-ForeignMultiKeyNullifier (Oracle - Berkeley DB Java API) -

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```
public interface ForeignMultiKeyNullifier
```
+
The interface implemented for setting multi-valued foreign keys to null.
A key nullifier is used with a secondary database that is configured to - have a foreign key integrity constraint and a delete action of ForeignKeyDeleteAction.NULLIFY. The key nullifier is specified by calling - SecondaryConfig.setForeignMultiKeyNullifier(com.sleepycat.db.ForeignMultiKeyNullifier).
+ have a foreign key integrity constraint and a delete action of ForeignKeyDeleteAction.NULLIFY. The key nullifier is specified by calling + SecondaryConfig.setForeignMultiKeyNullifier(com.sleepycat.db.ForeignMultiKeyNullifier).

When a referenced record in the foreign key database is deleted and the - foreign key delete action is NULLIFY, the nullifyForeignKey(com.sleepycat.db.SecondaryDatabase, com.sleepycat.db.DatabaseEntry, com.sleepycat.db.DatabaseEntry, com.sleepycat.db.DatabaseEntry) method is called. This method + foreign key delete action is NULLIFY, the nullifyForeignKey(com.sleepycat.db.SecondaryDatabase, com.sleepycat.db.DatabaseEntry, com.sleepycat.db.DatabaseEntry, com.sleepycat.db.DatabaseEntry) method is called. This method sets the foreign key reference to null in the datum of the primary database. The primary database is then updated to contain the modified datum. The result is that the secondary key is deleted.
- This interface may be used along with SecondaryKeyCreator or SecondaryMultiKeyCreator for many-to-many, one-to-many, many-to-one and - one-to-one relationships. -
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- + This interface may be used along with SecondaryKeyCreator or SecondaryMultiKeyCreator for many-to-many, one-to-many, many-to-one and + one-to-one relationships.
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-Method Summary
- `boolean`	`nullifyForeignKey(SecondaryDatabase secondary, - DatabaseEntry key, - DatabaseEntry data, - DatabaseEntry secKey)` - - - Sets the foreign key reference to null in the datum of the primary - database.

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Method Summary

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Methods
Modifier and Type	Method and Description
`boolean`	`nullifyForeignKey(SecondaryDatabase secondary, + DatabaseEntry key, + DatabaseEntry data, + DatabaseEntry secKey)` + Sets the foreign key reference to null in the datum of the primary + database. +

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-Method Detail
- -
-nullifyForeignKey
-
```
-boolean nullifyForeignKey(SecondaryDatabase secondary,
-                          DatabaseEntry key,
-                          DatabaseEntry data,
-                          DatabaseEntry secKey)
-                          throws DatabaseException
```
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-
Sets the foreign key reference to null in the datum of the primary - database. -
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Parameters:
secondary - the database in which the foreign key integrity +
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Method Detail
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+
nullifyForeignKey
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boolean nullifyForeignKey(SecondaryDatabase secondary, + DatabaseEntry key, + DatabaseEntry data, + DatabaseEntry secKey) + throws DatabaseException
+
Sets the foreign key reference to null in the datum of the primary + database.
+
Parameters:
secondary - the database in which the foreign key integrity constraint is defined. This parameter is passed for informational - purposes but is not commonly used.
key - the existing primary key. This parameter is passed for - informational purposes but is not commonly used.
data - the existing primary datum in which the foreign key + purposes but is not commonly used.
key - the existing primary key. This parameter is passed for + informational purposes but is not commonly used.
data - the existing primary datum in which the foreign key reference should be set to null. This parameter should be updated by - this method if it returns true.
secKey - the secondary key to be nullified. This parameter is + this method if it returns true.
secKey - the secondary key to be nullified. This parameter is needed for knowing which key to nullify when multiple keys are present, - as when SecondaryMultiKeyCreator is used. -
Returns:
true if the datum was modified, or false to indicate that the - key is not present. -
Throws: -
DatabaseException - if an error occurs attempting to clear the key - reference.
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+ as when SecondaryMultiKeyCreator is used.
+
Returns:
true if the datum was modified, or false to indicate that the + key is not present.
+
Throws:
+
DatabaseException - if an error occurs attempting to clear the key + reference.
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- -com.sleepycat.db -
-Interface ForeignMultiKeyNullifier

Interface ForeignMultiKeyNullifier

Method Summary

-nullifyForeignKey

Method Detail

nullifyForeignKey

- -com.sleepycat.db - -Interface ForeignMultiKeyNullifier

Interface ForeignMultiKeyNullifier

Method Summary

-nullifyForeignKey

Method Detail

nullifyForeignKey

- -com.sleepycat.db -
-Interface ForeignMultiKeyNullifier