ClickHouse/src/Interpreters/castColumn.cpp
2020-06-18 13:18:28 +03:00

43 lines
1.1 KiB
C++

#include <Core/Field.h>
#include <Interpreters/castColumn.h>
#include <Interpreters/ExpressionActions.h>
#include <DataTypes/DataTypeString.h>
#include <Functions/IFunctionAdaptors.h>
#include <Functions/FunctionsConversion.h>
namespace DB
{
ColumnPtr castColumn(const ColumnWithTypeAndName & arg, const DataTypePtr & type)
{
if (arg.type->equals(*type))
return arg.column;
Block temporary_block
{
arg,
{
DataTypeString().createColumnConst(arg.column->size(), type->getName()),
std::make_shared<DataTypeString>(),
""
},
{
nullptr,
type,
""
}
};
FunctionOverloadResolverPtr func_builder_cast =
std::make_shared<FunctionOverloadResolverAdaptor>(CastOverloadResolver::createImpl(false));
ColumnsWithTypeAndName arguments{ temporary_block.getByPosition(0), temporary_block.getByPosition(1) };
auto func_cast = func_builder_cast->build(arguments);
func_cast->execute(temporary_block, {0, 1}, 2, arg.column->size());
return temporary_block.getByPosition(2).column;
}
}