Sql Rollback - HEIDENHAIN TNC 620 User Manual

Programming Q Parameters | Accessing tables with SQL commands

SQL ROLLBACK

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
SQL ROLLBACK discards all of the changes and additions of a
transaction. The transaction is defined via the HANDLE to be
specified.
The function of the SQL command SQL ROLLBACK depends on the
INDEX:
Without INDEX:
All changes and additions to the transaction are discarded
A lock that was set with SELECT...FOR UPDATE is canceled.
The transaction is concluded (the HANDLE loses its validity)
With INDEX:
Only the indexed row remains in the result set (all other
rows are removed)
Any changes and additions made in the rows that are not
specified are discarded
A lock that has been set with SELECT...FOR UPDATE
remains only for indexed row (all other locks are canceled)
The specified (indexed) row becomes the new row 0 of the
result-set
The transaction is not
validity)
It is necessary to later concluded the transaction using SQL
ROLLBACK or SQL COMMIT
Parameter No. for result (return value for the
control):
0 successful transaction
1 successful transaction
Database: SQL access ID: Define Q parameters
for the HANDLE (for identifying the transaction)
Database: Index to SQL result: Row that
remains in the result set
Program the row number directly
Program the Q parameter containing the
index
HEIDENHAIN | TNC 620 | Conversational Programming User's Manual | 10/2017
concluded (the HANDLE keeps its
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