ClickHouse/dbms/src/Parsers/ParserAlterQuery.cpp

#include <Parsers/ParserAlterQuery.h>
#include <Parsers/CommonParsers.h>
#include <Parsers/ExpressionElementParsers.h>
#include <Parsers/ParserCreateQuery.h>
#include <Parsers/ASTIdentifier.h>
#include <Parsers/ExpressionElementParsers.h>
#include <Parsers/ASTAlterQuery.h>
#include <Parsers/ASTLiteral.h>

namespace DB
{

bool ParserAlterQuery::parseImpl(Pos & pos, Pos end, ASTPtr & node, Pos & max_parsed_pos, Expected & expected)
{
    Pos begin = pos;

    ParserString s_alter(     "ALTER", true, true);
    ParserString s_table(     "TABLE", true, true);
    ParserString s_add(       "ADD", true, true);
    ParserString s_column(    "COLUMN", true, true);
    ParserString s_after(     "AFTER", true, true);
    ParserString s_modify(    "MODIFY", true, true);
    ParserString s_primary(   "PRIMARY", true, true);
    ParserString s_key(       "KEY", true, true);
    ParserString s_reshard(   "RESHARD", true, true);
    ParserString s_drop(      "DROP", true, true);
    ParserString s_detach(    "DETACH", true, true);
    ParserString s_attach(    "ATTACH", true, true);
    ParserString s_fetch(     "FETCH", true, true);
    ParserString s_freeze(    "FREEZE", true, true);
    ParserString s_part(      "PART", true, true);
    ParserString s_partition( "PARTITION", true, true);
    ParserString s_from(      "FROM", true, true);
    ParserString s_copy(      "COPY", true, true);
    ParserString s_to(        "TO", true, true);
    ParserString s_using(     "USING", true, true);
    ParserString s_coordinate("COORDINATE", true, true);
    ParserString s_with(      "WITH", true, true);
    ParserString s_name(      "NAME", true, true);

    ParserString s_dot(".");
    ParserString s_comma(",");
    ParserString s_doubledot("..");

    ParserWhiteSpaceOrComments ws;

    ParserIdentifier table_parser;
    ParserCompoundIdentifier parser_name;
    ParserCompoundColumnDeclaration parser_col_decl;
    ParserLiteral parser_literal;
    ParserUnsignedInteger parser_uint;
    ParserStringLiteral parser_string_literal;

    ASTPtr table;
    ASTPtr database;
    ASTPtr col_type;
    ASTPtr col_after;
    ASTPtr col_drop;

    auto query = std::make_shared<ASTAlterQuery>();

    ws.ignore(pos, end);
    if (!s_alter.ignore(pos, end, max_parsed_pos, expected))
        return false;

    ws.ignore(pos, end);
    if (!s_table.ignore(pos, end, max_parsed_pos, expected))
        return false;

    ws.ignore(pos, end);

    if (!table_parser.parse(pos, end, database, max_parsed_pos, expected))
        return false;

    /// Parse [db].name
    if (s_dot.ignore(pos, end))
    {
        if (!table_parser.parse(pos, end, table, max_parsed_pos, expected))
            return false;

        query->table = typeid_cast<ASTIdentifier &>(*table).name;
        query->database = typeid_cast<ASTIdentifier &>(*database).name;
    }
    else
    {
        table = database;
        query->table = typeid_cast<ASTIdentifier &>(*table).name;
    }

    bool parsing_finished = false;
    do
    {
        ASTAlterQuery::Parameters params;
        ws.ignore(pos, end);

        if (s_add.ignore(pos, end, max_parsed_pos, expected))
        {
            ws.ignore(pos, end);
            if (!s_column.ignore(pos, end, max_parsed_pos, expected))
                return false;
            ws.ignore(pos, end);

            if (!parser_col_decl.parse(pos, end, params.col_decl, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);
            if (s_after.ignore(pos, end, max_parsed_pos, expected))
            {
                ws.ignore(pos, end);

                if(!parser_name.parse(pos, end, params.column, max_parsed_pos, expected))
                    return false;
            }

            params.type = ASTAlterQuery::ADD_COLUMN;
        }
        else if (s_drop.ignore(pos, end, max_parsed_pos, expected))
        {
            ws.ignore(pos, end);

            if (s_partition.ignore(pos, end, max_parsed_pos, expected))
            {
                ws.ignore(pos, end);

                if (!parser_literal.parse(pos, end, params.partition, max_parsed_pos, expected))
                    return false;

                params.type = ASTAlterQuery::DROP_PARTITION;
            }
            else if (s_column.ignore(pos, end, max_parsed_pos, expected))
            {
                ws.ignore(pos, end);

                if (!parser_name.parse(pos, end, params.column, max_parsed_pos, expected))
                    return false;

                params.type = ASTAlterQuery::DROP_COLUMN;
                params.detach = false;

                if (s_from.ignore(pos, end, max_parsed_pos, expected))
                {
                    ws.ignore(pos, end);

                    if (!s_partition.ignore(pos, end, max_parsed_pos, expected))
                        return false;
                    ws.ignore(pos, end);

                    if (!parser_literal.parse(pos, end, params.partition, max_parsed_pos, expected))
                        return false;
                }
            }
            else
                return false;
        }
        else if (s_detach.ignore(pos, end, max_parsed_pos, expected))
        {
            ws.ignore(pos, end);

            if (!s_partition.ignore(pos, end, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            if (!parser_literal.parse(pos, end, params.partition, max_parsed_pos, expected))
                return false;

