Oracle PL/SQL/Cursor/Cursor Open — различия между версиями
Admin (обсуждение | вклад) м (1 версия) |
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Версия 13:45, 26 мая 2010
Содержание
An illegal location for a cursor.
SQL>
SQL> CREATE TABLE lecturer (
2 id NUMBER(5) PRIMARY KEY,
3 first_name VARCHAR2(20),
4 last_name VARCHAR2(20),
5 major VARCHAR2(30),
6 current_credits NUMBER(3)
7 );
Table created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10001, "Scott", "Lawson","Computer Science", 11);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major, current_credits)
2 VALUES (10002, "Mar", "Wells","History", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10003, "Jone", "Bliss","Computer Science", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10004, "Man", "Kyte","Economics", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10005, "Pat", "Poll","History", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10006, "Tim", "Viper","History", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10007, "Barbara", "Blues","Economics", 7);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10008, "David", "Large","Music", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10009, "Chris", "Elegant","Nutrition", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10010, "Rose", "Bond","Music", 7);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10011, "Rita", "Johnson","Nutrition", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10012, "Sharon", "Clear","Computer Science", 3);
1 row created.
SQL>
SQL>
SQL> DECLARE
2 FUNCTION FormatName(p_FirstName IN VARCHAR2,
3 p_LastName IN VARCHAR2)
4 RETURN VARCHAR2 IS
5 BEGIN
6 RETURN p_FirstName || " " || p_LastName;
7 END FormatName;
8
9 CURSOR myAllLecturer IS
10 SELECT first_name, last_name
11 FROM lecturer;
12
13 v_FormattedName VARCHAR2(50);
14
15 BEGIN
16 NULL;
17 END;
18 /
CURSOR myAllLecturer IS
*
ERROR at line 9:
ORA-06550: line 9, column 3:
PLS-00103: Encountered the symbol "CURSOR" when expecting one of the following:
begin function package pragma procedure form
SQL>
SQL> drop table lecturer;
Table dropped.
SQL>
Cursor OPEN Example
SQL>
SQL>
SQL>
SQL> CREATE TABLE place (
2 room_id NUMBER(5) PRIMARY KEY,
3 building VARCHAR2(15),
4 room_number NUMBER(4),
5 number_seats NUMBER(4),
6 description VARCHAR2(50)
7 );
Table created.
SQL>
SQL> INSERT INTO place (room_id, building, room_number, number_seats, description)
2 VALUES (20001, "Building 7", 201, 1000, "Large Lecture Hall");
1 row created.
SQL>
SQL> INSERT INTO place (room_id, building, room_number, number_seats, description)
2 VALUES (20002, "Building 6", 101, 500, "Small Lecture Hall");
1 row created.
SQL>
SQL> INSERT INTO place (room_id, building, room_number, number_seats, description)
2 VALUES (20003, "Building 6", 150, 50, "Discussion Room A");
1 row created.
SQL>
SQL> INSERT INTO place (room_id, building, room_number, number_seats, description)
2 VALUES (20004, "Building 6", 160, 50, "Discussion Room B");
1 row created.
SQL>
SQL> INSERT INTO place (room_id, building, room_number, number_seats,description)
2 VALUES (20005, "Building 6", 170, 50, "Discussion Room C");
1 row created.
SQL>
SQL> INSERT INTO place (room_id, building, room_number, number_seats, description)
2 VALUES (20006, "Music Building", 100, 10, "Music Practice Room");
1 row created.
SQL>
SQL> INSERT INTO place (room_id, building, room_number, number_seats, description)
2 VALUES (20007, "Music Building", 200, 1000, "Concert Room");
1 row created.
SQL>
SQL> INSERT INTO place (room_id, building, room_number, number_seats, description)
2 VALUES (20008, "Building 7", 300, 75, "Discussion Room D");
1 row created.
SQL>
SQL> INSERT INTO place (room_id, building, room_number, number_seats,description)
2 VALUES (20009, "Building 7", 310, 50, "Discussion Room E");
1 row created.
SQL>
SQL>
SQL> CREATE TABLE session (
2 department CHAR(3),
3 course NUMBER(3),
4 description VARCHAR2(2000),
5 max_lecturer NUMBER(3),
6 current_lecturer NUMBER(3),
7 num_credits NUMBER(1),
8 room_id NUMBER(5)
9 );
Table created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("HIS", 101, "History 101", 30, 11, 4, 20000);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("HIS", 301, "History 301", 30, 0, 4, 20004);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("CS", 101, "Computer Science 101", 50, 0, 4, 20001);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("ECN", 203, "Economics 203", 15, 0, 3, 20002);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("CS", 102, "Computer Science 102", 35, 3, 4, 20003);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("MUS", 410, "Music 410", 5, 4, 3, 20005);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("ECN", 101, "Economics 101", 50, 0, 4, 20007);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("NUT", 307, "Nutrition 307", 20, 2, 4, 20008);
1 row created.
