dataEvent_record_BeforeDeleteRow

Function called before deleting a row.

Syntax

PUBLIC FUNCTION dataEvent_record_BeforeDeleteRow(
   uniqueKey record-type)
   RETURNS (INTEGER, STRING, uniqueKey)

The function has this parameter:

  1. uniqueKey. This is a RECORD type defined in the BAM-generated common file (my_entity_common.4gl). It includes the unique key fields from the schema of the database table.
It returns these values:
  1. An integer with the SQLCA.SQLCODE error number. Codes are defined as constants in the libdbappSql and libdbappCore libraries. The errors that are relevant to this function are shown in Table 1.
    Table 1. SQLCA.SQLCODE
    Description Constant Value
    Success ERROR_SUCCESS 0
    Failure ERROR_FAILURE -1
  2. A string is returned with the SQLERRMESSAGE error message.
  3. uniqueKey. This is a RECORD type defined in the BAM-generated common file (my_entity_common.4gl). It includes the unique key fields from the schema of the database table.

Usage

When you select the Before Delete Row property for the creation of the event, a function shell is created. Enter your code in the function.

This function is called before deleting a row in the database. For example, you can use this function to write the row of data to a backup table before the row is deleted.

Example: BeforeDeleteRow

This example uses the Before Delete Row code event for the Account table in the OfficeStore demo.

The row of data referenced by the variable uniqueKey is written to a backup table. It is assumed that you have created the backup table for account before saving the row to it.

PUBLIC FUNCTION dataEvent_recAccount_BeforeDeleteRow(uniqueKey recAccount_br_uk_type)
    RETURNS (INTEGER, STRING, recAccount_br_uk_type)

    DEFINE errNo INTEGER
    DEFINE errMsg STRING
    DISPLAY "dataEvent_recAccount_BeforeDeleteRow (Row scope) is raised"
    TRY
        INSERT INTO account_backup SELECT * FROM account
          WHERE @account.userid = uniqueKey.account_userid
    CATCH
        DISPLAY "SQL ERROR: ", SQLCA.SQLCODE
        LET errNo = ERROR_FAILURE
        LET errMsg = " - BeforeDeleteRow failed to insert in backup "
    END TRY
    DISPLAY "dataEvent_recAccount_BeforeDeleteRow (Row scope) is exited"

    RETURN errNo, errMsg, uniqueKey.*
END FUNCTION