Subject: [Pljava-dev] PLJAVA Trigger Function more arguments
Date: Wed, 2 Nov 2005 08:39:59 -0600
Message-ID: <95C1D62B-0CF7-40B9-A378-080E088DEE4A@rakeshv.org> (raw)
In-Reply-To: <5234B8D9C36F9E4D9B1AF01013708B6B0152C05B@txindoki.tekniker.es>
References: <5234B8D9C36F9E4D9B1AF01013708B6B0152C05B@txindoki.tekniker.es>
On 2 Nov 2005, at 08:30, Ignacio L?zaro wrote:
>> Do you mean execute a SQL statement from within a Trigger? That
>> should be possible using the usual JDBC techniques. The trigger body
>> can execute any standard Java code, provided that the TriggerData can
>> supply you with the information you need to execute the associated
>> code.
>>
>
> I am not very sure, you mean that the trigger body is inside
> postgreSQL or inside the java class??
> do you have any example ?
> Regards
> Nacho
The following is the only time I have done a trigger in PL/Java:
/**
* The trigger to be invoked when deleting a <code>Group</code>
* record. All <code>User</code> records that are exclusively
* associated with the <code>Group</code> specified will be
* deleted.
*
* @see UserFunctions#deleteByGroup
* @param triggerData The PostgreSQL provided interface with
* data pertaining to the old or new records as appropriate
* @throws SQLException If errors are encountered while deleting
* the User records. Also thrown if the trigger is fired by
* a <code>non-delete</code> operation on the table.
*/
public static void deleteTrigger( TriggerData triggerData )
throws SQLException
{
if( triggerData.isFiredByDelete() &&
triggerData.isFiredForEachRow() )
{
ResultSet resultSet = null;
try
{
resultSet = triggerData.getOld();
resultSet.next();
UserFunctions.deleteByGroup( resultSet.getInt( "groupId" ) );
}
finally
{
CloseResources.close( resultSet );
}
}
else
{
throw new TriggerException( triggerData,
"Can process only DELETE events on each row" );
}
}
The UserFunctions.deleteByGroup is defined as:
/**
* Delete all the <code>Users</code> who are solely associated with
* the specified <code>Group</code>.
*
* @param groupId The primary key value of the group whose exclusive
* users are to be deleted.
* @return boolean - Returns <code>false</code> to indicate that the
* executing the statement returns nothing.
* @throws SQLException If errors are encountered while deleting
* the users.
*/
public static final boolean deleteByGroup( int groupId )
throws SQLException
{
Connection connection = null;
PreparedStatement statement = null;
try
{
connection = ConnectionFactory.getConnection();
statement = connection.prepareStatement( deleteByGroup );
statement.setInt( 1, groupId );
statement.setInt( 2, groupId );
statement.execute();
}
finally
{
CloseResources.close( statement );
CloseResources.close( connection );
}
return false;
}
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To: pljava-dev@postgresql.org
Subject: Re: [Pljava-dev] PLJAVA Trigger Function more arguments
In-Reply-To: <95C1D62B-0CF7-40B9-A378-080E088DEE4A@rakeshv.org>
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