7.10.1 CHECK_FOR Parameters
Refer to Specifying File Names in I/O Commands.
Refer to Specifying File Key Lists in I/O Commands.
Specifies the name of a field that is to receive the "return code" that results from the I/O operation.
If the default value of *STATUS is used the return code is placed into a special field called #IO$STS which can be referenced in the RDML program just like any other field.
If a user field is nominated to receive the return code it must be alphanumeric with a length of 2. Even if a user field is nominated the special field #IO$STS will still be updated.
For the values, refer to I/O Return Codes.
Specifies what action is to be taken if an I/O error occurs when the command is executed.
An I/O error is considered to be a "fatal" error. Some examples are file not found, file is damaged, file cannot be allocated. These types of errors stop the function from performing any processing at all with the file involved.
If the default value of *ABORT is used the function will abort with error message(s) that indicate the nature of the I/O error.
*NEXT indicates that control should be passed to the next command. The purpose of *NEXT is to permit you to handle error messages in the RDML, and then ABORT, rather than use the default ABORT. (It is possible for processing to continue for LANSA for i and Visual LANSA, but this is NOT a recommended way to use LANSA.)
ER returned from a database operation is a fatal error and LANSA does not expect processing to continue. The IO Module is reset and further IO will be as if no previous IO on that file had occurred. Thus you must not make any presumptions as to the state of the file. For example, the last record read will not be set. A special case of an IO_ERROR is when a trigger function is coded to return ER in TRIG_RETC. The above description applies to this case as well.
Therefore, LANSA recommends that you do NOT use a return code of ER from a trigger function to cause anything but an ABORT or EXIT to occur before any further IO is performed.
*RETURN specifies that in a program mainline control is to be returned to the caller and in a subroutine control is to be returned to the caller routine or the program mainline.
If none of the previous values are used you must nominate a valid command label to which control should be passed.
Specifies the action to be taken if a validation error was detected by the command.
A validation error occurs when information that is to be added, updated or deleted from the file does not pass the FILE or DICTIONARY level validation checks associated with fields in the file.
If the default value *LASTDIS is used control will be passed back to the last display screen used. The field(s) that failed the associated validation checks will be displayed in reverse image and the cursor positioned to the first field in error on the screen.
*NEXT indicates that control should be passed to the next command.
*RETURN specifies that in a program mainline control is to be returned to the caller and in a subroutine control is to be returned to the caller routine or the program mainline.
If none of the previous values are used you must nominate a valid command label to which control should be passed.
The *LASTDIS is valid even if there is no "last display" (such as in batch functions). In this case the function will abort with the appropriate error message(s).
When using *LASTDIS the "Last Display" must be at the same level as the database command (INSERT, UPDATE, DELETE, FETCH and SELECT). If they are at different levels e.g. the database command is specified in a SUBROUTINE, but the "Last Display" is a caller routine or the mainline, the function will abort with the appropriate error message(s).
The same does NOT apply to the use of event routines and method routines in Visual LANSA. In these cases, control will be returned to the calling routine. The fields will display in error with messages returned to the first status bar encountered in the parent chain of forms, or if none exist, the first form with a status bar encountered in the execution stack (for example, a reusable part that inherits from PRIM_OBJT).
Specifies what is to happen if no record is found in the file that has a key matching the key nominated in the WITH_KEY parameter.
*NEXT indicates that control should be passed to the next command.
*RETURN indicates that control should be returned to the invoking routine (identical to executing a RETURN command).
If none of the previous values are used you must nominate a valid command label to which control should be passed.
Specifies whether a "not found" message is to be automatically issued or not.
The default value is *NO which indicates that no message should be issued.
The only other allowable value is *YES which indicates that a message should be automatically issued. The message will appear on line 22/24 of the next screen format presented to the user or on the job log of a batch job.