importedkeys

Return information about imported foreign keys

Syntax

i = importedkeys(dbmeta, 'cata', 'sch')
i = importedkeys(dbmeta, 'cata', 'sch', 'tab')

Description

i = importedkeys(dbmeta, 'cata', 'sch') returns foreign imported key information, that is, information about fields that reference primary keys in other tables, in the schema sch, of the catalog cata, for the database whose database metadata object is dbmeta.

i = importedkeys(dbmeta, 'cata', 'sch', 'tab') returns foreign imported key information in the table tab. In turn, fields in tab reference primary keys in other tables in the schema sch, of the catalog cata, for the database whose database metadata object is dbmeta.

Examples

Get foreign key information for the schema SCOTT in the catalog orcl, for dbmeta.

i = importedkeys(dbmeta,'orcl','SCOTT')
i = 
  Columns 1 through 7
    'orcl'   'SCOTT'   'DEPT'   'DEPTNO'    'orcl'...
    'SCOTT'    'EMP'
  Columns 8 through 13
    'DEPTNO'    '1'    'null'    '1'    'FK_DEPTNO'...
    'PK_DEPT'

The results show foreign imported key information as described in the following table.

ColumnDescriptionValue

1

Catalog containing primary key, referenced by foreign imported key

orcl

2

Schema containing primary key, referenced by foreign imported key

SCOTT

3

Table containing primary key, referenced by foreign imported key

DEPT

4

Column name of primary key, referenced by foreign imported key

DEPTNO

5

Catalog that has foreign imported key

orcl

6

Schema that has foreign imported key

SCOTT

7

Table that has foreign imported key

EMP

8

Foreign key column name, that is the column name that references the primary key in another table

DEPTNO

9

Sequence number within foreign key

1

10

Update rule, that is, what happens to the foreign key when the primary key updates

null

11

Delete rule, that is, what happens to the foreign key when the primary key is deleted

1

12

Foreign imported key name

FK_DEPTNO

13

Primary key name in referenced table

PK_DEPT

In the schema SCOTT, there is only one foreign imported key. The table EMP contains a field, DEPTNO, that references the primary key in the DEPT table, the DEPTNO field.

EMP is the referencing table and DEPT is the referenced table.

DEPTNO is a foreign imported key in the EMP table. Reciprocally, the DEPTNO field in the table DEPT is an exported foreign key and the primary key.

For a description of the codes for update and delete rules, see the getImportedKeys property on the Oracle® Java® Web site:

http://docs.oracle.com/javase/7/docs/api/java/sql/DatabaseMetaData.html.

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