Transaction

Demarcate or manage a JDBC transaction.

Component Signature

<bx:Transaction action=[string]
isolation=[string]
savepoint=[string]
nested=[boolean]
datasource=[string] />

Attributes

Atrribute	Type	Required	Description	Default
action	string	false	When used inside a transaction block, perform some action upon an existing transaction. One of: begin, commit, rollback, or setsavepoint.	begin
isolation	string	false	The isolation level to use for the transaction. Can only be set upon transaction begin. One of: read_uncommitted, read_committed, repeatable_read, or serializable.
savepoint	string	false	The name of the savepoint to set or rollback to. Used with savepoint or rollback actions.
nested	boolean	false	Whether or not this transaction is nested within another transaction. Default is false.	false
datasource	string	false	The name of the datasource to use for the transaction. If not provided, the first query execution inside the transaction will set the datasource.

Examples

Simple Transaction

A "simple" transaction might look like this:

transaction{
    queryExecute( "UPDATE users SET name=:name WHERE id=:id", { id: variables.id, name: variables.name } );
    queryExecute(
        "INSERT INTO userLog( action, id, changes ) VALUES ( 'UPDATE', :id, :change)",
        { id: variables.id, change: "changed name to #variables.name#" }
    );
}

Note that you can specify a custom isolation level using the isolation attribute on the component:

transaction isolation="serializable"{
    // ...
}

Nested Transaction

BoxLang supports nested transactions, using savepoints to control transaction state between the parent and child transactions.

transaction{
    queryExecute( "UPDATE users SET name=:name WHERE id=:id", { id: variables.id, name: variables.name } );

    transaction{
        try{
            queryExecute(
                "INSERT INTO userLog( action, id, changes ) VALUES ( 'UPDATE', :id, :change)",
                { id: variables.id, change: "changed name to #variables.name#" }
            );
        } catch( any e ){
            // user log errored; rollback!
            transactionRollback();
            // log error here
        }
    }
}

Here, we have a nested transaction that may (or may not) error; if this happens we want to roll back the logging query but NOT roll back the user query. This functions the same as if we were rolling back to a named savepoint created just after the UPDATE users query.

Script Syntax

Run Example

bx:transaction {
	try {
		// code to run
		bx:transaction action="commit";
	} catch (any e) {
		bx:transaction action="rollback";
	}
}

Tag Syntax

<bx:transaction> 
 <bx:try> 
 <!--- code to run ---> 
   <bx:transaction action="commit"/> 
  
 <bx:catch type="any"> 
 <bx:transaction action="rollback"/> 
 </bx:catch></bx:try> 
 </bx:transaction>