HEIDENHAIN TNC 620 (73498x-01) ISO programming - Manual (Page 243)

HEIDENHAIN TNC 620 243
8.8 A
ccessing tables with SQL commands
SQL SELECT
SQL SELECT selects table rows and transfers them to the result set.
The SQL server places the data in the result set row-by-row. The rows
are numbered in ascending order, starting from 0. This row number,
called the INDEX, is used in the SQL commands "Fetch" and "Update."
Enter the selection criteria in the SQL SELECT...WHERE... function.
This lets you restrict the number of rows to be transferred. If you do
not use this option, all rows in the table are loaded.
Enter the sorting criteria in the SQL SELECT...ORDER BY... function.
Enter the column designation and the keyword for
ascending/descending order. If you do not use this option, the rows
are placed in random order.
Lock out the selected rows for other applications with the SQL
SELECT...FOR UPDATE
function. Other applications can continue to read
these rows, but cannot change them. We strongly recommend using
this option if you are making changes to the table entries.
Empty result set: If no rows match the selection criteria, the SQL
server returns a valid handle but no table entries.