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Can we use select statement in trigger?
The trigger event that initiates the trigger action can be an INSERT, DELETE, UPDATE, or a SELECT statement. You can use the CREATE TRIGGER statement in two distinct ways: You can define a trigger on a table in the current database. You can also define an INSTEAD OF trigger on a view in the current database.
What is triggers in SQLite?
A trigger is a named database object that is associated with a table, and it activates when a particular event (e.g. an insert, update or delete) occurs for the table/views. The statement CREATE TRIGGER creates a new trigger in SQLite. The CREATE TRIGGER statement is used to add triggers to the database schema.
What is select in SQLite?
SQLite SELECT statement is used to fetch the data from a SQLite database table which returns data in the form of a result table. These result tables are also called result sets.
What is a trigger statement?
A trigger defines a set of actions that are executed when a database event occurs on a specified table. For example, if you define a trigger for a delete on a particular table, the trigger’s action occurs whenever someone deletes a row or rows from the table. …
Does SQLite have stored procedures?
SQLite does not provide the stored procedure concept; basically, stored procedure means we can prepare a single code, and that code we can reuse again and again as per user requirement. But we can use stored procedures in SQLite in a different way, that is, by creating a temporary single-row table.
How do I SELECT from SQLite?
To select data from an SQLite database, use the SELECT statement. When you use this statement, you specify which table/s to select data from, as well as the columns to return from the query. You can also provide extra criteria to further narrow down the data that is returned.
What do you need to know about SQLite trigger?
Summary: this tutorial discusses SQLite trigger, which is a database object fired automatically when the data in a table is changed. An SQLite trigger is a named database object that is executed automatically when an INSERT, UPDATE or DELETE statement is issued against the associated table.
How does the SELECT statement work in SQLite?
After execution of the select statement result will be zero or more rows from the table. The select statement just retrieves the data that means it is read-only by command and it does not make any changes to the database.
What happens when you omit the when clause in SQLite?
If you use a condition in the WHEN clause, the trigger is only invoked when the condition is true. In case you omit the WHEN clause, the trigger is executed for all rows. Notice that if you drop a table, all associated triggers are also deleted.
How does the audit trial work in SQLite?
To keep audit trial, we will create a new table called AUDIT where the log messages will be inserted, whenever there is an entry in COMPANY table for a new record. Here, ID is the AUDIT record ID, and EMP_ID is the ID which will come from COMPANY table and DATE will keep timestamp when the record will be created in COMPANY table.