Question

I keep getting this syntax error but can’t find anything wrong with it when comparing to other examples.

if EXISTS (select 1 from City where name = 'Perth')
THEN  Print 'Record exits - Update'
ELSE  Print 'Record doesn''t exist - Insert' 

I find error:

#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
1 from City where name = 'Perth') THEN Print 'Record e' at line 1

I get this both on zend cloud and normal phpmyadmin mysql 5

Answer 1

That isn’t actually a valid MySQL query. It looks like you are trying to mix together SQL with how you want to display output based on the whether the query exists or not. You can use this to return whether or not Perth exists in SQL:

SELECT EXISTS(SELECT 1 FROM City WHERE name = 'Perth')

This will return 1 or 0, which you can then parse with your server-side scripts. The reason it is giving you a syntax error is because MySQL IF statements take the form IF(condition, <action if true>, <action if false>), with no use of THEN or ELSE (as is common in programming languages). Also, MySQL doesn’t have an explicit PRINT statement, but you could use SELECT to somewhat accomplish what you want above (note that we can remove EXISTS as False will be implied if the result returns nothing):

SELECT IF(
      (SELECT 1 FROM City WHERE name = 'Perth'),
      (SELECT 'Record exists - update'),
      (SELECT 'Record does not exist - Insert')
)