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9 accessing tables with sql commands, Introduction, Accessing tables with sql commands – HEIDENHAIN TNC 320 (34055x-06) User Manual

Page 269: Accessing tables with sql commands 8.9

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Accessing tables with SQL commands

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TNC 320 | User's Manual HEIDENHAIN Conversational Programming | 5/2013

269

8.9

Accessing tables with SQL commands

Introduction

Accessing of tables is programmed on the TNC with SQL
commands in

transactions

. A transaction consists of multiple SQL

commands that guarantee an orderly execution of the table entries.

Tables are configured by the machine manufacturer.
Names and designations required as parameters for
SQL commands are also specified.

The following

terms

are used:

Table

: A table consists of x columns and y rows. It is saved as

a file in the File Manager of the TNC, and is addressed with the
path and file name (=table name). Synonyms can also be used
for addressing, as an alternative to the path and file name.

Columns

: The number and names of the columns are specified

when configuring the table. In some SQL commands the
column name is used for addressing.

Rows

: The number of rows is variable. You can insert new

rows. There are no row numbers or other designators. However,
you can select rows based on the contents of a column. Rows
can only be deleted in the table editor, not by an NC program.

Cell

: The part of a column in a row.

Table entry

: Content of a cell.

Result set

: During a transaction, the selected columns and

rows are managed in the result set. You can view the result set
as a sort of "intermediate memory," which temporarily assumes
the set of selected columns and rows. Result set

Synonym

: This term defines a name used for a table instead of

its path and file name. Synonyms are specified by the machine
manufacturer in the configuration data.