diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml index c49d81b7f90935827ac9121dff21fb8979884200..8761b6e1da71c987b93d618426ed7cba37a4696a 100644 --- a/doc/src/sgml/syntax.sgml +++ b/doc/src/sgml/syntax.sgml @@ -1,4 +1,4 @@ - + SQL Syntax @@ -1740,15 +1740,15 @@ SELECT somefunc() OR true; used. For example, this is an untrustworthy way of trying to avoid division by zero in a WHERE clause: -SELECT ... WHERE x <> 0 AND y/x > 1.5; +SELECT ... WHERE x > 0 AND y/x > 1.5; But this is safe: -SELECT ... WHERE CASE WHEN x <> 0 THEN y/x > 1.5 ELSE false END; +SELECT ... WHERE CASE WHEN x > 0 THEN y/x > 1.5 ELSE false END; A CASE construct used in this fashion will defeat optimization attempts, so it should only be done when necessary. (In this particular - example, it would be best to sidestep the problem by writing + example, it would be better to sidestep the problem by writing y > 1.5*x instead.)