IF NOT EXIST NOT WORKING - mysql

Question

IF NOT EXISTS(SELECT * FROM `user` WHERE `name`='Rutvij' AND `lang`='python')
BEGIN
INSERT INTO `user` VALUES ('Rutvij', 'python', 25)
END
ELSE
BEGIN
UPDATE user SET `name`='Kanzaria' WHERE `name`='Rutvij'
END
I am trying the above query in phpmyadmin sql area. I am using xampp. It is throwing error stating that
1064 - 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 'IF EXISTS(SELECT * FROM user)
SELECT name FROM use' at line 1
I have also tried the below code
IF NOT EXISTS(SELECT * FROM user WHERE name='Rutvij' AND lang='python')
BEGIN
INSERT INTO user VALUES ('Rutvij', 'python', 25)
END
ELSE
BEGIN
INSERT INTO user VALUES ('Kanzaria', 'python', 25)
END
Struggling for so long. Kindly help. Thanks!!

Answer 1

MySQL doesn't permit if logic, unless you are in a programming block (stored procedure, trigger, or function).
Fortunately, you can do the same with WHERE logic:
INSERT INTO user
SELECT 'Rutvij', 'python', 25
FROM DUAL
WHERE NOT EXISTS (SELECT 1 FROM user WHERE name = 'Rutvij' AND lang = 'python')
UNION ALL
SELECT 'Kanzaria', 'python', 25
FROM DUAL
WHERE EXISTS (SELECT 1 FROM user WHERE name = 'Rutvij' AND lang = 'python');
MySQL should process the SELECT before the INSERT, so only one row should be inserted.
Or, you can do this as two INSERTs but in the opposite order:
INSERT INTO user
SELECT 'Kanzaria', 'python', 25
FROM DUAL
WHERE EXISTS (SELECT 1 FROM user WHERE name = 'Rutvij' AND lang = 'python');
INSERT INTO user
SELECT 'Rutvij', 'python', 25
FROM DUAL
WHERE NOT EXISTS (SELECT 1 FROM user WHERE name = 'Rutvij' AND lang = 'python');

Answer 2

This is not a query, this would be an sql script with control flow logic, which is not allowed in mysql outside stored programs (procedures, functions, triggers). Even if you encapsulated the above code into a stored procedure it would not work because exist / not exists can only be used in subqueries.
I would do the following:
Create a stored procedure
Declare an integer variable
Using select into fetch the count of rows where name='Rutvij' AND lang='python' into your variable.
Use the if statement to do the insertion based on the number of records.