> ## Documentation Index
> Fetch the complete documentation index at: https://docs.arc.cdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# dbBeginTransaction

> Executes the BEGIN TRANSACTION SQL command to mark the start of an explicit SQL transaction.

export const siteNameShort = "Arc";

Executes the `BEGIN TRANSACTION` SQL command. Indicates the start point of an explicit SQL transaction. Use this operation in tandem with [dbEndTransaction](./op-db-end-transaction) where other database operations are executed between calls to dbBeginTransaction and dbEndTransaction. See the [Example](#example) for more information.

## Required Parameters

* **driver**: The JDBC driver class name in the cross-platform edition or the ADO.NET provider name in the .NET edition.
* **conn**: The connection string or database URL.

## Optional Parameters

* **transactiontimeout**: Timeout, in seconds, of this transaction. Zero (`0`) means no timeout. The default is `60`.
* **transactionid**: The Id of the transaction. If not set, {siteNameShort} generates a GUID to use as the transaction Id.

## Output Parameters

* **transactionid**: The Id of the transaction.

## Example

In this example, database queries are executed between dbBeginTransaction and dbEndTransaction, creating a SQL transaction. To determine the status of the transaction, the status of each query is checked. If all queries are successful, commit the transaction; otherwise roll back the transaction.

```xml theme={null}
<!-- Creating the input item and defining the SQL queries -->
<arc:set attr="db.driver" value="cdata.jdbc.mysql.MySQLDriver" />
<arc:set attr="db.conn" value="jdbc:cdata:mysql:server=localhost;port=3306;database=sakila;user=root;password=Password123;"/>
<arc:set attr="db.transactionaction" value="COMMIT" />
<arc:set attr="sql.queries#" value="ALTER TABLE Colors ADD Example varchar(255);"/>
<arc:set attr="sql.queries#" value="INSERT INTO Colors VALUES (27, Blue, Sky);" />
<arc:set attr="sql.queries#" value="INSERT INTO Colors VALUES (28, Red, Apple);" />
<arc:set attr="sql.queries#" value="INSERT INTO Colors VALUES (29, Yellow, Banana);" />

<arc:call op="dbBeginTransaction" in="db" out="dbbeginout">
  <arc:try>
    <!-- Enumerate and execute all queries and set the transactionaction based on the result -->
    <arc:enum attr="sql.queries">
      <arc:set attr="db.query" value="[_value]"/>
      <arc:call op="dbNonQuery" in="db" out="results" >
        <arc:set attr="db.transactionaction" value="[results.db:result | equals('success', 'COMMIT', 'ROLLBACK')]" />
      </arc:call>
      <!-- If any queries were flagged as rollback, stop running the queries -->
      <arc:if exp="[db.transactionaction | equals('ROLLBACK')]">
        <arc:break />
      </arc:if>
    </arc:enum>
    <!-- If any exception is raised, catch it and set the transactionaction to rollback -->
    <arc:catch>
      <arc:set attr="db.transactionaction" value="ROLLBACK" />
    </arc:catch>
    <!-- Finally, call dbEndTransaction to either commit or roll back the SQL transaction -->
    <arc:finally>
      <arc:set attr="db.transactionid" value="[dbbeginout.transactionid]" />
      <arc:call op="dbEndTransaction" in="db" />
    </arc:finally>
  </arc:try>
</arc:call>
```

You can modify the example above to target other databases as long as the driver is installed on the machine where {siteNameShort} is installed and running. Adjusting this example for .NET involves changing the `driver` and `conn` inputs as follows:

```xml theme={null}
<arc:set attr="db.driver" value="System.Data.CData.MySql" /> 
<arc:set attr="db.conn" value="Server=localhost;Database=sakila;UID=root;Password=Password123;"/>
```