Hi, All
Recently, I try to upgrade flink from 1.8.2 to 1.10, but i meet some problem
about function. In 1.8.2, there are just Built-In function and User-defined
Functions, but in 1.10, there are 4 categories of funtions.
I defined a function which named JSON_VALUE in my system, it doesn’t exist in
1.8.2, but present to 1.10.0. of course i use it in sql, something like 'select
JSON_VALUE(string, string) from table1’, no category or database. the problem
is in 1.10.0, my function will be recognized as SqlJsonValueFunction, and args
not match, so my sql is wrong.
I read document about Ambiguous Function Reference, In my understanding, my
function will be registered as temporary system function, and it should be
chosen first. isn’t it? I try to debug it, and find some information:
First, sql will be parsed by ParseImpl, and JSON_VALUE will be parsed as
SqlBasicCall, operator is SqlJsonValueFunction, it’s belonged to SYSTEM catalog
and the kind is OTHER_FUNCTION. Then,SqlUtil.lookupRoutine will not find this
SqlFunction, because it not in BasicOperatorTable. my function
inFunctionCatalog, butSqlJsonValueFunctionbelonged to SYSTEM, not belong
toUSER_DEFINED, so program will not search it in FunctionCatalog.
How can i solve this problem without modifying sql and function name? my
program can choose flink version and have many sql jobs, so i don’t wish to
modify sql and function name.
Thansk.
