Description:
Roll back a database transaction.
Syntax:
db.rollback (spn)
Note:
The function rolls back the transaction to the specified savepoint. Rollback all transactions when the parameter is omitted.
Parameter:
|
db |
Database connection |
|
spn |
Savepoint name |
Example:
|
|
A |
B |
|
|
1 |
=create(ID,NAME,GENDER,AGE).record([3, "AAA","F",14]) |
|
|
|
2 |
=connect@e("demo") |
|
Establish a connection and use @e option to automatically control the commit and rollback operations. |
|
3 |
=A2.savepoint("s1") |
|
set the savepoint named s1. |
|
4 |
>A2.execute@k(A1,"update STUDENTS2 set NAME=?,GENDER=?,AGE=? where ID=?",NAME,GENDER,AGE,ID) |
|
Execute the sql statement, update table STYDENTS2 according to A1’s records, and use @k option to not to commit the transaction. |
|
5 |
=A2.error() |
|
Get the error code generated from the execution of the previous SQL statement. |
|
6 |
if A5==0 |
>A2.commit() |
Commit if there is not an error. |
|
7 |
else |
>A2.rollback("s1") |
Roll back if there is an error. |
|
8 |
>A2.close() |
|
Close the connection. |
Related function: