ClickHouse/src/TableFunctions/TableFunctionMySQL.cpp
2023-11-09 23:05:55 +01:00

128 lines
3.6 KiB
C++

#include "config.h"
#if USE_MYSQL
#include <Storages/StorageMySQL.h>
#include <Processors/Sources/MySQLSource.h>
#include <Interpreters/Context.h>
#include <Parsers/ASTFunction.h>
#include <Storages/MySQL/MySQLSettings.h>
#include <Storages/MySQL/MySQLHelpers.h>
#include <TableFunctions/ITableFunction.h>
#include <TableFunctions/TableFunctionFactory.h>
#include <Common/Exception.h>
#include <Common/parseAddress.h>
#include <Common/quoteString.h>
#include "registerTableFunctions.h"
#include <Databases/MySQL/DatabaseMySQL.h>
#include <Common/parseRemoteDescription.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
}
namespace
{
/* mysql ('host:port', database, table, user, password) - creates a temporary StorageMySQL.
* The structure of the table is taken from the mysql query DESCRIBE table.
* If there is no such table, an exception is thrown.
*/
class TableFunctionMySQL : public ITableFunction
{
public:
static constexpr auto name = "mysql";
std::string getName() const override
{
return name;
}
private:
StoragePtr executeImpl(const ASTPtr & ast_function, ContextPtr context, const std::string & table_name, ColumnsDescription cached_columns, bool is_insert_query) const override;
const char * getStorageTypeName() const override { return "MySQL"; }
ColumnsDescription getActualTableStructure(ContextPtr context, bool is_insert_query) const override;
void parseArguments(const ASTPtr & ast_function, ContextPtr context) override;
mutable std::optional<mysqlxx::PoolWithFailover> pool;
std::optional<StorageMySQL::Configuration> configuration;
};
void TableFunctionMySQL::parseArguments(const ASTPtr & ast_function, ContextPtr context)
{
const auto & args_func = ast_function->as<ASTFunction &>();
if (!args_func.arguments)
throw Exception(ErrorCodes::LOGICAL_ERROR, "Table function 'mysql' must have arguments.");
auto & args = args_func.arguments->children;
MySQLSettings mysql_settings;
const auto & settings = context->getSettingsRef();
mysql_settings.connect_timeout = settings.external_storage_connect_timeout_sec;
mysql_settings.read_write_timeout = settings.external_storage_rw_timeout_sec;
for (auto * it = args.begin(); it != args.end(); ++it)
{
const ASTSetQuery * settings_ast = (*it)->as<ASTSetQuery>();
if (settings_ast)
{
mysql_settings.loadFromQuery(*settings_ast);
args.erase(it);
break;
}
}
configuration = StorageMySQL::getConfiguration(args, context, mysql_settings);
pool.emplace(createMySQLPoolWithFailover(*configuration, mysql_settings));
}
ColumnsDescription TableFunctionMySQL::getActualTableStructure(ContextPtr context, bool /*is_insert_query*/) const
{
return StorageMySQL::getTableStructureFromData(*pool, configuration->database, configuration->table, context);
}
StoragePtr TableFunctionMySQL::executeImpl(
const ASTPtr & /*ast_function*/,
ContextPtr context,
const std::string & table_name,
ColumnsDescription cached_columns,
bool /*is_insert_query*/) const
{
auto res = std::make_shared<StorageMySQL>(
StorageID(getDatabaseName(), table_name),
std::move(*pool),
configuration->database,
configuration->table,
configuration->replace_query,
configuration->on_duplicate_clause,
cached_columns,
ConstraintsDescription{},
String{},
context,
MySQLSettings{});
pool.reset();
res->startup();
return res;
}
}
void registerTableFunctionMySQL(TableFunctionFactory & factory)
{
factory.registerFunction<TableFunctionMySQL>();
}
}
#endif