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Programming Q Parameters | Accessing tables with SQL commands
10
HEIDENHAIN | TNC 640 | Conversational Programming User's Manual | 10/2017
449
SQL SELECT
SQL SELECT
reads a single value from a table and saves the result
in the defined Q parameter.
You can select multiple values or columns using the SQL
command
SQL EXECUTE
and the
SELECT
instruction.
Further information: "SQL EXECUTE", page 441
With
SQL SELECT
, there is neither a transaction nor binding
between the table columns and Q parameter. Any existing bindings
to the specified columns are not taken into consideration; only the
read-out value is copied into the parameter specified for the result.
Example: Reading and saving a value
20 SQL SELECT Q5 "SELECT Meas_X FROM Tab_Example WHERE
MEAS_NO==3"
Parameter No. for result
: Q parameter for
saving the value
Database: SQL command text
: Programming
SQL instruction
SELECT
with the table column of the value to
be transferred
FROM
with a table’s synonym or path (place
the path in single quotation marks)
WHERE
with column designation, condition
and comparison value (Q parameter after
:
in
single quotation marks)
The result of the subsequent NC program is identical to the
application example shown previously.
Further information: "Application example", page 439
Example
0 BEGIN PGM SQL MM
1 SQL SELECT QS1800 "SELECT WMAT FROM my_table
WHERE NO==3"
Read and save a value
2 END PGM SQL MM