Parameterized cursor for varient Table name?

Question

Hi all,
I am using Oracle 9i and have a cursor defined as :-
Code:
CREATE PROCEDURE Proc_Abc
AS
CURSOR
My_Cursor (UserName VARCHAR) IS
SELECT Emp_Name, Salary FROM Employee_Table
WHERE User_Name = UserName;     
(Rest of the code)
This code is working perfectly, but if I try to provide the table name through the cursor variable, it gives an error
Below is the code that I am writing to pass table name through variable:-
Code:
CREATE PROCEDURE Proc_Abc
AS
CURSOR
My_Cursor (TableName VARCHAR, UserName VARCHAR) IS
SELECT Emp_Name, Salary FROM TableName
WHERE User_Name = UserName;     
(Rest of the code)
All the tables that I need to pass through cursor variables have the same fields and are all pre known to me, thats why "SELECT Emp_Name, Salary " is remaining common throughout.
Please suggest how can I make a cursor with variant tables?
Thanks in advance.

Answer 1

The following procedure compares between two tables and then it picking the column from all_tab_column table and finally execute the SELECT statement to compare the data between this two table. But, you can proceed your program taking help from this -
satyaki>ed
Wrote file afiedt.buf
  1  create or replace procedure compr_tab_dat(TAR_TAB IN VARCHAR2,
  2                                            TAR_UID IN VARCHAR2,
  3                                            SRC_TAB IN VARCHAR2,
  4                                            SRC_UID IN VARCHAR2)
  5  is
  6   cursor c1
  7   is
  8    select column_name
  9    from (
10           select column_name,column_id
11           from all_tab_columns
12           where table_name = SRC_TAB
13           and   owner = SRC_UID
14           intersect
15           select column_name,column_id
16           from all_tab_columns
17           where table_name = TAR_TAB
18           and   owner = TAR_UID
19         )
20     order by column_id;
21   cursor c_count
22   is
23     select count(column_name) as c_cnt
24     from (
25             select column_name
26             from all_tab_columns
27             where table_name = SRC_TAB
28             and   owner = SRC_UID
29             intersect
30             select column_name
31             from all_tab_columns
32             where table_name = TAR_TAB
33             and   owner = TAR_UID
34           );
35   rec1 c1%rowtype;
36   rec2 c1%rowtype;
37   rec3 c1%rowtype;
38   rec6 c_count%rowtype;
39   cnt  number(10);
40   cnt1  number(10);
41   str  varchar2(32000);
42   --str  clob;
43  BEGIN
44     cnt := 0;
45     cnt1 := 1;
46     dbms_output.enable(10000000);
47     for rec6 in c_count
48     loop
49      cnt := rec6.c_cnt;
50     end loop;
51     if cnt = 0 then
52        dbms_output.put_line('No matched columns found.... ');
53     else
54        dbms_output.put_line('UnMatched Datas Are-- ');
55           str:='declare '||
56          '  cursor c3 '||
57          '  is '||
58          '    select ';
59           open c1;
60           loop
61             fetch c1 into rec1;
62             exit when c1%notfound;
63             if cnt = cnt1 then
64                str:= str||rec1.column_name;
65             elsif cnt1<cnt then
66               str:= str||rec1.column_name||',';
67             end if;
68             cnt1 := cnt1 + 1;
69           end loop;
70           close c1;
71           str:=str||' from '||SRC_TAB||
72                ' minus '||
73                ' select ';
74           cnt1:=1;
75           open c1;
76           loop
77             fetch c1 into rec2;
78             exit when c1%notfound;
79             if cnt = cnt1 then
80                str:= str||rec2.column_name;
81             elsif cnt1<cnt then
82                str:= str||rec2.column_name||',';
83             end if;
84             cnt1 := cnt1 + 1;
85           end loop;
86           close c1;
87           str:=str||' from '||TAR_TAB||';'||
88                ' r3 c3%rowtype; '||
89                ' begin '||
90                '   for r3 in c3 '||
91                '   loop '||
92                '     dbms_output.put_line(';
93           cnt1:=1;
94           open c1;
95           loop
96             fetch c1 into rec3;
97             exit when c1%notfound;
98             if cnt = cnt1 then
99                str:= str||' r3.'||rec3.column_name;
100             elsif cnt1<cnt then
101                str:= str||' r3.'||rec3.column_name||
102                     '||'',''||';
103                cnt1 := cnt1 + 1;
104             end if;
105           end loop;
106           close c1;
107           str:=str||');'||
108                ' end loop;'||
109                ' exception '||
110                '   when others then '||
111                '     dbms_output.put_line(sqlerrm); '||
