Hi, SQL only offers DDL to register function classes, not instances. Such functions must have a default constructor. You can create a class extending your function and calling the super constructor with the respective arguments and then use that class through the DDL.
Best Ingo On Tue, Aug 3, 2021, 19:02 1095193...@qq.com <1095193...@qq.com> wrote: > Hi community, > > For parameterize function, like > > *public* *static* *class* *SubstringFunction* *extends* ScalarFunction *{* > > > > *private* *boolean* endInclusive*;* > > > > *public* *SubstringFunction**(**boolean* endInclusive*)* *{* > > *this.*endInclusive *=* endInclusive*;* > > *}* > > > > *public* String *eval**(*String s*,* Integer begin*,* Integer end*)* *{* > > *return* s*.*substring*(*begin*,* endInclusive *?* end *+* 1 *:* end > *);* > > *}* > > *}* > > we can register this function by pass function instance instead of > function classes. > > *env**.**createTemporarySystemFunction**(**"SubstringFunction"**,* *new* > *SubstringFunction**(true));* > > How to register or create this parameterize function with 'CREATE > FUNTION' statements. > > With standard 'CREATE FUNCTION' statement in Flink doc.[1] > > *CREATE [TEMPORARY|TEMPORARY SYSTEM] FUNCTION * > > * [IF NOT EXISTS] [catalog_name.][db_name.]function_name * > > * AS identifier [LANGUAGE JAVA|SCALA|PYTHON]* > > We can only pass function_name in CREATE FUNCTION statement, is there way > to pass function_instance ( parameterize function ) in this statement. > > > *[1]* > https://ci.apache.org/projects/flink/flink-docs-release-1.13/docs/dev/table/sql/create/#create-function > > > > ------------------------------ > 1095193...@qq.com >