            params.type = ASTAlterQuery::DROP_PARTITION;
            params.detach = true;
        }
        else if (s_attach.ignore(pos, end, max_parsed_pos, expected))
        {
            ws.ignore(pos, end);

            if (s_part.ignore(pos, end, max_parsed_pos, expected))
                params.part = true;
            else if (!s_partition.ignore(pos, end, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            if (!parser_literal.parse(pos, end, params.partition, max_parsed_pos, expected))
                return false;

            params.type = ASTAlterQuery::ATTACH_PARTITION;
        }
        else if (s_fetch.ignore(pos, end, max_parsed_pos, expected))
        {
            ws.ignore(pos, end);

            if (!s_partition.ignore(pos, end, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            if (!parser_literal.parse(pos, end, params.partition, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            if (!s_from.ignore(pos, end, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            ASTPtr ast_from;
            if (!parser_string_literal.parse(pos, end, ast_from, max_parsed_pos, expected))
                return false;

            params.from = typeid_cast<const ASTLiteral &>(*ast_from).value.get<const String &>();
            params.type = ASTAlterQuery::FETCH_PARTITION;
        }
        else if (s_freeze.ignore(pos, end, max_parsed_pos, expected))
        {
            ws.ignore(pos, end);

            if (!s_partition.ignore(pos, end, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            if (!parser_literal.parse(pos, end, params.partition, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            /// WITH NAME 'name' - place local backup to directory with specified name
            if (s_with.ignore(pos, end, max_parsed_pos, expected))
            {
                ws.ignore(pos, end);

                if (!s_name.ignore(pos, end, max_parsed_pos, expected))
                    return false;

                ws.ignore(pos, end);

                ASTPtr ast_with_name;
                if (!parser_string_literal.parse(pos, end, ast_with_name, max_parsed_pos, expected))
                    return false;

                params.with_name = typeid_cast<const ASTLiteral &>(*ast_with_name).value.get<const String &>();

                ws.ignore(pos, end);
            }

            params.type = ASTAlterQuery::FREEZE_PARTITION;
        }
        else if (s_modify.ignore(pos, end, max_parsed_pos, expected))
        {
            ws.ignore(pos, end);

            if (s_column.ignore(pos, end, max_parsed_pos, expected))
            {
                ws.ignore(pos, end);

                if (!parser_col_decl.parse(pos, end, params.col_decl, max_parsed_pos, expected))
                    return false;

                ws.ignore(pos, end);

                params.type = ASTAlterQuery::MODIFY_COLUMN;
            }
            else if (s_primary.ignore(pos, end, max_parsed_pos, expected))
            {
                ws.ignore(pos, end);

                if (!s_key.ignore(pos, end, max_parsed_pos, expected))
                    return false;

                ws.ignore(pos, end);

                if (!ParserString("(").ignore(pos, end, max_parsed_pos, expected))
                    return false;

                ws.ignore(pos, end);

                if (!ParserNotEmptyExpressionList(false).parse(pos, end, params.primary_key, max_parsed_pos, expected))
                    return false;

                ws.ignore(pos, end);

                if (!ParserString(")").ignore(pos, end, max_parsed_pos, expected))
                    return false;

                ws.ignore(pos, end);

                params.type = ASTAlterQuery::MODIFY_PRIMARY_KEY;
            }
            else
                return false;
        }
        else if (s_reshard.ignore(pos, end, max_parsed_pos, expected))
        {
            ParserList weighted_zookeeper_paths_p(std::make_unique<ParserWeightedZooKeeperPath>(), std::make_unique<ParserString>(","), false);
            ParserExpressionWithOptionalAlias parser_sharding_key_expr(false);
            ParserStringLiteral parser_coordinator;

            ws.ignore(pos, end);

            if (s_copy.ignore(pos, end, max_parsed_pos, expected))
                params.do_copy = true;

            ws.ignore(pos, end);

            if (s_partition.ignore(pos, end, max_parsed_pos, expected))
            {
                ws.ignore(pos, end);

                if (!parser_uint.parse(pos, end, params.partition, max_parsed_pos, expected))
                    return false;

                ws.ignore(pos, end);

                if (s_doubledot.ignore(pos, end, max_parsed_pos, expected))
                {
                    ws.ignore(pos, end);

                    if (!parser_uint.parse(pos, end, params.last_partition, max_parsed_pos, expected))
                        return false;
                }
            }

            ws.ignore(pos, end);

            if (!s_to.ignore(pos, end, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            if (!weighted_zookeeper_paths_p.parse(pos, end, params.weighted_zookeeper_paths, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            if (!s_using.ignore(pos, end, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            if (!parser_sharding_key_expr.parse(pos, end, params.sharding_key_expr, max_parsed_pos, expected))
                return false;

            ws.ignore(pos, end);

            if (s_coordinate.ignore(pos, end, max_parsed_pos, expected))
            {
                ws.ignore(pos, end);

                if (!s_with.ignore(pos, end, max_parsed_pos, expected))
                    return false;

                ws.ignore(pos, end);

                if (!parser_coordinator.parse(pos, end, params.coordinator, max_parsed_pos, expected))
                    return false;

                ws.ignore(pos, end);
            }

            params.type = ASTAlterQuery::RESHARD_PARTITION;
        }
        else
            return false;

        ws.ignore(pos, end);

        if (!s_comma.ignore(pos, end, max_parsed_pos, expected))
        {
            ws.ignore(pos, end);
            parsing_finished = true;
        }

        query->addParameters(params);
    }
    while (!parsing_finished);

    query->range = StringRange(begin, end);
    node = query;

    return true;
}
}