Ref cursor vs dbms_sql

Hello

What is the difference between dbms_sql and ref cursor.

Thank you

Smidreb wrote:

What is the difference between dbms_sql and ref cursor.

Client language interfaces of SQL cursors.

All SQL are analyzed, stored and runs as sliders (including anonymous PL/SQL blocks). All cursors are equal. In other words, there is no such thing as a ref cursor or implicit cursor or cursor DBMS_SQL in the SQL engine. There are only cursors and they work all the same. There is a standard Oracle Call Interface to create and use and throw sliders.

On the side of the customer's language (PL/SQL, Java, C/C++, etc.), there are usually a number of interfaces of client language by using the Oracle Call Interface for dealing with the sliders.

In Delphi for example, there are different classes for different types of sliders (dynamic SQL statements, static SQL on a table, PL/SQL calls, etc.). In PL/SQL, there are also various interfaces in the language for using cursors.

REF CURSOR is such an interface - with a specific feature to create and analyze the cursor using PL/SQL and then switch this slider handle to an external client language so he could use it.

DBMS_SQL is a simplistic implementation of the actual Oracle Call Interface for cursors. Lower level stuff - this is basically how it works under the hood when dealing with a slider. Features are dynamic, binding and dealing with dynamically projection SQL cursors. This is widely used by applications such as Apex which deals really dynamic SQL and all aspects of it.

Tags: Database

Similar Questions

Ref Cursor on implicit and explicit cursors
Hello

In my company the drafting of PL/SQL procedure, everyone uses "Ref Cursor",
But the article below, said implicit is the best, then Explicit and Ref Cursor...

[http://www.oracle-base.com/forums/viewtopic.php?f=2 & t = 10720]

I'm a bit confused by this, can someone help me understand this?

Thank you
SeshuGiri wrote:

In my company the drafting of PL/SQL procedure, everyone uses "Ref Cursor",
But the article below, said implicit is the best, then Explicit and Ref Cursor...

[http://www.oracle-base.com/forums/viewtopic.php?f=2&t=10720]

I'm a bit confused by this, can someone help me understand this?

It has performance and it has performance...

To explain. There is one type of cursor in Oracle - that is the cursor which is analyzed and compiled by the SQL engine and stored in the shared the database pool. The "+ client +" then receives a handle (called a SQL statement handle of many APIs) that can be used to make reference to this slider in the SQL engine.

The performance of this slider is not determined by the customer. It is determined by the execution plan and how much enforcement of this slider cost ito of server resources.

The customer can be Java, VB, .net - or a PL/SQL program. This client language (SQL client), has its own structures dealing with this from the SQL engine cursor handle.

It can hide by the developer all together - so that they can't even see that there is a statement handle. That's what the implicit cursors in PL/SQL.

It can allow the developer to manually define the structure of slider - this is what the explicit cursors, ref Cursor and DBMS_SQL cursors in PL/SQL.

Each of these client cursor structures provides the programmer with a set of features to address different SQL cursor. Explicit cursor in PL/SQL constructs do not have the use of dynamic SQL statements. REF CURSOR and cursors DBMS_SQL do. REF CURSOR does not allow the programmer determine, at runtime, the structure of the projection of the cursor SQL. DBMS_SQL sliders do.

Only ref Cursor can be created in PL/SQL and then handed over to another client (for example, Java/VB) for treatment. Etc.

If each of the works of art/customer interfaces gives you a different feature for SQL cursors.

Choose the implicit cursors for example does not the SQL cursor move faster. The SQL engine does not know and does not care, which customer construct you use to deal with the SQL cursor handle, he gave you. It does not matter. It does not affect his performance of cursor SQL.

But on the client side, it can matter - if your code when dealing with that SQL cursor determines how fast your interaction with this SQL cursor is. How many context changes you make. How you use and reuse the SQL (for example hard vs soft analysis vs analysis reusing the same cursor handle). Etc.

