mysql if function - subquery as a condition [closed]

Question

I believe the following query is self explanatory:

SELECT IF (SELECT COUNT(*) FROM mytable > 0, 'yes', 'no');

Why doesn't it work? And how should I correct it?

Answer 1

If your query is more complex and this is only a reduced problem, I think this is the better solution for you

SELECT IF ( (SELECT COUNT(*) AS counter FROM myTable HAVING counter>0) , 'yes', 'no')

so you can do more complex check (i.e. counter > N or multiple conditions)

Answer 2

It this what you want?

SELECT IF(COUNT(*) > 0, 'yes', 'no') FROM mytable;

---

1:

SELECT
  t1.*,
  (SELECT IF(COUNT(*) > 0, 'yes', 'no') FROM mytable) AS col1
FROM
  table t1;

2:

SELECT
  t1.*,
  t2.*
FROM
  table t1,
  (SELECT IF(COUNT(*) > 0, 'yes', 'no') AS col1 FROM mytable) t2

Answer 3

Enclose the subquery in parentheses:

SELECT IF ((SELECT COUNT(*) FROM mytable), 'yes', 'no');