Question

I have table with the following data in table clients

------------------
|id|client|status|
------------------
|1 |331   |  0   |
|2 |331   |  1   |
|3 |331   |  2   |
|4 |331   |  1   |
|5 |331   |  0   |
|6 |222   |  0   |
------------------

I like to retrieve all the fields from the table clients where client is 331 and having status 0 or 1. That means I will be getting id 1,2,4,5 as the result.

But when i used this sql

$query = mysql_query("select * from clients where client=331 AND status=0 or status=1")

I am getting id 1,2,4,5,6 instead.

Whats the correct way to get the data?

Answer 1

Use

select * from clients where client=331 AND (status=0 or status=1)

The order of precedence for logical operators is (Not, And, then Or). As And has higher precedence than Or your query is effectively

select * from clients where (client=331 AND status=0) or status=1

Which is not the desired semantics. You could also use

select * from clients where client=331 AND status in (0,1)