Unit 3(rdbms)

 Cursors : OPEN CLOSE and FETCH
 Creation of User Defined Function
 Creation of Stored Procedure

 Types of cursor
 Cursor Predicates
 Referencing cursor variable
 Code

 Function : A function is a logical grouped set of
SQL/PL statement that perform a specific task.

 PL/SQL functions are created by executing the

CREATE FUNCTION statement.

 Such functions can be dropped from the database by
using the DB2 SQL DROP statement.

 Drop function Func_name;

Create or replace function function_name (var1
datatype,var2 datatype) returns datatype

language SQL contains|reads|modifies sql data

Begin

………SQL PL code………..

return <value>;

End;

create or replace function simple_function()

returns varchar(10)

begin

return 'hello';

end;

;

 Create or replace function bonus(salary
int, bonus int)

returns int

return salary*bonus/100

Example

create or replace function create_table() returns int

language sql modifies sql data

begin

create table st(id int, name varchar(10), salary
numeric(10));

return 0;

end;

 Function also used to return table.

 Code
 Function_get.txt

 Stored Procedure is a logical grouped set
of SQL/PL statement that perform a
specific task.

 It can help to improve application
performance and reduce database access
traffic.

 Support procedural construct in high level PL
like C, c++ and java etc.

 Are stored in databases and run on DB2
server.

 Easily call whenever required(call statement)

 Reduce network usage between client and server.

 Enhance capabilities
 Increase memory disk space on the server

 Improve security
 User can call stored procedure but do not required.

 Reduced development cost.

 Centralized security and maintenance.

Create or replace procedure procedure_name

(in | out | inout arg1 type1,

in | out | inout arg2 type2,………)

Language SQL contains SQL

Begin

……statement…..

End

 Create procedure name:
 It define name of store procedure.

 What the name and data types of argument.

 In – input variable.

 Out – output variable.

 inout – both input and output.

 Language SQL contains sql
 Option can be
 Reads SQL data
 Contains SQL data
 Modifies SQL data

 Begin ….End statement
 Logic of store procedure

 Code

 Create Procedure p()
 BEGIN DECLARE C1 cursor;
 DECLARE varInt INT;
 SET count = -1;
 SET c1 = CURSOR FOR SELECT c1 FROM t1;
 IF (c1 IS NOT OPEN) THEN OPEN c1;
 ELSE set count = -2; END IF;
 set count = 0;
 IF (c1 IS OPEN) THEN
 FETCH c1 into varInt;
 WHILE (c1 IS FOUND) DO
 SET count = count + 1;
 FETCH c1 INTO varInt;
 END WHILE;
 ELSE SET count = 0;
 END IF;
 END@

 CREATE PROCEDURE
ADMINISTRATOR.UPDATE_SAL (IN empNum
CHAR(6), IN rating SMALLINT)

 LANGUAGE SQL
 BEGIN
 IFrating = 1 THEN
 UPDATE employee
 SET salary = salary * 1.10,
 bonus = 1500 WHERE empno = empNum;
ELSE UPDATE employee
 SET salary = salary * 1.05, bonus = 1000
WHERE empno = empNum;
 END IF;
 END

Unit 3(rdbms)

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Unit 3(rdbms)