The value of the Direction field also determines whether values are read or written to the relational database as follows:
Out – Send the values of the specified block and field name pairs to the relational database. These values update existing values, are inserted in the relational database, or used in a Where clause. Typically, the number of Out fields equals the number of parameters in INSERT or UPDATE commands.
In – Receive the values of the specified block and field name pairs from the relational database. Typically, the number of In fields equals the number of columns specified in the SELECT commands.
For example, using the command shown below, you can add a new record in the relational database:
INSERT into TBL1 (COL1, COL2, COL3) values (?, ?, ?)
The direction for each value in this example is set to OUT.