Are there any unique client cursor construction which is better? N °

It's ignorant views. The customer's language provides a box tool, where each tool has a specific application. The competent developer will use the right tool for the job. The stupid developer will select a tool and use it as The Hammer to 'solve' all problems.

Report regions - use of the Ref Cursor?

APEX 4.2
See http://mikesmithers.wordpress.com/2012/02/22/getting-apex-to-play-with-ref-cursors
The above article is older than 2 years. The techniques shown in the link above still valid today if we want to create a report region in the APEX are based on a function that returns a Ref Cursor? Are there improvements in this area for the next APEX 5.0 and/or database Oracle 12 c?
Thank you

HELEN wrote:

APEX 4.2

See http://mikesmithers.wordpress.com/2012/02/22/getting-apex-to-play-with-ref-cursors

The above article is older than 2 years. The techniques shown in the link above still valid today if we want to create a report region in the APEX are based on a function that returns a Ref Cursor?

If the function returns the ref cursor is the only point of access that you have data then Yes, it probably is. If you have direct access to the underlying database objects and the function does not have something very complicated, then you are probably better off creating your own body of the function returning SQL query data source.

Everything about the dynamics of ref Cursor now I divided in 2 layers, with a function for generating the dynamic SQL and another for bind parameters open the ref cursor. APEX apps can then reuse the functions of SQL query in function body return SQL query data sources (if you take a bit of care to keep the bind variable names vaguely APEX-point-friendly).

Are there improvements in this area for the next APEX 5.0 and/or database Oracle 12 c?

See this for the technical background on why APEX is not yet support ref Cursor and this for more information of the Oracle team on the possibility of future support. Obviously, he did not he in 4.1. I suspect that data REF CURSOR region sources depended on a minimum requirement of DB of the 11.1.0.6 (where was introduced support for the conversion of the REF CURSOR in the cursors DBMS_SQL). As minimum DB for APEX 5.0 version is 11.1.0.7, it would be a possible feature for 5.0, but it is not classified as one.

sys_refcursor and Ref Cursor
Hello

I found this diffrence between ref and sys_refcursor slider.

If you specify return_type, then the variables of type and slider REF CURSOR of this type are strong; If not,
they are weak.
The variables SYS_REFCURSOR and slider of this type are weak.

my situation is that I must write a procedure stored so many reports entery pages. little enter pages use typed data groups and can't.

so please tel me what is the best in terms of performance and maintainability above three conditions?

Yours sincerely
944768 wrote:

my situation is that I must write a procedure stored so many reports entery pages. little enter pages use typed data groups and can't.

Called stored procedures what and where?

If, with a layer of app such as Java or .net, then they do not distinguish between weak and strong ref Cursor - because it is a concept of PL/SQL.

And by using a ref cursor type in PL/SQL is intended to provide a mechanism to pass the handle of real cursor SQL cursor created in this session, the client (for example Java or .net). Nothing more. So, why even care that PL/SQL? a weak or strong Ref to the application layer slider

so please tel me what is the best in terms of performance and maintainability above three conditions?

I find always frustrating that there is this concept that some methods to create cursors, results in faster and better than other methods, the sliders. It is a concept of bs. All SQLs are analyzed as a SQL cursors. Each. Unique. One. By the SAME CBO.

If the client code (Java, PL/SQL or other) you write for this SQL cursor DOES NOT change the source SQL.

This therefore does not cause the CBO now compile a different SQL execution plan for her. The CBO does not care if your code uses a strong Ref Cursor or a weak Ref Cursor, or a slider DBMS_SQL, an explicit cursor, or whatever. Those are concepts of customer. And do not change the execution plan of cursor SQL on the server. Or its planned performance/cost.

Yes, your client code (Java, PL/SQL, etc.) can use the SQL cursor on the server-side evil - and this can affect performance.

But waiting for a weak Ref cursor will somehow cause a faster cursor or slower for the same SQL statement, that a strong Ref cursor is not understanding what SQL cursor is, and how the customer interacts with its data types, the classes of customers and its customer interfaces with this SQL cursor.

