Difference between revisions of "CHOICES Column Constraint"
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A constraint is used to define rules that help to provide data integrity. Column constraints are specific to the column name specified. You must have ALTER privilege on the table. The table will be locked for EXCLUSIVE use during the operation. | A constraint is used to define rules that help to provide data integrity. Column constraints are specific to the column name specified. You must have ALTER privilege on the table. The table will be locked for EXCLUSIVE use during the operation. | ||
| − | The CHOICES column constraint is used to specify a choice list for a character column. The <expC> can be a static choice list based on comma-separated options or a dynamic choice list using "@tablename,expression" or a | + | The CHOICES column constraint is used to specify a choice list for a character column. The <expC> can be a static choice list based on comma-separated options or a dynamic choice list using "@tablename,expression" or a [[SQL SELECT]] statement. |
==Example== | ==Example== | ||
Latest revision as of 11:17, 11 February 2013
Contents
Purpose
Column constraint to specify a choice list for a character column
Syntax
SET CHOICES <expC>
See Also
ALTER TABLE, CONSTRAINTS, CREATE TABLE
Description
A constraint is used to define rules that help to provide data integrity. Column constraints are specific to the column name specified. You must have ALTER privilege on the table. The table will be locked for EXCLUSIVE use during the operation.
The CHOICES column constraint is used to specify a choice list for a character column. The <expC> can be a static choice list based on comma-separated options or a dynamic choice list using "@tablename,expression" or a SQL SELECT statement.
Example
open database southwind // Static choices ALTER TABLE "example" MODIFY CONSTRAINT TITLE SET CHOICES "Mr,Mrs,Ms" // Dynamic choices @tablename,expression ALTER TABLE "orders" MODIFY CONSTRAINT CUSTOMERID SET CHOICES "@customers,customerid" // Dynamic choices SQL Select ALTER TABLE "orders" MODIFY CONSTRAINT CUSTOMERID SET CHOICES "select customerid from customers"
