Using a comma-delimited string in Dynamic SQL

Question

Hi --
If I receive a comma-delimited string as an in parameter, can I simply use that (in string format) when building my dynamic sql?
Thanks,
Christine

Answer 1

The problem is, that you can not use bind variables
here, only literals. This causes
eventual performance problems.And to avoid the inevitable database performance problems Dmytro mentions you can use a function to convert the string to a varray and select from that. This also avoids having to use dynamic sql.
First you create a varray and conversion function.
SQL> create or replace type tabstr_t as table of varchar2(255)
  2  /
Type created.
SQL> create or replace function tabstr (
  2      p_str in varchar2,
  3      p_sep in varchar2 default ','
  4      )
  5  return tabstr_t
  6  as
  7      l_str long default p_str || p_sep;
  8      l_tabstr tabstr_t := tabstr_t();
  9  begin
10      while l_str is not null loop
11          l_tabstr.extend(1);
12          l_tabstr(l_tabstr.count) := rtrim(substr(
13                  l_str,1,instr(l_str,p_sep)),p_sep);
14          l_str := substr(l_str,instr(l_str,p_sep)+1);
15      end loop;
16      return l_tabstr;
17  end;
18  /
Function created.Then you can use these in either regular sql.
SQL> var s varchar2(100)
SQL> exec :s := 'Smith,Scott,Miller'
PL/SQL procedure successfully completed.
SQL>
SQL> select * from emp where ename in
  2      (select upper(column_value) from table(tabstr(:s)));
EMPNO ENAME    JOB          MGR HIREDATE     SAL   COMM  DEPTNO
  7369 SMITH    CLERK       7902 17-DEC-80    800             20
  7788 SCOTT    ANALYST     7566 09-DEC-82   3000             20
  7934 MILLER   CLERK       7782 23-JAN-82   1300             10Or in pl/sql.
SQL> var c refcursor
SQL> begin
  2      open :c for
  3      select * from emp where ename in
  4          (select upper(column_value) from table(tabstr(:s)));
  5  end;
  6  /
PL/SQL procedure successfully completed.
SQL> print c
EMPNO ENAME    JOB          MGR HIREDATE     SAL   COMM  DEPTNO
  7369 SMITH    CLERK       7902 17-DEC-80    800             20
  7788 SCOTT    ANALYST     7566 09-DEC-82   3000             20
  7934 MILLER   CLERK       7782 23-JAN-82   1300             10