HEIDENHAIN TNC 620 (73498x-01) ISO programming - Manual (Page 248)

248 Programming: Q parameters
8.8 A
ccessing tables with SQL commands
SQL COMMIT
SQL COMMIT transfers all rows in the result set back to the table. A lock
set with SELECT...FOR UPDATE is canceled.
The handle given in the SQL SELECT command loses its validity.
U Parameter no. for result : Q parameter in which the
SQL server reports the result:
0: No error occurred.
1: Error occurred (incorrect handle or equal entries in
columns requiring unique entries)
U Data bank: SQL access ID : Q parameter with the
handle for identifying the result set (also see SQL
SELECT
)
SQL ROLLBACK
How SQL ROLLBACK is executed depends on whether INDEX is
programmed:
„ If INDEX is not programmed: The result set is not written back to the
table (any changes/insertions are discarded). The transaction is
closed and the handle given in the SQL SELECT command loses its
validity. Typical application: Ending a transaction solely containing
read-accesses.
„ If INDEX is programmed: The indexed row remains. All other rows
are deleted from the result set. The transaction is not concluded. A
lock set with SELECT...FOR UPDATE remains for the indexed row. For
all other rows it is reset.
U Parameter no. for result : Q parameter in which the
SQL server reports the result:
0: No error occurred.
1: Error occurred (incorrect handle)
U Data bank: SQL access ID : Q parameter with the
handle for identifying the result set (also see SQL
SELECT
)
U Data bank: Index for SQL result : Row that is to
remain in the result set. Either enter the row number
directly or program the Q parameter containing the
index
Example:
11 SQL BIND Q881 "TAB_EXAMPLE.MEAS_NO"
12 SQL BIND Q882 "TAB_EXAMPLE.MEAS_X"
13 SQL BIND Q883 "TAB_EXAMPLE.MEAS_Y"
14 SQL BIND Q884 "TAB_EXAMPLE.MEAS_Z"
. . .
20 SQL Q5 "SELECT MEAS_NO,MEAS_X,MEAS_Y,
MEAS_Z FROM TAB_EXAMPLE"
. . .
30 SQL FETCH Q1 HANDLE Q5 INDEX+Q2
. . .
40 SQL UPDATE Q1 HANDLE Q5 INDEX+Q2
. . .
50 SQL COMMIT Q1 HANDLE Q5
Example:
11 SQL BIND Q881 "TAB_EXAMPLE.MEAS_NO"
12 SQL BIND Q882 "TAB_EXAMPLE.MEAS_X"
13 SQL BIND Q883 "TAB_EXAMPLE.MEAS_Y"
14 SQL BIND Q884 "TAB_EXAMPLE.MEAS_Z"
. . .
20 SQL Q5 "SELECT MEAS_NO,MEAS_X,MEAS_Y,
MEAS_Z FROM TAB_EXAMPLE"
. . .
30 SQL FETCH Q1 HANDLE Q5 INDEX+Q2
. . .
50 SQL ROLLBACK Q1 HANDLE Q5