Sql Rollback - HEIDENHAIN TNC 620 User Manual

Programming Q parameters | Accessing tables with SQL statements

SQL ROLLBACK

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:
The control discards all changes and additions of the
transaction
The control resets a lock set with SELECT...FOR UPDATE
The control completes the transaction (the HANDLE loses its
validity)
With INDEX:
Only the indexed row remains in the result set (the control
removes all of the other rows)
The control discards any changes and additions that may
have been made in the non-specified rows
The control locks only those rows indexed with SELECT...FOR
UPDATE (the control resets all of the other locks)
The specified (indexed) row is then the new Row 0 of the
result set
The control does not complete the transaction (the HANDLE
keeps its validity)
The transaction must be completed manually with SQL
ROLLBACK or SQL COMMIT at a later time
Example for the SQL ROLLBACK command
Remarks:
The gray arrows and associated syntax do not directly belong to
the SQL ROLLBACK command
Black arrows and associated syntax indicate internal processes of
SQL ROLLBACK
Define Parameter number for result (return
values for the control):
0: Transaction successful
1: Transaction failed
Database: SQL access ID: Define Q parameter for
the HANDLE (for identifying the transaction)
Define Database: Index for SQL result (row that
remains in the result set)
Row number
Q parameter with the index
HEIDENHAIN | TNC 620 | Klartext Programming User's Manual | 01/2022
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