Creates a table access variable (a file handle).
Open["DICT",] expression To table_var Then Else statements
The Open statement has the following parameters.
| Parameter | Description |
|---|---|
| expression | Designates the native table that is to be opened. To open the dictionary, use DICT as the first part of the table name (example: "DICT.CUSTOMERS"); and to open the data portion of the table, use only the table name (example: "CUSTOMERS"). Use separate Open statements to open the DICT and data portions of each table. |
| table_var | After a successful Open operation, table_var contains information about the table. From that point on, refer to the table with table_var, not with the actual table name. |
| Then | The statement(s) following Then are executed if a table is opened successfully. |
| Else | The statement(s) following Else are executed if the table cannot be opened. The Status() function indicates the severity of the error, and the system variable @FILE_ERROR contains detail about the nature of the error. |
You must Open a table before attempting to Read or Write rows from/to that table. As long as a table has been opened once, it does not need to be opened again each time you want to Read or Write to it.
Each table must be opened with a separate Open statement. Any number of tables may be opened at any point in the program.
Tables opened with the Open command need not and cannot be closed.|
/* The following program demonstrates file opening and subsequent processing. */
table = "CAR_PARTS"
Open table To tablevar Then
Open "DICT", table To @DICT Else null
End Else
* error processing: cannot open table
End
Select tablevar
Done = 0
Printer On
Loop
ReadNext @ID Else done = 1
Until done
Read @RECORD From tablevar, @ID Then
report = {PART_NAME}:" ":{PART_TYPE}:" ":{PART_NO}
Print report
End
Repeat
Printer Off