Difference between revisions of "SQL Constraints"
From Lianjapedia
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|[[ONAFTERINSERT Table Constraint|ONAFTERINSERT]]||[[ONAFTERUPDATE Table Constraint|ONAFTERUPDATE]]||[[ONCLOSE Table Constraint|ONCLOSE]] | |[[ONAFTERINSERT Table Constraint|ONAFTERINSERT]]||[[ONAFTERUPDATE Table Constraint|ONAFTERUPDATE]]||[[ONCLOSE Table Constraint|ONCLOSE]] | ||
|- | |- | ||
− | |[[ | + | |[[ONBEFOREDELETE Table Constraint|ONBEFOREDELETE]] / [[ONDELETE Table Constraint|ONDELETE]]||[[ONBEFOREINSERT Table Constraint|ONBEFOREINSERT]] / [[ONINSERT Table Constraint|ONINSERT]]||[[ONOPEN Table Constraint|ONOPEN]] |
|- | |- | ||
− | |[[ONROLLBACK Table Constraint|ONROLLBACK]]||[[ONUPDATE Table Constraint|ONUPDATE]]||[[PRIMARY KEY Table Constraint|PRIMARY KEY]] | + | |[[ONROLLBACK Table Constraint|ONROLLBACK]]||[[ONBEFOREUPDATE Table Constraint|ONBEFOREUPDATE]] / [[ONUPDATE Table Constraint|ONUPDATE]]||[[PRIMARY KEY Table Constraint|PRIMARY KEY]] |
|- | |- | ||
|[[UNIQUE Table Constraint|UNIQUE]]|||| | |[[UNIQUE Table Constraint|UNIQUE]]|||| |
Revision as of 07:30, 21 November 2012
Purpose
To define rules that help to provide data integrity
See Also
ALTER TABLE, CREATE TABLE, GRANT, REVOKE
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 |
ONROLLBACK | ONBEFOREUPDATE / ONUPDATE | PRIMARY KEY |
UNIQUE |
Column Constraints
AUTO_INCREMENT | AUTOINC | CALCULATED |
CHECK | DEFAULT | DESCRIPTION |
ERROR | FOREIGN KEY | NOCPTRANS |
NOT NULL | NULL | PRIMARY KEY |
RANGE | RECALCULATE | REFERENCES |
SET CHECK | UNIQUE |