Storage structure of MySQL database

--Encapsulate several SQL statements, a name called a procedure, and a function that has no return value--storing the process in a database--stored procedure

--the creation process of the stored procedure create PROCEDURE Proceducename () Beginsql statement end$--View Show procedure status \g--Invoke Call ProcedureName () $--  Declaring variable declare age int default 18;--operation set age:=age+10;--changing bounds delimiter $--example CREATE PROCEDURE P1 () Begindeclare age int Default 18;set age:=age+10;select age;end$--with Call P1 () $ Called when age    28 occurs

--CREATE TABLE test (ID int,name varchar () NOT NULL default ", age int,content varchar ()) Engine MyISAM CharSet utf8$ Inserting data insert into test values (1, ' Zhangsan ', 13, ' learning Good '), (2, ' Lisi ', 15, ' incarnation of Wisdom '), (2, ' Wangwu ', 14, ' humble ') $

--Stored Procedure Store SQL statements CREATE PROCEDURE P2 () Beginselect content from test where age=15;end$--stored procedures can be programmed-meaning you can use variables, expressions, Control structure complete complex function--if/else statement using if condition then statement; else if condition then statement; Else statement; end If;create Procedure P3 () Begindeclare age int Default 1 8;if age>=18 thenselect ' You have grown up '; Elseselect ' underage '; end If;end$--while Loop while conditional do statement; End while;--parentheses can declare parameters--parameter types [in/  Out/inout] Parameter Name argument type CREATE PROCEDURE P4 (Agee int) Beginselect name from test where age=agee;end$in indicates input parameter argument out indicates output parameter pass variable name Outgoing value to set the initialization value inout the input parameter is executed and the output passes in a declared variable name, create procedure P5 (in age int) Beginselect as ' You are a few years old '; End$--out parameter, to initialize parameters inside procedure CREATE PROCEDURE P6 (out result int) begindeclare i int default 1;set result:=0;while i<= Doset Result:=result+i;set i:=i+1;end while;end$--calls call P6 (@num) $select @num $--inout Parameters CREATE PROCEDURE P7 (inout Age int) Beginset Age:=age+10;select ages as ' 10 years later you're a few years old '; End$set @age =10$call P7 (@age) $select @age $--case statement case variable name when value 1 t Hen operation 1;when Value 2 then operation 2;...else Operation N;end Case;--repeat loop repeat operatorSentence until condition end repeat; 

Storage structure of MySQL database