
            partition->setPartitionID(partition_id);
        else if (auto * partition_id_query_parameter = partition_id->as<ASTQueryParameter>(); partition_id_query_parameter != nullptr)
            partition->setPartitionID(partition_id);
        else
            return false;
    }
    else if (s_all.ignore(pos, expected))
    {
        partition->all = true;
    }
    else
    {
        ASTPtr value;
        std::optional<size_t> fields_count;
        if (literal_parser.parse(pos, value, expected) || tuple_of_literals.parse(pos, value, expected))
        {
            auto * literal = value->as<ASTLiteral>();
            if (literal->value.getType() == Field::Types::Tuple)
            {
                fields_count = literal->value.get<const Tuple &>().size();
            }
            else
            {
                fields_count = 1;
            }
        }
        else if (parser_substitution.parse(pos, value, expected))
        {
            /// It can be tuple substitution
            fields_count = std::nullopt;
        }
        else if (parser_expr.parse(pos, value, expected))
        {
            const auto * tuple_ast = value->as<ASTFunction>();
            if (tuple_ast && tuple_ast->name == "tuple")
            {
                const auto * arguments_ast = tuple_ast->arguments->as<ASTExpressionList>();
                if (arguments_ast)
                    fields_count = arguments_ast->children.size();
                else
                    fields_count = 0;
            }
            else
                return false;
        }
        else
        {
            return false;
        }

        partition->setPartitionValue(value);
        partition->fields_count = fields_count;
    }

    node = partition;
    return true;
}

}