The use of bind variables in dynamic query created for Ref Cursor

Hello

I'm in a situation where there is a Ref cursor to which the query is built execution based on a loop. This is why the number of links would be known until the program runs.
The application is currently using literals instead of bind variables.

code snippet of the above is
strSql: = "select * from emp where 1 = 1 and ().

loop cursor1
If cond is true then
strSql = strSql | "ename = ' |" Cursor1.ColumnName;
end loop;

Open cursor2 for strSql;

How to use links in the example above.

sb92075 wrote:

user13019948 wrote:
Hello

Here is the code I have my trying to change literal-based link to the base.

What do you mean by "based bind?

who, what, how determines the values to be 'bound '?

He's referring to the coding style. He is currently using concatenated literal, and the goal is to change it to use the bindings.

If I understand this it is known as method 4 dynamic SQL and requires DBMS_SQL. There are examples autour but they vary according to the type of statement being generated - SELECT statements require column lists to be parsed, unlike the INSERT/UPDATE/DELETE.

This came up recently on my current project and I hit a demo. Here a table of names and values accepted procedure and had to build these in a single WHERE clause along the lines of

AND t_names(i) = t_values(i)

for an undetermined number of elements in the array. For this demonstration, I used a table that we called "attribute" (don't ask) which has columns including 'attribute_id' and 'name', and I need to build a query along the lines of

select description from attribute where attribute_id = :b1 and name = :b2

by the way '1012' and 'ISIN' respectively. (I use a table better and after a CREATE statement for her but I have to rush right now, sorry).

declare
   k_sql_base        constant varchar2(500) := 'select description from attribute';

   t_names           constant varchar2_t := varchar2_t('attribute_id',  'name');
   t_values          constant varchar2_t := varchar2_t('1012',          'ISIN');

   l_sql             varchar2(500) := k_sql_base;
   l_rows_fetched    integer := 0;
   l_value           varchar2(4000);

   l_cursor_handle   integer;

begin
   -- Construct the SQL statement with column names and bind variables e.g.
   -- 'select description from mars.attribute where attribute_id = :b1 and name = :b2'
   for i in t_names.first .. t_names.last loop
      l_sql := l_sql ||
         case i
            when t_names.first then ' where ' else ' and '
         end ||
         t_names(i) || ' = :b' || i;
   end loop;

   dbms_output.put_line('SQL statment = ' || l_sql); 

   -- Parse the statement we built above (the remaining steps require a parsed cursor):
   l_cursor_handle := dbms_sql.open_cursor;
   dbms_sql.parse(l_cursor_handle, l_sql, dbms_sql.native);

   -- Associate the 1st column of output with variable l_value - required for SELECT statements:
   -- (actually the 3rd param here 'column' seems to be only used to get a datatype, in this case we want a string -
   -- dbms_sql.column_value actually extracts the value into a specified variable, which can be different.
   -- All examples in the documentation pass a local variable without further comment, so not entirely clear what this does other than set the output datatype.)
   dbms_sql.define_column(l_cursor_handle, 1, l_value, 4000);

   -- Now go through values array binding actual values to :bn variables in the cursor (similar to USING clause of EXECUTE IMMEDIATE)
   for i in t_values.first .. t_values.last loop
      dbms_sql.bind_variable(l_cursor_handle, ':b'||i, t_values(i));
      dbms_output.put_line('Bound :b'||i || ' as ' || t_values(i));
   end loop;

   -- Open the cursor and fetch the result (no loop here because we are expecting a single-row result):
   l_rows_fetched := dbms_sql.execute_and_fetch(l_cursor_handle);

   -- 'Returns value of the cursor element for a given position in a cursor'
   -- Copy the value of column 1 to variable l_value (has to match
   -- dbms_sql.column_value(l_cursor_handle, 1, l_value);
   dbms_sql.column_value(l_cursor_handle, 1, l_value);

   dbms_output.put_line('Result = ''' || l_value || '''');

   dbms_sql.close_cursor(l_cursor_handle);
end;

Hope that helps...

