Plsql function error in computation

Question

Hi Friends,
I have the below plsql function which is throwing error.
The below function is written in Apex, so kindly let me know how to resolve this error
The below query checks the existing value and if null assigns a value by select statement. else will assign it back to the variable. I am not getting how to set the value dynamically using the select statement
Function:
BEGIN
IF
:P1_VARIABLE_NAME IS NULL THEN :P1_VARIABLE_NAME:=select .... from .... (which returns a string value)
ELSE
:P1_VARIABLE_NAME
END
END
Error:
Encountered the symbol "SELECT" when expecting one of the following: ( - + case mod new not null avg count current exists max min prior sql stddev sum variance execute forall merge time timestamp interval date pipe

Answer 1

Hi Kiran,
I followed the query you mentioned and I am now getting the follwing below error:
ORA-06550: line 7, column 3: PLS-00110: bind variable 'P1_VARIABLE_NAME' not allowed in this context ORA-06550: line 9, column 1: PLS-00103: Encountered the symbol "END" when expecting one of the following: ; The symbol ";" was substituted for "END" to continue.
Note that I am using the PLSQL function block to fetch the data in the computation section of Apex.