Difference between revisions of "PREDICATES"
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Yvonne.milne (Talk | contribs) (Created page with '==Purpose== Special operators ==See Also== INSERT, SELECT, UPDATE ==Description== Predicates are special operators. They are used …') |
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Predicates are special operators. They are used to evaluate an expression and return True (.T.), False (.F.) or Unknown (.NULL.). | Predicates are special operators. They are used to evaluate an expression and return True (.T.), False (.F.) or Unknown (.NULL.). | ||
| − | {| class="wikitable" | + | {| class="wikitable" width=100% |
| − | !Predicate||Description | + | !width=30%|Predicate||Description |
|- | |- | ||
| − | |[[BETWEEN Predicate|BETWEEN]]||Evaluate whether an expression is between two other expressions. | + | |valign=top|[[BETWEEN Predicate|BETWEEN]]||Evaluate whether an expression is between two other expressions. |
|- | |- | ||
| − | |[[IN Predicate|IN]]||Evaluate whether an expression matches one of a set of values. | + | |valign=top|[[IN Predicate|IN]]||Evaluate whether an expression matches one of a set of values. |
|- | |- | ||
| − | |[[LIKE Predicate|LIKE]]||Evaluate whether an expression is like another expression | + | |valign=top|[[LIKE Predicate|LIKE]]||Evaluate whether an expression is like another expression |
|- | |- | ||
| − | |[[NULL Predicate|NULL]]||Evaluate whether an expression is equal to .NULL. | + | |valign=top|[[NULL Predicate|NULL]]||Evaluate whether an expression is equal to .NULL. |
|- | |- | ||
|} | |} | ||
Revision as of 12:42, 22 January 2013
Purpose
Special operators
See Also
Description
Predicates are special operators. They are used to evaluate an expression and return True (.T.), False (.F.) or Unknown (.NULL.).
| Predicate | Description |
|---|---|
| BETWEEN | Evaluate whether an expression is between two other expressions. |
| IN | Evaluate whether an expression matches one of a set of values. |
| LIKE | Evaluate whether an expression is like another expression |
| NULL | Evaluate whether an expression is equal to .NULL. |
