ClickHouse/src/TableFunctions/TableFunctionMySQL.cpp
2022-05-04 12:01:29 +02:00

96 lines
3.0 KiB
C++

#include "config_core.h"
#if USE_MYSQL
#include <Databases/MySQL/FetchTablesColumnsList.h>
#include <Processors/Sources/MySQLSource.h>
#include <Interpreters/Context.h>
#include <Interpreters/evaluateConstantExpression.h>
#include <Parsers/ASTFunction.h>
#include <Storages/StorageMySQL.h>
#include <Storages/MySQL/MySQLSettings.h>
#include <Storages/MySQL/MySQLHelpers.h>
#include <TableFunctions/ITableFunction.h>
#include <TableFunctions/TableFunctionFactory.h>
#include <TableFunctions/TableFunctionMySQL.h>
#include <Common/Exception.h>
#include <Common/parseAddress.h>
#include <Common/quoteString.h>
#include "registerTableFunctions.h"
#include <Databases/MySQL/DatabaseMySQL.h> // for fetchTablesColumnsList
#include <Common/parseRemoteDescription.h>
namespace DB
{
namespace ErrorCodes
{
extern const int LOGICAL_ERROR;
extern const int UNKNOWN_TABLE;
}
void TableFunctionMySQL::parseArguments(const ASTPtr & ast_function, ContextPtr context)
{
const auto & args_func = ast_function->as<ASTFunction &>();
if (!args_func.arguments)
throw Exception("Table function 'mysql' must have arguments.", ErrorCodes::LOGICAL_ERROR);
MySQLSettings mysql_settings;
configuration = StorageMySQL::getConfiguration(args_func.arguments->children, context, 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;
pool.emplace(createMySQLPoolWithFailover(*configuration, mysql_settings));
}
ColumnsDescription TableFunctionMySQL::getActualTableStructure(ContextPtr context) const
{
const auto & settings = context->getSettingsRef();
const auto tables_and_columns = fetchTablesColumnsList(*pool, configuration->database, {configuration->table}, settings, settings.mysql_datatypes_support_level);
const auto columns = tables_and_columns.find(configuration->table);
if (columns == tables_and_columns.end())
throw Exception("MySQL table " + (configuration->database.empty() ? "" : (backQuote(configuration->database) + "."))
+ backQuote(configuration->table) + " doesn't exist.", ErrorCodes::UNKNOWN_TABLE);
return columns->second;
}
StoragePtr TableFunctionMySQL::executeImpl(
const ASTPtr & /*ast_function*/,
ContextPtr context,
const std::string & table_name,
ColumnsDescription /*cached_columns*/) const
{
auto columns = getActualTableStructure(context);
auto res = std::make_shared<StorageMySQL>(
StorageID(getDatabaseName(), table_name),
std::move(*pool),
configuration->database,
configuration->table,
configuration->replace_query,
configuration->on_duplicate_clause,
columns,
ConstraintsDescription{},
String{},
context,
MySQLSettings{});
pool.reset();
res->startup();
return res;
}
void registerTableFunctionMySQL(TableFunctionFactory & factory)
{
factory.registerFunction<TableFunctionMySQL>();
}
}
#endif