一、記錄和集合概述

???????? 目前為止所介紹的變量的數據類型都屬于scalar，即標量，如×××，字符串，日期等等。任何一種編程語言都需要提供一些手段讓用戶創建更復雜的變量，PL/SQL也不例外，本章就來介紹一下PL/SQL中的復合型變量。

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PL/SQL的復合型變量主要包括兩類：

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????????????? 1. Records：記錄

????????????? 2. Collection：集合。Collection又可以分為三種，

????????????????????????????? a. Associative? Array（INDEXTBY table）: 關聯數組（或稱索引表，和SQL中的INDEX OF TABLE不是一個概念）

????????????????????????????? b. Nested Table: 嵌套表

????????????????????????????? c. Varray: 可變長度列表。

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二、記錄和集合的區別

???????? Records可以形象的理解為一個容器，用來保存很多其他的數據類型，但每種數據類型只在記錄中出現一次，例如一個記錄中保存了如下數據類型：

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PL/SQL Record：

這個記錄中保存了布爾型、日期型、字符型和BLOB型變量，且每個變量都只出現了一次，每個存放其他數據類型的空間稱為域（Field）

SQL> edit

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DECLARE

??? TYPE myrecord IS RECORD

??????? (id number(8),

??????????? name varchar2(20)default 'Wilson',

??????????? birthday DATE

??????? );?

???????

??????? person myrecord;

BEGIN??

??????? person.id :=12345;

??????? person.birthday :=SYSDATE;

???????

???????DBMS_OUTPUT.PUT_LINE('Name: '|| person.name);

END;???

/

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SQL> /

Name: Wilson

===============================

SQL> edit

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DECLARE

??? person employees%ROWTYPE；

BEGIN

??? SELECT * INTO person

??? FROM employees WHEREemployee_id = 100;

???

??? DBMS_OUTPUT.PUT_LINE('Name: '|| person.first_name);

END;

/

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SQL> @notes/s37.sql

Name: Steven

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PL/SQL procedure successfully completed.

===============================================

eg3.

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SQL> edit

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DECLARE

??? TYPE t_rec IS RECORD

??????? (v_sal number(8),

???????? v_minsal number(8)default 1000,

???????? v_hire_dateemployees.hire_date%TYPE,

???????? v_reclemployees%ROWTYPE);

??? v_myrec t_rec;

BEGIN

??? v_myrec.v_sal := v_myrec.v_minsal+ 500;

??? v_myrec.v_hire_date :=SYSDATE;

??? SELECT * INTO v_myrec.v_recl

??? FROM employees WHEREemployee_id = 100;

???DBMS_OUTPUT.PUT_LINE(v_myrec.v_recl.last_name || ' ' ||???? TO_CHAR(v_myrec.v_hire_date) || ' '||???? TO_CHAR(v_myrec.v_sal));

END;

/

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SQL> @notes/s38.sql

King 24-AUG-14 1500

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PL/SQL procedure successfully completed.

CREATE TABLE retired_emps (

??????? EMPNO NUMBER(4),

??????? ENAME VARCHAR2(25),

??????? JOB?? VARCHAR2(9),

??????? MGR?? NUMBER(4),

??????? HIREDATE DATE,

??????? LEAVEDATE DATE,

??????? SAL?? NUMBER(7,2),

??????? COMM? NUMBER(7,2),

??????? DEPTNO NUMBER(2)

??? );

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SQL> @notes/s39.sql

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Table created.

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SQL> select * from retired_emps where empno = 124;

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no rows selected

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SQL> edit

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DECLARE

??? v_employee_number NUMBER :=124;

??? v_emp_rec?? employees%ROWTYPE;

BEGIN

??? SELECT * INTO v_emp_rec FROMemployees

??? WHERE employee_id =v_employee_number;

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??? INSERT INTOretired_emps(empno, ename, job, mgr,

??????????????? hiredate,leavedate, sal, comm, deptno)

??? VALUES( v_emp_rec.employee_id,v_emp_rec.last_name,

??????????? v_emp_rec.job_id,v_emp_rec.manager_id,

??????????? v_emp_rec.hire_date,SYSDATE,

??????????? v_emp_rec.salary,v_emp_rec.commission_pct,

???????????v_emp_rec.department_id);

??? COMMIT;

END;

/

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SQL> @notes/s40.sql

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PL/SQL procedure successfully completed.

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SQL> select * from retired_emps where empno = 124;

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EMPNO ENAME???????? JOB????????????? MGR HIREDATE? LEAVEDATE? SAL?? ????COMM????DEPTNO

---------- ----------????? --------------- --------- ------------------- ---------????? ---------- ---------- ----------

?????? 124 Mourgos??? ?ST_MAN?????100?? ?16-NOV-07?24-AUG-14?5800??????????????????? 50

=========================INSERT============================

SQL> edit

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DECLARE

??? v_employee_number NUMBER := 127;

??? v_emp_rec retired_emps%ROWTYPE;

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BEGIN

??? SELECT employee_id, last_name, job_id,manager_id,

??? hire_date, hire_date, salary,commission_pct,

??? department_id INTO v_emp_rec

??? FROM employees

??? WHERE employee_id = v_employee_number;

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??? INSERT INTO retired_emps

??? VALUES v_emp_rec;

??????????????? -- 將查詢結果打包到v_emp_rec中

END;

/

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SELECT * FROMretired_emps;

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SQL>@notes/s41.sql

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PL/SQL proceduresuccessfully completed.

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???? EMPNO ENAME?????? JOB????????MGR ??HIREDATE? LEAVEDATE?SAL?????? COMM???? DEPTNO

----------------------------------- --------- ---------- --------- --------- -------------------- ----------

?????? 124 Mourgos??????? ST_MAN?100? ?16-NOV-07 ?24-AUG-14??5800??????? 50

?????? 127 Landry?????????? ST_CLERK? 120 ?14-JAN-07??14-JAN-07???? 3200???????50

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=========================UPDATE============================

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SQL> edit

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SET VERIFY OFF

DECLARE

??????? v_employee_number NUMBER:= 127;

??????? v_emp_recretired_emps%ROWTYPE;

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BEGIN

??????? SELECT *

??????? INTO v_emp_rec

??????? FROM retired_emps

??????? WHERE empno =v_employee_number;

??????? v_emp_rec.leavedate :=CURRENT_DATE;

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??????? UPDATE retired_emps SETROW = v_emp_rec

???? ???WHERE empno = v_employee_number;

END;

/

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SELECT * FROM retired_emps;

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SQL> @notes/s42.sql

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PL/SQL procedure successfully completed.

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???? EMPNO ENAME??? ?JOB????????????? MGR HIREDATE? LEAVEDATE?????SAL?????? COMM???? DEPTNO

???? ---------- --------------? ---------- --------- ---------- ------------------?? ?---------- ---------- ----------

?????? 124 Mourgos????? ST_MAN????? 100 16-NOV-07 24-AUG-14?????5800??????????????? ???????50

?????? 127 Landry??????? ST_CLERK????? 120 14-JAN-07 24-AUG-14????? 3200??????????????????? 50

SQL> edit

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DECLARE

??? myrec employees%ROWTYPE;

BEGIN

??? myrec := NULL;

END;

/

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SQL> @notes/s43.sql

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PL/SQL procedure successfully completed.

轉載于:https://blog.51cto.com/wuyelan/1550342

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