Many-to-many mapping is useful for specific database operations used in DataInsert and DataUpdate nodes, because it acts on a group of related mappings bound together through a single row unification. This mapping requires user-specified operations to clarify what the relationships are between each target and its sources, and there can be an equal or unequal number of each.
Many-to-many mappings are available only for database targeted mappings.
Many-to-many mapping is a way to define a message-to-database mapping that uses the WHERE clause, for example:
UPDATE Tbl SET col1 = Op1(a, b, c); SET col2 = Op2(a, b, c); SET col3 = Op3(a, b, c): WHERE Condition(a, b, c);
Source | Target |
Msg
|
Tbl
|
In this example Op1, Op2, and Op3 are arbitrary operations performed on fields a, b, and c.
You could define this mapping using multiple many-to-one mappings and copying the WHERE clause.
When a many-to-one or a many-to-many mapping is performed, you must define how the multiple elements are dealt with when they are placed into the single target element. For example, the source elements might need to be concatenated or have a mathematical function applied to them.
Related concepts
One-to-one mapping
One-sided mapping
One-to-many mapping
Many-to-one mapping
DataUpdate mapping
DataInsert mapping
Related tasks
Developing mappings
Adding a many-to-many mapping
Related reference
Mappings
Notices |
Trademarks |
Downloads |
Library |
Support |
Feedback
![]() ![]() |
ar00950_ |