PLSQL: using subquery in if-statement error PLS-00405

问题

I'm getting error pls-00405 when I try to run this code:

BEGIN
  IF :P10_KAART_CODE IN (SELECT KAART_CODE FROM CADEAUKAART) THEN
     RETURN TRUE;
  ELSE
    RETURN FALSE;
  END IF;
END;

There are some similar questions about this but couldn't find a solution for this simple code. Is there another way of writing this without facing a error?

回答1:

You may try a cursor, alternatively :

DECLARE
  v_flag  boolean := FALSE;  
BEGIN
 FOR c IN ( SELECT KAART_CODE FROM CADEAUKAART )
 LOOP
   IF :P10_KAART_CODE = c.KAART_CODE THEN
     v_flag := TRUE;
     EXIT;
   END IF;
  EXIT WHEN NO_DATA_FOUND;
 END LOOP;
     RETURN v_flag;
END;

By your way using a select statement is not allowed, you might list all the members for the returning values of KAART_CODE such as

IF :P10_KAART_CODE IN ('aAA','BBb','ccC'..) THEN

but which is not preferable and nice to list all matching values .

回答2:

PL/SQL doesn't support embedded SQL in if statements. So you'll need to rewrite your code like this:

create or replace function validate_kaart_code 
    (P10_KAART_CODE in CADEAUKAART.KAART_CODE%type)
    return boolean
is
    rv boolean;
    l_code CADEAUKAART.KAART_CODE%type;
BEGIN
    begin
        SELECT KAART_CODE into l_code
        FROM CADEAUKAART
        where KAART_CODE =:P10_KAART_CODE 
        and rownum = 1 -- only necessary if KAART_CODE is not unique
        ;
        rv := TRUE;
    exception
        when no_data_found then
            rv := FALSE;
    end;
    RETURN rv;
END;

I have attempted to reconstruct your whole functionality from the snippet you posted. If this isn't what you intended and you can't convert it to fit your needs please provide more details.

回答3:

I'd move the condition to the query itself, and catch a NO_DATA_FOUND exception:

BEGIN
    SELECT * FROM CADEAUKAART WHERE kaart_code = :P10_KAART_CODE;
    RETURN TRUE;
EXCEPTION  WHEN NO_DATA_FOUND THEN
    RETURN FALSE;
END;

回答4:

One more way:

CREATE OR REPLACE FUNCTION IS_KAART_CODE_VALID(pinKAART_CODE IN CADEAUKAART.KAART_CODE%TYPE)
   RETURN BOOLEAN
IS
  nCount  NUMBER;
BEGIN
  SELECT COUNT(*)
    INTO nCount
    FROM CADEAUKAART
    WHERE KAART_CODE = pinKAART_CODE ;

  RETURN CASE
           WHEN nCount > 0 THEN
             TRUE
           ELSE
             FALSE
         END;
END IS_KAART_CODE_VALID;

来源：https://stackoverflow.com/questions/52346437/plsql-using-subquery-in-if-statement-error-pls-00405

标签

sql

Oracle

if-statement

plsql

syntax-error