C # database access through transactions

(C # transaction)

1. Create the transaction structure

Sqlconnection = new sqlconnection ();
... Initialize the connection

// Start the transaction
Sqltransaction =
Sqlconnection. begintransaction ();
// Apply the transaction to the command
Sqlcommand
Sqlcommand = new sqlcommand ();
Sqlcommand. Connection =
Sqlconnection;
Sqlcommand. Transaction = sqltransaction;

Try
{
// Use sqlcommand to perform data operations
...
// Submitted successfully

Sqltransaction. Commit ();
}
Catch (exception ex)
{

// Error rollback
Sqltransaction. rollback ();
}

2. Simple Example

{
Datatable dt = new
Datatable ();

System. Data. sqlclient. sqlconnection CNN = new
System. Data. sqlclient. sqlconnection ("connection string ");

System. Data. sqlclient. sqlcommand CM = new
System. Data. sqlclient. sqlcommand ();

Cm. Connection = CNN;
CNN. open ();

System. Data. sqlclient. sqltransaction trans =
CNN. begintransaction ();
Try

{
Foreach (datarow DR in
DT. Rows)

{
Cm. commandtext = "Update
[Table] Set [quantity] = @ amount where productid = @ productid ";


Cm. Parameters. Add ("@ amount", sqldbtype. INT );

Cm. Parameters ["@ amount"]. value = convert. toint32 (Dr ["amount"]);


Cm. Parameters. Add ("@ productid", sqldbtype. varchar );

Cm. Parameters ["@ productid"]. value =
Dr ["productid"]. tostring ();

Cm. executenonquery ();
}

Trans. Commit ();
}

Catch
{

Trans. rollback ();

}
Finally
{

CNN. Close ();

Trans. Dispose ();

CNN. Dispose ();
}
}

3. SQL Server transaction example

Begin transaction
Save transaction

Insert into demo values ('bb ',' B terminologies ')
Rollback
Transaction

Create Table demo2 (name varchar (10), age INT)
Insert
Demo2 (name, age) values ('Lis ', 1)
Rollback transaction

Insert into demo values ('bb', 'B
Term ')

Commit transaction

Commit transaction

4. Note

1. The transaction must begin intransaction () after the connection is opened ();

2. Add a transaction to sqlcommand (sqlcommand. Transaction =
Sqltransaction ;)

3. make corresponding adjustments for other databases

4. You can use a DLL provided by Microsoft, which is very convenient.