112                ' end; ';
113     end if;
114     execute immediate(str);
115     --dbms_output.put_line(str);
116  exception
117    when others then
118      dbms_output.put_line(sqlerrm);
119* END;
120  /
Procedure created.
satyaki>
satyaki>
satyaki>
satyaki>create table emp_t
  2     as
  3       select * from emp
  4       where rownum < 5;
Table created.
satyaki>
satyaki>
satyaki>desc emp;
Name                                      Null?    Type
EMPNO                                     NOT NULL NUMBER(4)
ENAME                                              VARCHAR2(10)
JOB                                                VARCHAR2(9)
MGR                                                NUMBER(4)
HIREDATE                                           DATE
SAL                                                NUMBER(7,2)
COMM                                               NUMBER(7,2)
DEPTNO                                             NUMBER(2)
satyaki>
satyaki>
satyaki>desc emp_t;
Name                                      Null?    Type
EMPNO                                              NUMBER(4)
ENAME                                              VARCHAR2(10)
JOB                                                VARCHAR2(9)
MGR                                                NUMBER(4)
HIREDATE                                           DATE
SAL                                                NUMBER(7,2)
COMM                                               NUMBER(7,2)
DEPTNO                                             NUMBER(2)
satyaki>set lin 1000
satyaki>
satyaki>select * from emp;
     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
      7369 SMITH      CLERK           7902 17-DEC-80        800                    20
      7499 ALLEN      SALESMAN        7698 20-FEB-81       1600        300         30
      7521 WARD       SALESMAN        7698 22-FEB-81       1250        500         30
      7566 JONES      MANAGER         7839 02-APR-81       2975                    20
      7654 MARTIN     SALESMAN        7698 28-SEP-81       1250       1400         30
      7698 BLAKE      MANAGER         7839 01-MAY-81       2850                    30
      7782 CLARK      MANAGER         7839 09-JUN-81       2450                    10
      7788 SCOTT      ANALYST         7566 19-APR-87       3000                    20
      7839 KING       PRESIDENT            17-NOV-81       5000                    10
      7844 TURNER     SALESMAN        7698 08-SEP-81       1500          0         30
      7876 ADAMS      CLERK           7788 23-MAY-87       1100                    20
     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
      7900 JAMES      CLERK           7698 03-DEC-81        950                    30
      7902 FORD       ANALYST         7566 03-DEC-81       3000                    20
      7934 MILLER     CLERK           7782 23-JAN-82       1300                    10
14 rows selected.
satyaki>
satyaki>
satyaki>select * from emp_t;
     EMPNO ENAME      JOB              MGR HIREDATE         SAL       COMM     DEPTNO
      7369 SMITH      CLERK           7902 17-DEC-80        800                    20
      7499 ALLEN      SALESMAN        7698 20-FEB-81       1600        300         30
      7521 WARD       SALESMAN        7698 22-FEB-81       1250        500         30
      7566 JONES      MANAGER         7839 02-APR-81       2975                    20
satyaki>
satyaki>
satyaki>set serveroutput on
satyaki>
satyaki>
satyaki>begin
  2   compr_tab_dat('EMP_T','SCOTT','EMP','SCOTT');
  3  end;
  4  /
No matched columns found....
ORA-06535: statement string in EXECUTE IMMEDIATE is NULL or 0 length
PL/SQL procedure successfully completed.
satyaki>
satyaki>
satyaki>sho user;
USER is "TRG2"
satyaki>
satyaki>
satyaki>
satyaki>
satyaki>begin
  2       compr_tab_dat('EMP_T','TRG2','EMP','TRG2');
  3     end;
  4      /
  5  .
satyaki>
satyaki>ed
Wrote file afiedt.buf
  1  begin
  2       compr_tab_dat('EMP_T','TRG2','EMP','TRG2');
  3* end;
satyaki>/
UnMatched Datas Are--
7654,MARTIN,SALESMAN,7698,28-SEP-81,1250,1400,30
7698,BLAKE,MANAGER,7839,01-MAY-81,2850,,30
7782,CLARK,MANAGER,7839,09-JUN-81,2450,,10
7788,SCOTT,ANALYST,7566,19-APR-87,3000,,20
7839,KING,PRESIDENT,,17-NOV-81,5000,,10
7844,TURNER,SALESMAN,7698,08-SEP-81,1500,0,30
7876,ADAMS,CLERK,7788,23-MAY-87,1100,,20
7900,JAMES,CLERK,7698,03-DEC-81,950,,30
7902,FORD,ANALYST,7566,03-DEC-81,3000,,20
7934,MILLER,CLERK,7782,23-JAN-82,1300,,10
PL/SQL procedure successfully completed.N.B.: May be Any other member can come with much shorter or better technique than this one. But, according to your requirement - i'm posting it. Hope this will help you, or atleast give you some idea.
Regards.
Satyaki De.