Vely logo install | documentation | examples | changelog
16.10.0 released May 10, 2023

Purpose: Begins database transaction.

begin-transaction [ <options> ] [ @<database> ] [ on-error-continue | on-error-exit ] [ error [ define ] <error> ] [ error-text [ define ] <error text> ]

This statement begins a database transaction. <options> is any additional options to database's BEGIN/START you wish to supply and must immediately follow begin-transaction.

Once you start a transaction with begin-transaction, you must either commit it with commit-transaction or rollback with rollback-transaction. If you do neither, your transaction will be rolled back once the request has completed and your program will stop with an error message. This is because opening a transaction and leaving without committing or a rollback is a bug in your program.  

You must use begin-transaction, commit-transaction and rollback-transaction instead of calling the BEGIN/COMMIT/END through run-query.
Optional <database> is specified in "@" clause and is the name of the database_config_file.
Error handling
The error code is available in  <error> variable in optional "error" clause - this code is always "0" if successful. The <error> code may or may not be a number but is always returned as a string value. <error> is allocated memory. In case of error, error text is available in optional "error-text" clause in <error text>, which is allocated memory.

"on-error-continue" clause specifies that request processing will continue in case of error, whereas "on-error-exit" clause specifies that it will exit. This setting overrides database-level on-error for this specific statement only. If you use "on-error-continue", be sure to check the error code.

<error> and <error text> can be created with optional "define".

Note that if database connection was lost, and could not be reestablished, the request will error out (see error_handling).
begin-transaction @mydb
run-query @mydb="insert into employee (name, dateOfHire) values ('%s', now())" : "Terry" no-loop
commit-transaction @mydb

See also
Database ( begin-transaction   commit-transaction   current-row   database_config_file   database_queries   delete-query   on-error   prepared_statements   query-result   rollback-transaction   run-query  )  SEE ALL (documentation)

Copyright (c) 2017-2023 Dasoftver LLC