]
07-20-2023, 02:19 PM
`1=1` will always be true, so the `value="TOYOTA"` bit is the important one.
You get this in a few scenarios including:
Generated SQL: It's easier to create a generate a complex `where` statement if you don't have to work out if you're adding the first condition or not, so often a `1=1` is put at the beginning, and all other conditions can be appended with an `And`
Debugging: Sometimes you see people put in a `1=1` at the top of a where condition as it enables them to freely chop and change the rest of the conditions when debugging a query. e.g.
select * from car_table
where 1=1
--and value="TOYOTA"
AND color="BLUE"
--AND wheels=4
It has to be said that it isn't particularly good practice and normally shouldn't occur in production code. It may even not help the optimization of the query very much.
You get this in a few scenarios including:
Generated SQL: It's easier to create a generate a complex `where` statement if you don't have to work out if you're adding the first condition or not, so often a `1=1` is put at the beginning, and all other conditions can be appended with an `And`
Debugging: Sometimes you see people put in a `1=1` at the top of a where condition as it enables them to freely chop and change the rest of the conditions when debugging a query. e.g.
select * from car_table
where 1=1
--and value="TOYOTA"
AND color="BLUE"
--AND wheels=4
It has to be said that it isn't particularly good practice and normally shouldn't occur in production code. It may even not help the optimization of the query very much.