It has not yet supported the FOR EACH STATEMENT triggers.
If the trigger associated with the table is fired one time, we call this trigger a FOR EACH STATEMENT trigger.Īs of version 3.9.2, SQLite only supports FOR EACH ROW triggers. This trigger is called FOR EACH ROW trigger.
#Net sqlite transaction update#
Suppose you use a UPDATE statement to update 10 rows in a table, the trigger that associated with the table is fired 10 times. If you combine the time when the trigger is fired and the event that causes the trigger to be fired, you have a total of 9 possibilities:
Finally, place the trigger logic in the BEGIN END block, which can be any valid SQL statements. After that, indicate the table to which the trigger belongs. Then, specify the event that causes the trigger to be invoked such as INSERT, UPDATE, or DELETE. However, you can only create an INSTEAD OF trigger on a view. You can create BEFORE and AFTER triggers on a table. Next, determine when the trigger is fired such as BEFORE, AFTER, or INSTEAD OF. First, specify the name of the trigger after the CREATE TRIGGER keywords. ĮND Code language: SQL (Structured Query Language) ( sql ) To create a new trigger in SQLite, you use the CREATE TRIGGER statement as follows: CREATE TRIGGER trigger_name In addition, you use triggers to enforce complex business rules centrally at the database level and prevent invalid transactions. For example, you want to log the changes in the sensitive data such as salary and address whenever it changes. You often use triggers to enable sophisticated auditing. What is an SQLite triggerĪn SQLite trigger is a named database object that is executed automatically when an INSERT, UPDATE or DELETE statement is issued against the associated table. Summary: this tutorial discusses SQLite trigger, which is a database object fired automatically when the data in a table is changed.
0 kommentar(er)
