Question

I have a table which has column_id of type varchar2. This table may contain 1, 0 or multiple rows. My business logic depends on each case.

I am trying to fetch the column into an array but i am getting weird error (given my limited knowledge of pl/sql)

  TYPE t_col_id IS TABLE OF TEST_TABLE.COLUMN_ID%TYPE INDEX BY BINARY_INTEGER;
  AR_COL_ID T_COL_ID;

Then i am trying to fetch data into this array

SELECT COLUMN_ID INTO AR_SIM_ID FROM TEST_TABLE WHERE COLUMN_ID = 1;

and i am getting this error

Error(7,3): PL/SQL: SQL Statement ignored
Error(7,25): PLS-00597: expression 'AR_SIM_ID' in the INTO list is of wrong type
Error(7,35): PL/SQL: ORA-00904: : invalid identifier

Is there something that i am missing? My original code would use this array as

BEGIN
   -- FETCH ARRAY QUERY
   IF (AR_SIM_ID.LENGTH = 0) THEN 
      -- BUSINESS LOGIC 1
   ELSE
      -- BUSINESS LOGIC 2
   EXCEPTION
      WHEN NO_DATA_FOUND THEN
         -- BUSINESS LOGIC 3
END;

Answer 1

Instead of using INTO you must use BULK COLLECT INTO:

DECLARE
   TYPE t_col_id IS TABLE OF TEST_TABLE.COLUMN_ID%TYPE INDEX BY BINARY_INTEGER;
   AR_COL_ID T_COL_ID;
BEGIN
   SELECT COLUMN_ID 
     BULK COLLECT INTO AR_SIM_ID 
     FROM TEST_TABLE
    WHERE COLUMN_ID = 1;

   IF AR_SIM_ID.LENGTH = 0 THEN 
      -- BUSINESS LOGIC 1
   ELSE
      -- BUSINESS LOGIC 2
   END IF;

EXCEPTION
   WHEN NO_DATA_FOUND THEN
      -- BUSINESS LOGIC 3
END;

But couldn’t you just use COUNT for this scenario?

DECLARE
   numRows   NUMBER;
BEGIN
   SELECT COUNT(COLUMN_ID)
     INTO numRows
     FROM TEST_TABLE 
    WHERE COLUMN_ID = 1;

   IF numRows = 0 THEN 
      -- BUSINESS LOGIC 1
   ELSE
      -- BUSINESS LOGIC 2, 3, etc...
   END IF;
END;