Programming ColdFusion

Transaction Processing

ColdFusion provides support for database transaction processing using the CFTRANSACTION tag. The CFTRANSACTION tag lets you treat all query operations with the <CFTRANSACTION> and </CFTRANSACTION> tags as a single transaction. Changes to the database aren’t committed until all queries in the transaction have executed successfully. In the event a query within the transaction fails, all previous queries are automatically rolled back. The exception to this occurs when the database itself is changed, as in the case when a table or column is created or deleted.

The CFTRANSACTION tag accepts two optional attributes for controlling how transactions are processed, ACTION and ISOLATION:

ACTION

Specifies the transaction action to take. Valid options include:

Begin (default)

Specifies the beginning of the block of code to execute

Commit

Commits a pending transaction

Rollback

Rolls back a pending transaction

ISOLATION

Specifies the ODBC lock type to use for the transaction. The following ODBC lock types are supported: Read_Uncommitted, Read_Committed, Repeat-able_Read, and Serializable.

Note that not all databases and/or database drivers support isolation levels. Many support only a subset of those listed. Refer to your particular database/driver’s documentation for more information on the isolation levels supported.

Example 11-26 shows how to use the CFTRANSACTION tag with two queries that delete records from different tables within the same data source. You need ...