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
Accessing tables with SQL commands
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TNC 320 | User's Manual HEIDENHAIN Conversational Programming | 5/2013
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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.