Comparing two rows in mysql with additional check

Question

Heysa,

I have this little problem that im not quite good at mysql queries and i don't know proper terminology for this question so i'll just roll as i can :)

I have 2 rows in 1 table that i want to compare if they are not 0 and are equal. In php it would look something like this:

if(!empty($row1) && !empty($row2)){
   if($row1==$row2){
       return true;
   }else{
      return false;
   }
}else{
   return false;
}

Here is table if that's any help

id | b | t |
-----------
1 | 2 | 1 |
2 | 0 | 0 | 
3 | 1 | 1 |

And this:

SELECT * FROM table WHERE b=t

Returns also 0=0 record with id=2 ( that i don't want )

Correct query should return only record with id=3

What is your table structure? What columns are you using to link the rows? What has to be not 0? — Martin Smith
– Martin Smith, Commented Dec 2, 2010 at 1:09

Simen Echholt · Accepted Answer · 2010-12-02 01:21:32Z

3

SELECT * FROM table WHERE b = t AND b <> 0 AND t <> 0

Since we're testing that b = t, we know that if b <> 0 is true, then t <> 0 is also true. We can therefore shorten it to

SELECT * FROM table WHERE b = t AND b <> 0

answered Dec 2, 2010 at 1:21

Simen Echholt

11.3k2 gold badges36 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Comparing two rows in mysql with additional check

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related