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SYSTEM.CONSTRAINT contains detailed information about the integrity
constraints contained in the database. Initially, the table is empty. ALLBASE/SQL updates
this table when processing a
CREATE TABLE, ALTER TABLE, CREATE VIEW, DROP TABLE, DROP VIEW, or
TRANSFER OWNERSHIP statement involving an integrity constraint. This table is accessed whenever an INSERT, format II INSERT, UDPATE, or
DELETE is performed on a table to determine if any integrity constraints
need to be enforced. Further checking into SYSTEM.CONSTRAINTCOL is made
if a table is found in SYSTEM.CONSTRAINT, to enforce referential
constraints (UNIQUE, PRIMARY KEY, FOREIGN KEY) on a column-dependent
basis. Table 8-8 System.Constraint | Column Name | Type | Length | Description |
|---|
| CONSTRAINTNAME | CHAR | 20 | Name of the constraint | | OWNER | CHAR | 20 | Owner of the table or view | | TABLENAME | CHAR | 20 | Name of the table or view | | TYPE | CHAR | 2 | Type of constraint:
- C
table check constraint
- P
primary key
- R
referential constraint
(foreign key)
- U
unique constraint
(key other than primary)
- V
view check constraint
| | INDEXTYPE | CHAR | 2 | Type of index used:
- C
clustered index
- H
hash structure
- N
none specified
| | NUMC | INTEGER | 4 | Number of columns in the constraint
if TYPE is one of P, R, or U. | | REFOWNER | CHAR | 20 | Owner of the key column referenced
in a FOREIGN KEY constraint | | REFCONSTRAINT | CHAR | 20 | Constraint Name of the key column
referenced in a FOREIGN
KEY constraint
| | DBEFILESET | CHAR | 20 | Name of the DBEFileSet containing the
stored section for a table check constraint (blank if not applicable)
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Example | |
SELECT * FROM System.Constraint;
--------------------+--------------------+--------------------+----+---------
CONSTRAINTNAME |OWNER |TABLENAME |TYPE|INDEXTYPE
--------------------+--------------------+--------------------+----+---------
SQLCON_00000001P00 |PURCHDB |PARTS1 |P |N
CLUBS_PK |RECDB |CLUBS |P |N
MEMBERS_PK |RECDB |MEMBERS |P |N
MEMBERS_FK |RECDB |MEMBERS |R |N
EVENTS_FK |RECDB |EVENTS |R |N
---------------------------------------------------------------------------
Number of rows selected is 5
U[p], d[own], l[eft], r[ight], t[op], b[ottom], pr[int] <n>, or e[nd]> r
+-----------+--------------------+--------------------+--------------------
|NUMC |REFOWNER |REFCONSTRAINT |DBEFILESET
+-----------+--------------------+--------------------+--------------------
| 1| | |
| 1| | |
| 2| | |
| 1|RECDB |CLUBS_PK |
| 2|RECDB |MEMBERS_PK |
---------------------------------------------------------------------------
Number of rows selected is 5
U[p], d[own], l[eft], r[ight], t[op], b[ottom], pr[int] <n>, or e[nd]> r
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