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nothing | commit () |
| | flushes any queued data and commits the transaction
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| | constructor (string name, SqlUtil::AbstractTable target, *hash opts) |
| | creates the object from the supplied arguments More...
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| | constructor (string name, SqlUtil::Table target, *hash opts) |
| | creates the object from the supplied arguments More...
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| | destructor () |
| | throws an exception if there is data pending in the internal row data cache; make sure to call flush() or discard() before destroying the object More...
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| | discard () |
| | discards any buffered batched data; this method should be called before destroying the object if an error occurs More...
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| | flush () |
| | flushes any remaining batched data to the database; this method should always be called before committing the transaction or destroying the object More...
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Qore::SQL::AbstractDatasource | getDatasource () |
| | returns the AbstractDatasource object associated with this object
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int | getRowCount () |
| | returns the affected row count
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SqlUtil::AbstractTable | getTable () |
| | returns the underlying SqlUtil::AbstractTable object
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string | getTableName () |
| | returns the table name
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| | queueData (hash data) |
| | queues row data in the block buffer; the block buffer is flushed to the DB if the buffer size reaches the limit defined by the block_size option; does not commit the transaction More...
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| | queueData (list l) |
| | queues row data in the block buffer; the block buffer is flushed to the DB if the buffer size reaches the limit defined by the block_size option; does not commit the transaction More...
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nothing | rollback () |
| | discards any queued data and rolls back the transaction
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| int | size () |
| | returns the current size of the cache as a number of rows More...
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base class for bulk DML operations
This is an abstract base class for bulk DML operations; this class provides the majority of the API support for bulk DML operations for the concrete child classes that inherit it.
- Submitting Data
- To use this class's API, queue data in the form of a hash (a single row or a set of rows) or a list of rows by calling the queueData() method.
The queueData() method queues data to be written to the database; the queue is flush()ed automatically when block_size rows have been queued.
- Flushing and Discarding Data
- Each call to flush() (whether implicit or explicit) will cause a single call to be made to the dataserver; all queued rows are sent in a single bulk DML call, which allows for efficient processing of large amounts of data.
A call to flush() must be made before committing the transaction to ensure that any remaining rows in the internal queue have been written to the database. Because the destructor() will throw an exception if any data is left in the internal queue when the object is destroyed, a call to discard() must be made prior to the destruction of the object in case of errors.
on_success ds.commit();
on_error ds.rollback();
{
on_success {
op1.flush();
op2.flush();
}
on_error {
op1.discard();
op2.discard();
}
map op1.queueData($1), data1.iterator();
map op2.queueData($1), data2.iterator();
}
- Note
- Each bulk DML object must be manually flush()ed before committing or manually discard()ed before rolling back to ensure that all data is managed properly in the same transaction and to ensure that no exception is thrown in the destructor(). See the example above for more information.
- If the underlying driver does not support bulk operations, then such support is emulated with single SQL operations; in such cases performance will be reduced. Call SqlUtil::AbstractTable::hasArrayBind() to check at runtime if the driver supports bulk SQL operations.
