CODEWITHSUNDEEP
mysqlsyntaxif-statementexists
Mohammad Saberi
Mohammad Saberi

Reputation: 13166

Does MySQL support "IF EXISTS"?

I think I have a conflict between my knowledge on SQL Server and MySQL.
When I run this query, I get an error always from MySQL:

If EXISTS (select * from tbl_admin) THEN
    select 'OK';
END IF;

The error message is:

[Err] 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 tbl_admin) then select '1' -- select '1' WHERE EXISTS ' at line 1

Please help me and tell me am I wrong in writing this query? What's wrong?
I want to do something if I have something in tbl_admin table.

Upvotes: 1

Views: 12512

Answers (7)

juergen d
juergen d

Reputation: 204766

select 'ok'
from INFORMATION_SCHEMA.tables
where table_name = 'tbl_admin'

edit

To check if a table contains data you can do this:

SELECT 'OK' FROM dual
WHERE EXISTS (SELECT * FROM tbl_admin);

Upvotes: 3

satdev86
satdev86

Reputation: 810

select if(count(*), 'OK', '') as result from table_name where 1

This will print "OK" if there are records present, else nothing will be shown.

Upvotes: 0

Ajay Kadyan
Ajay Kadyan

Reputation: 1079

if you want to check table existence then use this

 select 'Message' from INFORMATION_SCHEMA.tables where table_name = 'tbl_admin'

because all information is stored here.EXISTS also works fine in mysql.

Upvotes: 0

manurajhada
manurajhada

Reputation: 5380

select case when count(*) > 0 then 'OK' else 'Empty' end from tbl_admin;

OR 

select 'OK' from tbl_admin having count(*) > 0;

Upvotes: 0

Raul Rene
Raul Rene

Reputation: 10270

You can do something like:

if ( (select count(*) from tbl_admin) > 0) then
    ...

This counts all the rows in the table. If no rows are there, it will return 0.

Upvotes: 1

Zagor23
Zagor23

Reputation: 1963

If I understand correctly, you know there is a table, you just need an info if there are any rows? In that case I think this solves your problem:

SELECT 
    'OK'
FROM
    Korisnik
WHERE
    EXISTS( SELECT 
            COUNT(*)
        FROM
            Korisnik)
LIMIT 1;

You can use IF EXISTS to check for stored procedure or trigger existence. In SELECT queries you can use WHERE EXISTS or WHERE NOT EXISTS

http://dev.mysql.com/doc/refman/5.5/en/exists-and-not-exists-subqueries.html

Upvotes: 1

Sashi Kant
Sashi Kant

Reputation: 13465

Use the normal select query..

Select 'OK' from table

Upvotes: -2

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