в 13:45, 26 мая 2010

2010-05-26T13:45:46Z

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2010-05-26T10:04:45Z

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== DEREF operator==



<source lang="sql">
SQL>
SQL>
SQL>
SQL> CREATE OR REPLACE TYPE address AS OBJECT
2 (line1 VARCHAR2(20),
3 line2 VARCHAR2(20),
4 city VARCHAR2(20),
5 state_code VARCHAR2(2),
6 zip VARCHAR2(13),
7 MEMBER FUNCTION get_address RETURN VARCHAR2,
8 MEMBER PROCEDURE set_address
9 (addressLine1 VARCHAR2,
10 addressLine2 VARCHAR2,
11 address_city VARCHAR2,
12 address_state VARCHAR2,
13 address_zip VARCHAR2)
14 );
15 /
Type created.
SQL> CREATE OR REPLACE TYPE BODY address AS
2 MEMBER FUNCTION get_address RETURN VARCHAR2
3 IS
4 BEGIN
5 RETURN (SELF.line1||" "||SELF.line2||" "||SELF.city||", "|| SELF.state_code||" "||SELF.zip);
6 END get_address;
7 MEMBER PROCEDURE set_address (addressLine1 VARCHAR2,
8 addressLine2 VARCHAR2,
9 address_city VARCHAR2,
10 address_state VARCHAR2,
11 address_zip VARCHAR2)
12 IS
13 BEGIN
14 line1 :=addressLine1;
15 line2 :=addressLine2;
16 city :=address_city;
17 state_code :=address_state;
18 zip :=address_zip;
19 END set_address;
20 END;
21 /
Type body created.
SQL>
SQL>
SQL> CREATE TABLE employee(
2 empid number(10)PRIMARY KEY,
3 lastname varchar2(30)NOT NULL,
4 firstname varchar2(30)NOT NULL,
5 middle_initial varchar2(2),
6 emp_address REF address);
Table created.
SQL>
SQL>
SQL> DECLARE
2 addressValue_ref REF address;
3 addressValue address;
4 BEGIN
5 SELECT DEREF(addressValue_ref)
6 INTO addressValue
7 FROM DUAL;
8 END;
9 /
PL/SQL procedure successfully completed.
SQL> DECLARE
2 addressValue address;
3 BEGIN
4 SELECT DEREF(e.emp_address) INTO addressValue FROM employee e WHERE e.lastname ="LAKSHMAN";
5
6 DBMS_OUTPUT.PUT_LINE(addressValue.line1||" "||addressValue.line2);
7
8 DBMS_OUTPUT.PUT_LINE(addressValue.city||", "||addressValue.state_code||" "|| addressValue.zip);
9
10 END;
11 /
DECLARE
*
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 4

SQL>
SQL> UPDATE employee SET emp_address =NULL WHERE emp_address IS DANGLING;
0 rows updated.
SQL>
SQL> drop table employee;
Table dropped.
SQL></source>

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Oracle PL/SQL Tutorial/Object Oriented/DEREF function - История изменений

в 13:45, 26 мая 2010

Admin: 1 версия