The form to set constraints, and choose which parameters to display, needs some expertise... It is powerful, but we recommend to read the following introduction before getting discouraged by the lack of success.
The constraints have to be written directly in SQL, the language of the database server. Some of the most common constraints you may like to use are:
SQL statement | Example | Explanation |
---|---|---|
= | = 'HR' | equality, note the single quote around the character string. |
= | = 15 | equality, numrical values are not quoted. |
!= | != 'not public' | not equal |
IS NULL | IS NULL | does not have a value |
IS NOT NULL | IS NOT NULL | has a value |
IN | IN ('F8', 'G0') | is in a list of values |
< | < 200 | less than, also ≤ |
> | > 300 | greater than, also ≥ |
BETWEEN | BETWEEN -10 AND 10 | in a range of values |
LIKE | LIKE 'G2%' | pattern matching, % is a wildcard |