OPEN command

Used to open an ACL table and the associated data file.

Syntax

OPEN {table_name|data_file} <FORMAT layout_name> <BUFFERLENGTH length>
<CRLF> <DBASE> <INDEX index_file> <PRIMARY|SECONDARY> <SKIP bytes>
<RELATION key_field>

Parameters

table_name

Specifies the name of the ACL table to open.

data_file

The data file to associate with the table specified by the FORMAT parameter. ACL assumes a file extension of .fil if no extension is specified. To open a file with no extension, insert a period (.) at the end of the file name.

FORMAT layout_name

Optional. Specifies which ACL table layout to apply to the ACL table that you open.

BUFFERLENGTH n

Optional. Specifies the length (in bytes) of the input buffer area to be allocated to the table. Larger buffer areas may improve processing speed at the expense of RAM available for storing ACL commands.

If any IBM variable length blocks are read which exceed the buffer length, ACL displays an error message and stops processing. The default value is set in the Buffer Size field in the Table tab in the Options dialog box.

You will seldom need to change this parameter, because the default is sufficient to handle almost all situations. The default value is 33,000 bytes.

CRLF

Optional. Specifies that a variable length ASCII file is to be read. ACL automatically adjusts for the varying record lengths. By default, files are assumed to be fixed-length files.

DBASE

Optional. Specifies that the data source is a dBASE file. ACL recognizes the type of dBASE file and automatically creates a table from the file description. This parameter can be omitted for dBASE files with a .dbf extension.

INDEX index_file

Optional. Specifies the index file to apply to the table when it is opened. The file extension for the index file name is assumed to be .inx when none is specified. You can specify INDEX with either primary or secondary tables.

PRIMARY | SECONDARY

Optional. Specifies that a table is opened as either a primary table or a secondary table. If the parameter is omitted, the table is opened as a primary table.

SKIP bytes

Optional. Specifies the number of bytes to bypass at the physical start of the table. SKIP can be used to ignore table header records or leading portions of the table which do not follow the layout of the remainder of the table. If this parameter is omitted, the table is read starting at the first byte.

RELATION key_field

Optional. Specifies that the table is to be opened as an ad hoc related table. ACL does not retain this relation when the table is closed. You must also specify the INDEX parameter when you use the RELATION parameter. The key_field value is the key field or expression ACL uses to create the relation between two tables.

Examples

a. Open a table while specifying a table layout

The following example opens the April_2012 table using the March_2012 table layout:

OPEN April_2012 FORMAT March_2012

b. Open a dBASE file

The following example opens a dBASE file named Inventory.dbf for which there is no existing table.

OPEN Inventory

c. Open a table and apply a pre-existing index

To open either a primary or a secondary table, and apply an index that already exists for the table, use the following syntax:

OPEN Accounts_receivable INDEX Customer_number_AR

OPEN Customer SECONDARY INDEX Customer_number

d. Open a table and establish an ad hoc relation to another table

To establish a temporary relation between an open table named Customers (the primary table) and a table named Accounts_receivable (the secondary table), using an index named Customer_index, and a key field in the primary table named Last_name, use the following syntax:

OPEN Accounts_receivable INDEX Customer_index RELATION Last_name



(C) 2015 ACL Services Ltd. All Rights Reserved.