Database advanced learning notes - storage structure

--1. What is stored procedure
One by one PLSQL Business processing procedures are stored and reused , These are stored PLSQL Programs are called stored procedures

--2. Syntax of stored procedure
grammar :
create or replace procedure Process name ( Parameters ) is
begin
end;

--3. Notes on stored procedures
1. There was no declare keyword ,declare Used in a statement block

2.：is and as Is interoperable , It doesn't matter which one you use  

--4. classification
No parameters 、   With input parameters   、 With output parameters ( Return value ) Of   、   With input and output parameters ( Return value ) Of
3.1 No parameters
create or replace procedure pro_name101 as
begin
dbms_output.put_line(' Stored procedure review ');
end;
-- call
begin
pro_name101;
end;

3.2 With input parameters
create or replace procedure pro_name102(v_deptno in emps.deptno%type) is
v_ename emps.ename%type;
begin
select ename into v_ename from emps where deptno=v_deptno;
dbms_output.put_line(v_ename);
end;

-- call
begin
pro_name102(10);
end;

3.3 With output parameters ( Return value ) Of  
create or replace procedure pro_name103(v_ename out emps.ename%type) is
begin
select ename into v_ename from emps where empno=7788;
end;

-- call
declare
v_ename1 emps.ename%type;
begin
pro_name103(v_ename1);
dbms_output.put_line(v_ename1);
end;

3.4 With input and output parameters ( Return value ) Of .
create or replace procedure pro_name104(v_empno in emps.empno%type,v_ename out emps.ename%type) is
begin
select ename into v_ename from emps where empno=v_empno;
end;

-- call
declare
v_empno1 emps.empno%type;
begin
pro_name104(7788,v_empno1);
dbms_output.put_line(v_empno1);
end;