Function - User Defined Functions (UDF)

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User-defined Functions (UDFs) is a function provided by a developer and behave as a built-in function. It gives to the developer the possibility to enhance the function possibilities of an application (generally a query language).

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Example

For a database:

• Scalar functions

SELECT myfunc(r.a, r.b)
WHERE yourfunc(r.c, r.d) < 5

• Aggregate functions

SELECT x, concat(r.s) M
GROUP BY x

• Table functions

SELECT W FROM tablefunc(a,b)