Difference between revisions of "DESCRIPTION Column Constraint"
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==Example== | ==Example== | ||
<code lang="recital"> | <code lang="recital"> | ||
| − | + | ALTER TABLE customer; | |
| − | + | ADD COLUMN dateref DATE; | |
| − | ALTER TABLE customer ADD COLUMN dateref | + | DEFAULT date(); |
| − | DEFAULT date() DESCRIPTION "Date Reference" | + | DESCRIPTION "Date Reference" |
| − | + | ||
| − | + | ||
</code> | </code> | ||
Revision as of 11:22, 22 December 2009
Purpose
Column constraint to set the column description for the specified column
Syntax
DESCRIPTION <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 DESCRIPTION column constraint is used to set the column description for the specified column. The <expC> is a character expression of up to 25 characters.
Example
ALTER TABLE customer; ADD COLUMN dateref DATE; DEFAULT date(); DESCRIPTION "Date Reference"
Products
Recital, Recital Server
