Dynamic Oracle Procedure - issue with structure - sql

Question

I seem to be having some issues around creating a stored procedure and I simply cannot see where the issue lies. I am relatively new to Oracle.
I have a table of unknown length. What I have done is I created a stored procedure that will create a table to the width of the row count of the table where I am getting my values from. i.e. if the table has 10 values, the code will create a new table 10 columns wide, etc.
I have managed to get the initial code working, but now I am trying to add some additional logic without success.
My logic that I am trying to accomplish is as such:
IF TABLE DOES NOT EXIST - CREATE IT
IF TABLE EXSITS - SIMPLY INSERT INTO IT
I have not created the code for the INSERT part yet as I cannot get the first part to work. Everything was working fine until I added the count and IF statement.
CREATE OR REPLACE PROCEDURE "MDWPROD"."WORKFLOW_VAR_PIVOT" IS
v_sql varchar2(32767);
-- for the first run ofthe procedure, we need to create the table
DECLARE var_count INT;
SELECT
COUNT(*)
INTO
var_count
FROM
all_tables
WHERE
OWNER = 'MDWPROD'
AND TABLE_NAME = 'RBI_PROCESSVARIABLE_WK';
-- if var_count = 0 then the table does not exists, create it, otherwise proceed with other logic
IF var_count = 0 THEN
-- cursor to find out the maximum number of projected columns required
CURSOR cur_proj_test IS
SELECT DISTINCT
ID,
VARIABLE_REPORT_LBL
FROM
MDWPROD.RBI_VARIABLETYPE_DM
ORDER BY
ID;
-- We now loop through the cursor, and build of the SQL string to CREATE and POPULATE the table
BEGIN
v_sql := 'CREATE TABLE MDWPROD.RBI_PROCESSVARIABLE_WK AS SELECT VAR.PROCESS_ID';
FOR i IN cur_proj_test
LOOP
-- dynamically add to the projection for the query
v_sql := v_sql || ',MAX(CASE VT.VARIABLE_REPORT_LBL WHEN ''' || i.VARIABLE_REPORT_LBL || ''' THEN VAR.VALUE ELSE '''' END) AS "' || i.VARIABLE_REPORT_LBL || '"';
END LOOP;
v_sql := v_sql || ' FROM MDWPROD.RBI_VARIABLE_DM VAR INNER JOIN MDWPROD.RBI_VARIABLETYPE_DM VT ON VAR.VARIABLE_TYPE_ID = VT.ID WHERE VAR.CURRENT_IND = ''Y'' GROUP BY VAR.PROCESS_ID order by VAR.PROCESS_ID';
-- Create table and populate it with all the relevant variable values
EXECUTE IMMEDIATE v_sql;
END;
END IF;
END;
Any assistance would be greatly appreciated.
Original working proc:
CREATE OR REPLACE PROCEDURE WORKFLOW_VAR_PIVOT IS
v_sql varchar2(32767);
-- cursor to find out the maximum number of projected columns required
CURSOR cur_proj_test IS
SELECT DISTINCT
ID,
VARIABLE_REPORT_LBL
FROM
MDWPROD.RBI_VARIABLETYPE_DM
ORDER BY
ID;
-- We now loop through the cursor, and build of the SQL string to CREATE and POPULATE the table
BEGIN
v_sql := 'CREATE TABLE MDWPROD.RBI_PROCESSVARIABLE AS SELECT VAR.PROCESS_ID';
FOR i IN cur_proj_test
LOOP
-- dynamically add to the projection for the query
v_sql := v_sql || ',MAX(CASE VT.VARIABLE_REPORT_LBL WHEN ''' || i.VARIABLE_REPORT_LBL || ''' THEN VAR.VALUE ELSE '''' END) AS "' || i.VARIABLE_REPORT_LBL || '"';
END LOOP;
v_sql := v_sql || ' FROM MDWPROD.RBI_VARIABLE_DM VAR INNER JOIN MDWPROD.RBI_VARIABLETYPE_DM VT ON VAR.VARIABLE_TYPE_ID = VT.ID WHERE VAR.CURRENT_IND = ''Y'' GROUP BY VAR.PROCESS_ID order by VAR.PROCESS_ID';
-- un comment this line to print out the entire SQL statement
-- dbms_output.put_line('Dynamic SQL Statement:-' || chr(10) || v_sql || chr(10) || chr(10));
-- DROP TABLE before recreating it
EXECUTE IMMEDIATE 'DROP TABLE MDWPROD.RBI_PROCESSVARIABLE';
-- Create table and populate it with all the relevant variable values
EXECUTE IMMEDIATE v_sql;
END;

Answer 1

There may be other problems (you never stated your exact error), but I can immediately see that the begin keyword is in the wrong place. Your declarations should be at the top, before the begin keyword, and your execution statements should come after.
I moved things around a little. This should get you closer to your goal:
CREATE OR REPLACE PROCEDURE "MDWPROD"."WORKFLOW_VAR_PIVOT" IS
v_sql varchar2(32767);
-- for the first run ofthe procedure, we need to create the table
DECLARE var_count INT;
-- cursor to find out the maximum number of projected columns required
CURSOR cur_proj_test IS
SELECT DISTINCT
ID,
VARIABLE_REPORT_LBL
FROM
MDWPROD.RBI_VARIABLETYPE_DM
ORDER BY
ID;
BEGIN
SELECT
COUNT(*)
INTO
var_count
FROM
all_tables
WHERE
OWNER = 'MDWPROD'
AND TABLE_NAME = 'RBI_PROCESSVARIABLE_WK';
-- if var_count = 0 then the table does not exists, create it, otherwise proceed with other logic
IF var_count = 0 THEN
-- We now loop through the cursor, and build of the SQL string to CREATE and POPULATE the table
v_sql := 'CREATE TABLE MDWPROD.RBI_PROCESSVARIABLE_WK AS SELECT VAR.PROCESS_ID';
FOR i IN cur_proj_test
LOOP
-- dynamically add to the projection for the query
v_sql := v_sql || ',MAX(CASE VT.VARIABLE_REPORT_LBL WHEN ''' || i.VARIABLE_REPORT_LBL || ''' THEN VAR.VALUE ELSE '''' END) AS "' || i.VARIABLE_REPORT_LBL || '"';
END LOOP;
v_sql := v_sql || ' FROM MDWPROD.RBI_VARIABLE_DM VAR INNER JOIN MDWPROD.RBI_VARIABLETYPE_DM VT ON VAR.VARIABLE_TYPE_ID = VT.ID WHERE VAR.CURRENT_IND = ''Y'' GROUP BY VAR.PROCESS_ID order by VAR.PROCESS_ID';
-- Create table and populate it with all the relevant variable values
EXECUTE IMMEDIATE v_sql;
END IF;
END;