Question

In C# if I run the following.

if(obj.a() && obj.b()){
    // do something
}

Function b will only execute if a returns true. Does the same thing happen below?

select
    *
from
    tablea a
    inner join tableb b
        isnumeric(b.col1) = 1
        and cast(b.col1 as int) = a.id

Will the cast only be executed when b.col1 is a numeric?

Answer 1

You can simulate short-circuit evaluation using a CASE expression.

ON CASE WHEN ISNUMERIC(b.col1) = 1
       THEN CAST(b.col1 AS int)
       ELSE NULL
   END = a.id