HEIDENHAIN TNC 620 (340 56x-03) ISO programming - Manual (Page 230)

230 Programming: Q Parameters
8.8 A
c
cessing T
a
bles with SQL Commands
8.8 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.
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.
„ 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.
Tables are configured by the machine manufacturer.
Names and designations required as parameters for SQL
commands are also specified.