- call(f: Union[str, pyflink.table.udf.UserDefinedFunctionWrapper], *args) pyflink.table.expression.Expression [source]#
The first parameter f could be a str or a Python user-defined function.
When it is str, this is a call to a function that will be looked up in a catalog. There are two kinds of functions:
System functions - which are identified with one part names
- Catalog functions - which are identified always with three parts names
(catalog, database, function)
Moreover each function can either be a temporary function or permanent one (which is stored in an external catalog).
Based on that two properties the resolution order for looking up a function based on the provided function_name is following:
Temporary system function
Temporary catalog function
f – the path of the function or the Python user-defined function.
args – parameters of the user-defined function.
New in version 1.12.0.