MySQL Stored Procedure - increment a variable - mysql

Question

Why is my stored procedure erroring on the last two lines. Am i missing something? I am trying to write something that takes my basis name and creates a variable that increments it by 1 and continues until it hits 150. I know how to do this in Microsft SQL which might be where my syntax errors are coming from. Thanks.
USE repo;
DELIMITER $$
Create DEFINER = 'root' # 'localhost' procedure csvOutput()
BEGIN DECLARE basis_name int; SET #basis_name = 0;
if basis_name < 150 then
set basis_name = basis_name + 1;
SELECT *
FROM
(SELECT
'cbt.component',
'fl.input_flow',
'ft.flow',
'Function_ID',
'sf.subfunction',
'fl.output_flow',
'ft2.flow',
'# of times it appears',
'sf.tier'
UNION ALL (SELECT
cbt.component,
fl.input_flow,
ft.flow,
sf.id AS 'Function ID',
sf.subfunction,
fl.output_flow,
ft2.flow,
COUNT(a.name) AS '# of times it appears',
sf.tier
FROM
artifact a, function fu, flow fl, flow_type ft, subfunction_type sf, flow_type ft2, comp_basis_type cbt
WHERE
a.id = fu.describes_artifact
AND fu.id = fl.describes_function
AND fl.input_flow = ft.id
AND fl.output_flow = ft2.id
AND fu.subfunction_type = sf.id
AND a.basis_name = 115
AND fu.supporting = 0
AND a.basis_name = cbt.id
AND sf.tier >= 3
GROUP BY fl.input_flow
ORDER BY COUNT(fu.id) DESC)) resulting_set INTO OUTFILE 'C:/ProgramData/MySQL/MySQL Server 5.7/Uploads/test4.csv' FIELDS ENCLOSED BY '"' TERMINATED BY ',' ESCAPED BY '"' LINES TERMINATED BY '';
END$$
Delimiter;

Answer 1

I tested your statement. For future reference, when you ask about an error on Stack Overflow, please include the error.
This is the error I got from testing:
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DECLARE basis_name int; SET #basis_name = 0;
I see the problem, it's actually on this line:
USE repo; DELIMITER $$ Create DEFINER = 'root' # 'localhost' procedure csvOutput()
Keep in mind that DELIMITER sets the statement delimiter to all of the following text until end of line. So you have set the delimiter not to $$, but to the entire string: $$ Create DEFINER = 'root' # 'localhost' procedure csvOutput()
The error reports some problem with DECLARE because it's trying to start a new statement, not part of the procedure. BEGIN TRANSACTION is a legal statement, but other than that, BEGIN cannot be used on its own in MySQL. So BEGIN DECLARE... caused MySQL to say, "whoah, that's not what I expect you to add after BEGIN!"
Just add a newline after DELIMITER $$
Also note that you must not use a semicolon after the DELIMITER statement because that will become part of your statement terminator too. How else could you set the delimiter back to ;?
Another issue that would help you in the future, but it is not the root cause of the error you asked about:
In MySQL, basis_name and #basis_name are two different variables.
Variables declared with DECLARE within a procedure don't have the # prefix. You use them without the prefix when you declare them and when you use them. These variables are local to the stored procedure where they are declared.
Variables with the # prefix don't need to be declared. These are called "user-defined variables". You can create them merely by assigning a value to an identifier. You must always use the # prefix when you reference these variables. These variables are not local to the procedure where you set them. They retain their value in your current session after the procedure has finished. You can set their value and read their value with simple SQL statements outside a procedure.
This is a common issue on which Microsoft users get confused when moving to MySQL.