Database Methods

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4D v16.3

4D Language Reference

Database Methods

Database methods are methods that are automatically executed by 4D when a general session event occurs.

To create or open and edit a database method:

Open the Explorer window.
Select the Methods page.
Expand the Database Methods theme.
Double click on the method.

or:

Select the method.
Press Enter or Return.

You edit a database method in the same way as any other method.

You cannot call a database method from another method. Database methods are automatically invoked by 4D at certain points in a working session. The following table summarizes the execution of database methods:

Database Method	4D local	4D Server	4D remote
On Startup	Yes, Once	No	Yes, Once
On Exit	Yes, Once	No	Yes, Once
On Drop	Yes, Multiple	No	Yes, Multiple
On System Event	Yes, Multiple	Yes, Multiple	Yes, Multiple
On Web Connection	Yes, Multiple	Yes, Multiple	Yes, Multiple
On Web Authentication	Yes, Multiple	Yes, Multiple	Yes, Multiple
On Web Session Suspend	Yes, Multiple	Yes, Multiple	Yes, Multiple
On Backup Startup	Yes, Multiple	Yes, Multiple	Yes, Multiple
On Backup Shutdown	Yes, Multiple	Yes, Multiple	Yes, Multiple
On Server Startup	No	Yes, Once	No
On Server Shutdown	No	Yes, Once	No
On Server Open Connection	No	Yes, Multiple	No
On Server Close Connection	No	Yes, Multiple	No
On SQL Authentication	Yes, Multiple	Yes, Multiple	Yes, Multiple
On 4D Mobile Authentication	Yes, Multiple	Yes, Multiple	Non
On Host Database Event	Yes, Multiple	Yes, Multiple	Yes, Multiple