Procedures tell Host Integrator how to fulfill the queries it receives from client applications. The procedures you create for your table determine what host data can be read, inserted, updated, or deleted. Each procedure has a unique signature that describes what it does. The signature includes a procedure type (SELECT, UPDATE, INSERT, and DELETE) and a set of parameters. Host Integrator uses these signatures to translate SQL statements into a set of procedures.
Procedures use one or two of the three types of parameters:
The key component of a procedure's definition is the parameter mapping. Each
parameter in a procedure corresponds to a column in the table and is mapped
to an attribute, a recordset field, or another parameter. Each procedure has
a predefined traversal path through the host application; during the traversal
operations, data is exchanged between parameters and attributes and recordset
fields. The following chart shows which parameters are used in which procedures:
| Filter Parameters | Data Parameters | Output Parameters | |
| SELECT |
X
|
X
|
|
| UPDATE |
X
|
X
|
|
| INSERT |
X
|
||
| DELETE |
X
|
Procedures should be as complete as possible: if you do not provide a procedure
for a particular operation, it is not be possible for a client application to
access or modify that table data. Procedures should also contain robust error
handling to recover from unexpected or incomplete queries. Using the Procedure
Editor, you can include error entities
that define errors returned from a procedure.
Use the Procedure Wizard to quickly create a basic procedure. For more complicated procedures, create the procedure using the Tables dialog box and the Procedure Editor.
After adding procedures to your model, you can use Web Builder to quickly and easily generate a web application or a component interface, such as a web service or JavaBeans, based on the procedures of a host application model.
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