Difference between revisions of "SQL Constraints"
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Yvonne.milne (Talk | contribs) (→Column Constraints) |
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==See Also== | ==See Also== | ||
− | [[ALTER TABLE]], [[CREATE TABLE]], [[GRANT]], [[REVOKE]] | + | [[ALTER TABLE]], [[CREATE TABLE]], [[GRANT]], [[Lianja MetaData API]], [[REVOKE]], [[MetaData Editor|Working with MetaData]] |
==Description== | ==Description== |
Revision as of 04:37, 1 July 2020
Purpose
To define rules that help to provide data integrity
See Also
ALTER TABLE, CREATE TABLE, GRANT, Lianja MetaData API, REVOKE, Working with MetaData
Description
A constraint is used to define rules that help to provide data integrity. There are two different types of constraints, TABLE constraints, which do not require any column information and column constraints, which 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.
Table Constraints
CHECK |
ERROR |
FOREIGN KEY |
INDEX |
KEY |
ONAFTERDELETE |
ONAFTERINSERT |
ONAFTERUPDATE |
ONCLOSE |
ONBEFOREDELETE / ONDELETE |
ONBEFOREINSERT / ONINSERT |
ONOPEN |
ONBEFOREUPDATE / ONUPDATE |
PRIMARY KEY |
UNIQUE |