Revision as of 06:34, 8 November 2010 edit Edward (talk \| contribs) Administrators 94,541 edits m link integrity constraints using Find link ← Previous edit		Revision as of 14:18, 24 June 2012 edit undo Mark Renier (talk \| contribs) Extended confirmed users 3,144 edits →NOT NULL Constraint: // clean up using AWB Next edit →
Line 37: CHECK (''column'' IS NOT NULL) Some [[~~Relational~~relational database management system~~\|relational database management systems~~]]s are able to optimize performance when the <code>NOT NULL</code> constraint syntax is used as opposed to the CHECK constraint syntax given above.<ref>PostgreSQL 8.3devel Documentation, Chapter 5. ''Data Definition'', Section 5.3.2. ''Not-Null Constraints'', Website: http://developer.postgresql.org/pgdocs/postgres/ddl-constraints.html, Accessed on May 5, 2007</ref> == Common Restrictions ==

Check constraint: Difference between revisions