ClickHouse/dbms/src/Interpreters/DatabaseAndTableWithAlias.h
2019-03-11 17:01:45 +03:00

50 lines
1.7 KiB
C++

#pragma once
#include <Core/Names.h>
#include <Core/Types.h>
#include <Parsers/IAST_fwd.h>
#include <memory>
#include <optional>
namespace DB
{
class ASTSelectQuery;
class ASTIdentifier;
struct ASTTableExpression;
class Context;
/// Extracts database name (and/or alias) from table expression or identifier
struct DatabaseAndTableWithAlias
{
String database;
String table;
String alias;
DatabaseAndTableWithAlias() = default;
DatabaseAndTableWithAlias(const ASTPtr & identifier_node, const String & current_database = "");
DatabaseAndTableWithAlias(const ASTIdentifier & identifier, const String & current_database = "");
DatabaseAndTableWithAlias(const ASTTableExpression & table_expression, const String & current_database = "");
/// "alias." or "table." if alias is empty
String getQualifiedNamePrefix(bool with_dot = true) const;
/// Check if it satisfies another db_table name. @note opterion is not symmetric.
bool satisfies(const DatabaseAndTableWithAlias & table, bool table_may_be_an_alias);
};
using TableWithColumnNames = std::pair<DatabaseAndTableWithAlias, Names>;
std::vector<DatabaseAndTableWithAlias> getDatabaseAndTables(const ASTSelectQuery & select_query, const String & current_database);
std::optional<DatabaseAndTableWithAlias> getDatabaseAndTable(const ASTSelectQuery & select, size_t table_number);
std::vector<TableWithColumnNames> getDatabaseAndTablesWithColumnNames(const ASTSelectQuery & select_query, const Context & context);
std::vector<const ASTTableExpression *> getSelectTablesExpression(const ASTSelectQuery & select_query);
ASTPtr extractTableExpression(const ASTSelectQuery & select, size_t table_number);
}