1. Storage process and overview
ORACLE can store PL/SQL programs in the database and run them anywhere. This is called a stored procedure or function. Procedures and functions , collectively known as PL/SQL subroutines and named PL/SQL blocks, are stored in the database and exchange information with their callers through input and output parameters or input/output parameters. The only difference between procedures and functions is that functions always return data to the caller, while procedures do not.
1.1. Create a stored procedure statement
create [or replace] procedure stored procedure name [(parameter in|out|in out parameter data type,...)]
is|as
reputation part;
begin
plsql code block;
exception
Exception handling;
end;
1.2. Calling stored procedures
1. Call in plsql block
Write the name directly
2.call command call
call stored procedure name();
3.execute command call
Execute on the console. If you do not want to print the result, you need to run set serveroutput on;
1.3. Delete stored procedures
drop procedure stored procedure name;
1.4. Three modes of stored procedure parameters
IN is used to accept the value of the calling program. Default parameter mode
OUT is used to return a value to the calling program
IN OUT is used to accept the value of the caller and return the updated value to the caller
2. Function
2.1. Statements to create functions
create [or replace] function function name [(formal parameter parameter type,...)]
return return value type
is
claim variable;
begin
plsql code block;
return return value;
end;
2.2. How to access functions
1. Use SQL statements
select function name from dual;
2. Using PL/SQL blocks
declare
v varchar2(30);
begin
v:=f1;
dbms_output.put_line(v);
end;