Use the
ALTER TABLE..MODIFY clause to change one or more attributes of a table's IDENTITY column and its Sequence Generator (SG) options.
Each IDENTITY column is generated in one of the following ways:
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Oracle Auto Increment Primary Key 12c![]()
This section presents ways to change or drop an IDENTITY column from a table. The
ALTER TABLE statement lets you add, remove, or alter a field in any table definition. Use the ALTER TABLE statement to modify an IDENTITY field.
Note:
The MODIFY clause in an ALTER TABLE.. statement is supported only on IDENTITY columns.
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The next example adds an IDENTITY field to a new table,
test_alter , created without an IDENTITY. The example also specifies several attributes for the associated SG for test_alter :
To remove the IDENTITY column, so no such field remains, use
ALTER TABLE with a DROP id clause: Counter strike 1.6 steam cd key generator free download.
To keep the
id column, but remove its IDENTITY definition, use ALTER TABLE with a MODIFY id DROP IDENTITY clause:
Auto Generated Primary Key In Oracle
Putty key generator download for linux windows 7. You can change the SG attributes. The new values take effect on subsequent client calls to access the SG attributes. For example, this happens when the cache has no more values, or when the attributes stored at the client have timed out.
To change the basic property of an IDENTITY column being
GENERATED ALWAYS to GENERATED BY DEFAULT , see the next ALTER TABLE example. The example also shows how to change the SG attributes from their original definitions, START WITH , INCREMENT BY , MAXVALUE , CACHE and CYCLE .
Note:
The client has a time-based cache to store the SG Attributes. The client connects to the server to refresh this cache after it expires. The default timeout is 5 minutes. Change this default by setting sgAttrsCacheTimeout in KVStoreConfig.
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