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Using database event transformers

Database event transformers are a graphical alternative to CQs for modifying the output of SQL CDC sources (see CREATE CQ (query) and Working with SQL CDC readers).

You can use DB event transformers with sources.

If you convert a transformer to a CQ, you cannot convert it back to a transformer.

Expressions may use the same Operators and Functions as CQ SELECT statements. Enclose literal string values in quotes.

Custom Data Adder
CustomDataAdder.png

Adds one or more fields to the USERDATA map (see Adding user-defined data to WAEvent streams). For each field, enter a name, select a data type, and enter an expression.

Data Modifier
DataModifier.png

Modifies one field in the DATA array. Select the table, select the column, and enter an expression.

This transformer can be used only with MSSQLReader, MySQLReader, or OracleReader, and Striim must be able to connect to the database to download table descriptions.

Metadata Filter
MetadataFilter.png

Filters the input events based on one or more metadata field values.

Operation Filter
OperationFilter.png

Passes only events with the selected operation type to the output stream. Select DELETE, INSERT, or UPDATE.

Table Filter
TableFilter.png

Passes only the selected table to the output stream.

This transformer can be used only with MSSQLReader, MySQLReader, or OracleReader, and Striim must be able to connect to the database to download table descriptions.

To Event
ToEvent.png

Creates a Striim Type for the output stream based on the column names and data types of the selected table and converts WAEvent input to typed output (see Parsing the data field of WAEvent). Only events from the selected table are included in the output stream.

This transformer can be used only with MSSQLReader, MySQLReader, or OracleReader, and Striim must be able to connect to the database to download table descriptions.

To Staging
ToStaging.png

Copies the values of the OperationName field in the METADATA map to the OrigOperationName field in the USERDATA map (see Adding user-defined data to WAEvent streams). Typically you would use this in an application that writes to a data warehouse or other target where UPDATE and DELETE operations are handled as INSERTs (see How update and delete operations are handled in writers).