Each horizontal item below represents a call to DBCHCL, with function code set as in the left column.
| Function | Description |
|---|---|
| Connect |
Application must have set address and length of logon string. All other arguments (buffer sizes, run string, and various other arguments) are optional and will default if they are left unset. |
| Fetch | Fetch response data, always one of the following parcels:
|
| Initiate Request |
Send Teradata SQL request to the database. Application must set address and length of the Teradata SQL request and optional using data. |
| Fetch |
Fetch response data. DBCHCL returns address and length of first parcel (or buffer, if in buffer mode). The DBCHCL does the following, depending on whether dual buffering is specified and the status of the current buffer:
|
| End Request | Clean up request-related context. |
| Disconnect | Log off from the database and free the session-related control blocks |