VALIDATE()

The VALIDATE() function validates a record against data integrity constraints.

Format

VALIDATE(fvar, id, data)

where

fvar	is the file variable associated with an open file.

id	is the id of the record being processed.

data	is the data record.

The VALIDATE() function allows an application to test whether the record in data satisfies the validation rules for the file open to fvar. If successful, the function returns True. Using VALIDATE() against a hashed file that has no constraints defined will also return True.

If the validation fails, VALIDATE() returns False and the STATUS() function can be used to determine why it failed. A status of zero indicates that the constraints rules were not met. The failing field number will be in @FNO and the corresponding field name will be in @FNAME. A non-zero status value indicates that some other error occurred such as the file being of an inappropriate type.

Example

The processing performed by the VERIFY.CONSTRAINTS command is essentially as below:

LOOP

READNEXT ID FROM ID.LIST ELSE EXIT

READ REC FROM DATA.F, ID THEN

IF NOT(VALIDATE(DATA.F, ID, REC)) THEN

DISPLAY ID : ' (FIELD ' : @FNO ; ')'

END

REPEAT