ClickHouse/src/Functions/currentDatabase.cpp

61 lines
1.4 KiB
C++
Raw Normal View History

2021-05-17 07:30:42 +00:00
#include <Functions/IFunction.h>
#include <Functions/FunctionFactory.h>
#include <Interpreters/Context.h>
#include <DataTypes/DataTypeString.h>
2019-10-04 17:46:36 +00:00
#include <Core/Field.h>
namespace DB
{
2020-09-07 18:00:37 +00:00
namespace
{
class FunctionCurrentDatabase : public IFunction
{
const String db_name;
public:
static constexpr auto name = "currentDatabase";
2021-06-01 12:20:52 +00:00
static FunctionPtr create(ContextPtr context)
{
return std::make_shared<FunctionCurrentDatabase>(context->getCurrentDatabase());
}
2019-08-03 11:02:40 +00:00
explicit FunctionCurrentDatabase(const String & db_name_) : db_name{db_name_}
{
}
String getName() const override
{
return name;
}
size_t getNumberOfArguments() const override
{
return 0;
}
DataTypePtr getReturnTypeImpl(const DataTypes & /*arguments*/) const override
{
return std::make_shared<DataTypeString>();
}
bool isDeterministic() const override { return false; }
2021-06-22 16:21:23 +00:00
bool isSuitableForShortCircuitArgumentsExecution(const DataTypesWithConstInfo & /*arguments*/) const override { return false; }
ColumnPtr executeImpl(const ColumnsWithTypeAndName &, const DataTypePtr &, size_t input_rows_count) const override
{
2020-10-17 16:48:53 +00:00
return DataTypeString().createColumnConst(input_rows_count, db_name);
}
};
2020-09-07 18:00:37 +00:00
}
REGISTER_FUNCTION(CurrentDatabase)
{
factory.registerFunction<FunctionCurrentDatabase>();
factory.registerAlias("DATABASE", "currentDatabase", FunctionFactory::CaseInsensitive);
}
}