Database stored procedures, triggers, connections

stored procedure : A stored procedure is a compiled SQL statement.
1. Stored procedure because the SQL statement has been pre-programmed Yi, it runs faster.
2. The security and integrity of the data can be guaranteed. Stored procedures enable users who do not have permissions to access the database indirectly under control, thus guaranteeing the security of the data. Stored procedures allow related actions to occur together to maintain the integrity of the database.
3. You can reduce the amount of traffic on your network. The stored procedure is primarily run on the server, reducing the pressure on the client.
4: Stored procedures can accept parameters, output parameters, return single or multiple result sets, and return values. You can return the cause of the error to the program
5: Stored procedures can contain program flow, logic, and queries to the database. Data logic can also be encapsulated and hidden by entities.

Trigger : When the trigger condition is met, the trigger body of the trigger is automatically executed by the system.
Trigger time: Before,after. Trigger event: There are insert,update,delete three kinds. Trigger type: Row trigger, statement trigger

INNER JOIN, outer join difference?
An inner connection is a guarantee that all rows in two tables meet the conditions of the connection, but not the outer connection.
In an outer join, certain columns of dissatisfaction are also displayed, that is, only the rows of one of the tables are restricted, not the rows of the other table. Left-connected, right-connected, fully connected, three kinds of

Database stored procedures, triggers, connections