db_transaction Execute database statements within a transaction
package require nstcl-database ?1.0?
package require nstcl ?1.0?
::nstcl::db_transaction code? on_error on_error_code?
db_transaction evalutates code inside of a database transaction. An optional on_error_code can be specified which is evaluated each time there is an error. The on_error_code may choose to let the transaction continue by calling db_continue_transaction. If the transaction is not explicitly continued (or if there is no on_error_code specified) then the transaction is aborted, and the database is rolled back to the state it was before the transaction began.