SQL>
SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("MUS", 100, "Music 100", 100, 0, 3, NULL);
1 row created.
SQL>
SQL>
SQL> DECLARE
2 v_RoomID session.room_id%TYPE;
3 v_Building place.building%TYPE;
4 v_Department session.department%TYPE;
5 v_Course session.course%TYPE;
6 CURSOR c_Buildings IS
7 SELECT building
8 from place, session
9 where place.room_id = session.room_id
10 and department = v_Department
11 and course = v_Course;
12 BEGIN
13 v_Department := "HIS";
14 v_Course := 101;
15
16 OPEN c_Buildings;
17
18 v_Department := "XXX";
19 v_Course := -1;
20 END;
21 /
PL/SQL procedure successfully completed.
SQL>
SQL> drop table session;
Table dropped.
SQL> drop table place;
Table dropped.
SQL>
SQL>
Open a cursor based on the result of row_number over partition by, order by
SQL>
SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
2 ENAME VARCHAR2(10),
3 JOB VARCHAR2(9),
4 MGR NUMBER(4),
5 HIREDATE DATE,
6 SAL NUMBER(7, 2),
7 COMM NUMBER(7, 2),
8 DEPTNO NUMBER(2));
Table created.
SQL>
SQL> INSERT INTO EMP VALUES (7369, "SMITH", "CLERK", 7902, TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7499, "ALLEN", "SALESMAN", 7698, TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7521, "WARD", "SALESMAN", 7698, TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7566, "JONES", "MANAGER", 7839, TO_DATE("2-APR-1981", "DD-MON-YYYY"), 2975, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10);
1 row created.
SQL>
SQL> select * from emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
-------- ---------- --------- -------- --------- -------- -------- ------
7369.00 SMITH CLERK 7902.00 17-DEC-80 800.00 20
7499.00 ALLEN SALESMAN 7698.00 20-FEB-81 1600.00 300.00 30
7521.00 WARD SALESMAN 7698.00 22-FEB-81 1250.00 500.00
7566.00 JONES MANAGER 7839.00 02-APR-81 2975.00 20
7654.00 MARTIN SALESMAN 7698.00 28-SEP-81 1250.00 1400.00 30
7698.00 BLAKE MANAGER 7839.00 01-MAY-81 2850.00
7782.00 CLARK MANAGER 7839.00 09-JUN-81 2450.00 10
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
-------- ---------- --------- -------- --------- -------- -------- ------
7788.00 SCOTT ANALYST 7566.00 09-DEC-82 3000.00 20
7839.00 KING PRESIDENT 17-NOV-81 5000.00 10
7844.00 TURNER SALESMAN 7698.00 08-SEP-81 1500.00 .00 30
7876.00 ADAMS CLERK 7788.00 12-JAN-83 1100.00 20
7900.00 JAMES CLERK 7698.00 03-DEC-81 950.00 30
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
-------- ---------- --------- -------- --------- -------- -------- ------
7902.00 FORD ANALYST 7566.00 03-DEC-81 3000.00 20
7934.00 MILLER CLERK 7782.00 23-JAN-82 1300.00 10
14 rows selected.
SQL> begin
2 open :x for
3 "select mgr,
4 ename,
5 row_number() over ( partition by mgr
6 order by ename ) rn
7 from emp";
8 end;
9 /
PL/SQL procedure successfully completed.
MGR ENAME RN
-------- ---------- --------
7566.00 FORD 1.00
7566.00 SCOTT 2.00
7698.00 ALLEN 1.00
7698.00 JAMES 2.00
7698.00 MARTIN 3.00
7698.00 TURNER 4.00
7698.00 WARD 5.00
7782.00 MILLER 1.00
7788.00 ADAMS 1.00
7839.00 BLAKE 1.00
7839.00 CLARK 2.00
MGR ENAME RN
-------- ---------- --------
7839.00 JONES 3.00
7902.00 SMITH 1.00
KING 1.00
14 rows selected.
SQL>
SQL> drop table emp;
Table dropped.
Open a cursor for read
SQL>
SQL> -- create demo table
SQL> create table Employee(
2 ID VARCHAR2(4 BYTE) NOT NULL,
3 First_Name VARCHAR2(10 BYTE),
4 Last_Name VARCHAR2(10 BYTE),
5 Start_Date DATE,
6 End_Date DATE,
7 Salary Number(8,2),
8 City VARCHAR2(10 BYTE),
9 Description VARCHAR2(15 BYTE)
10 )
11 /
Table created.
SQL>
SQL> -- prepare data
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values ("01","Jason", "Martin", to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto", "Programmer")
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("02","Alison", "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("03","James", "Smith", to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("04","Celia", "Rice", to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("05","Robert", "Black", to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("06","Linda", "Green", to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York", "Tester")
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("07","David", "Larry", to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York", "Manager")
3 /
1 row created.
SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("08","James", "Cat", to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
3 /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
2 /
ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION
---- ---------- ---------- --------- --------- ---------- ---------- ---------------
01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer
02 Alison Mathews 21-MAR-76 21-FEB-86 6661.78 Vancouver Tester
03 James Smith 12-DEC-78 15-MAR-90 6544.78 Vancouver Tester
04 Celia Rice 24-OCT-82 21-APR-99 2344.78 Vancouver Manager
05 Robert Black 15-JAN-84 08-AUG-98 2334.78 Vancouver Tester
06 Linda Green 30-JUL-87 04-JAN-96 4322.78 New York Tester
07 David Larry 31-DEC-90 12-FEB-98 7897.78 New York Manager
08 James Cat 17-SEP-96 15-APR-02 1232.78 Vancouver Tester
8 rows selected.
SQL>
SQL>
SQL>
SQL> declare
2 cursor employeeCursor
3 is select e.first_name || " " || e.last_name name, e.salary
4 from employee e;
5
6 name varchar2(200);
7 salary number(9,2);
8 begin
9 for c1 in (select avg(e.salary) avg_salary
10 from employee e) loop
11 dbms_output.put_line("average salary "||c1.avg_salary);
12 end loop;
13
14 open employeeCursor;
15 fetch employeeCursor into name, salary;
16
17 dbms_output.put_line(chr(13) || chr(13));
18 dbms_output.put_line("EmployeeS");
19 dbms_output.put_line("------------------------");
20
21 while employeeCursor%FOUND loop
22 dbms_output.put_line(name || " makes $" || salary);
23 fetch employeeCursor into name, salary;
24 end loop;
25 close employeeCursor;
26 end;
27 /
average salary 4071.7525
EmployeeS
------------------------
Jason Martin makes $1234.56
Alison Mathews makes $6661.78
James Smith makes $6544.78
Celia Rice makes $2344.78
Robert Black makes $2334.78
Linda Green makes $4322.78
David Larry makes $7897.78
James Cat makes $1232.78
PL/SQL procedure successfully completed.
SQL>
SQL>
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
2 /
Table dropped.
SQL>
SQL>
SQL>
SQL>
Open cursor from a dynamic statement
SQL>
SQL> CREATE TABLE MyTable(yourRow INTEGER, yourDesc VARCHAR2(50));
Table created.
SQL>
SQL> SET ECHO ON
SQL> SET SERVEROUTPUT ON
SQL>
SQL> DECLARE
2 TYPE your_cursor_type IS REF CURSOR;
3 your_cursor your_cursor_type;
4
5 TYPE dyn_record IS RECORD (
6 yourrow INTEGER,
7 yourdesc VARCHAR2(50)
8 );
9
10 dyn_rec dyn_record;
11
12 dynamic_select_stmt VARCHAR2(100);
13 BEGIN
14 dynamic_select_stmt := "SELECT yourrow, yourdesc FROM mytable";
15 dynamic_select_stmt := dynamic_select_stmt || " ORDER BY yourrow DESC";
16
17 OPEN your_cursor FOR dynamic_select_stmt;
18
19 LOOP
20 FETCH your_cursor
21 INTO dyn_rec;
22 EXIT WHEN your_cursor%NOTFOUND;
23
24 DBMS_OUTPUT.PUT_LINE(dyn_rec.yourrow || " " || dyn_rec.yourdesc);
25 END LOOP;
26 CLOSE your_cursor;
27 END;
28 /
PL/SQL procedure successfully completed.
SQL>
SQL> drop table mytable;
Table dropped.
SQL>
SQL> --
ORA-6511 error: cursor already open
SQL>
SQL>
SQL> CREATE TABLE lecturer (
2 id NUMBER(5) PRIMARY KEY,
3 first_name VARCHAR2(20),
4 last_name VARCHAR2(20),
5 major VARCHAR2(30),
6 current_credits NUMBER(3)
7 );
Table created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10001, "Scott", "Lawson","Computer Science", 11);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major, current_credits)
2 VALUES (10002, "Mar", "Wells","History", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10003, "Jone", "Bliss","Computer Science", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10004, "Man", "Kyte","Economics", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10005, "Pat", "Poll","History", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10006, "Tim", "Viper","History", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10007, "Barbara", "Blues","Economics", 7);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10008, "David", "Large","Music", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10009, "Chris", "Elegant","Nutrition", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10010, "Rose", "Bond","Music", 7);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10011, "Rita", "Johnson","Nutrition", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10012, "Sharon", "Clear","Computer Science", 3);
1 row created.
SQL>
SQL>
SQL> DECLARE
2 myLecturerID lecturer.ID%TYPE;
3
4 CURSOR c_AllStudentIDs IS
5 SELECT ID FROM lecturer;
6 BEGIN
7 OPEN c_AllStudentIDs;
8
9 OPEN c_AllStudentIDs;
10 END;
11 /
DECLARE
*
ERROR at line 1:
ORA-06511: PL/SQL: cursor already open
ORA-06512: at line 5
ORA-06512: at line 9
SQL>
SQL>
SQL> drop table lecturer;
Table dropped.
SQL>
SQL>