Retrieve the Ref cursor data
Hello

Here is the plsql code, I try to extract the data from the refcursor

Declare
number of l_ecg_id_in;
number of l_error_code_out;
l_cur_out sys_refcursor;
Begin

l_ecg_id_in: = 1249551;

-Call the procedure
pkg_dispatch.sp_getecgreport (p_ecg_id_in = > l_ecg_id_in,)
p_cur_out = > l_cur_out, / / p_cur_out is back refcursor datat
p_error_code_out = > l_error_code_out);

Now my requirement is data retrieves in l_cur_out have too many columns, the columns are mentioned below.
HUMAN RESOURCES
PR
DR
BATTERY
ETC.

I want to just HR to be extacted in a variable or a collection of type

We can extract a particular of ref cursor column, please suggest me

End;
Sudhir_Bangalore wrote:

Now my requirement is data retrieves in l_cur_out have too many columns, the columns are mentioned below.
HUMAN RESOURCES
PR
DR
BATTERY
ETC.

I want to just HR to be extacted in a variable or a collection of type

Then, you use the wrong cursor and you performance degradation because the cursor returns data that is not required.

We can extract a particular of ref cursor column, please suggest me

You can not.

Workaround would be to copy the handle of the cursor ref to a handle to the cursor DBMS_SQL and then use cursor DBMS_SQL to treat the projection of SQL. But it would be an ugly hack.

The right approach would be to correctly use the SQL cursors in PL/SQL. And no, ref Cursor in PL/SQL (created by code PL/SQL to PL/SQL code) is almost always the WRONG choice.

There are better native cursor data types in PL/SQL in particular supported cursors created by PL/SQL and PL/SQL.

REF CURSOR is provided mainly as the cursors created by PL/SQL for an external client. There are very few reasons to create Ref cursors to use PL/SQL code.

Converts the ref cursor effect of function table

I have a function named fn_get_emp(), whose return type is sys_refcursor. When I select fn_get_emp of double; I get the output to the format of the cursor. I want to convert to the table like format so that I can use in my insert statements insert into foo select * from fn_get_emp();

Please note that the columns in the output of the fn_get_emp() is not fixed.

Published by: user10566312 on January 30, 2012 22:25

Here are the steps in the package DBMS_SQL, you need to turn your Ref Cursor a cursor DBMS_SQL.

http://docs.Oracle.com/CD/E11882_01/AppDev.112/e25788/d_sql.htm#CHDJDGDG

and then the rest of the documentation of the DBMS_SQL package gives many examples of how to treat this a cursor dbms_sql.

Here is an example to use the package dbms_sql to process a request and produce some projection of sql and the database is in the query to CSV file...

As user sys:

CREATE OR REPLACE DIRECTORY TEST_DIR AS '\tmp\myfiles'
/
GRANT READ, WRITE ON DIRECTORY TEST_DIR TO myuser
/

As myuser:

CREATE OR REPLACE PROCEDURE run_query(p_sql IN VARCHAR2
                                     ,p_dir IN VARCHAR2
                                     ,p_header_file IN VARCHAR2
                                     ,p_data_file IN VARCHAR2 := NULL) IS
  v_finaltxt  VARCHAR2(4000);
  v_v_val     VARCHAR2(4000);
  v_n_val     NUMBER;
  v_d_val     DATE;
  v_ret       NUMBER;
  c           NUMBER;
  d           NUMBER;
  col_cnt     INTEGER;
  f           BOOLEAN;
  rec_tab     DBMS_SQL.DESC_TAB;
  col_num     NUMBER;
  v_fh        UTL_FILE.FILE_TYPE;
  v_samefile  BOOLEAN := (NVL(p_data_file,p_header_file) = p_header_file);
BEGIN
  c := DBMS_SQL.OPEN_CURSOR;
  DBMS_SQL.PARSE(c, p_sql, DBMS_SQL.NATIVE);
  d := DBMS_SQL.EXECUTE(c);
  DBMS_SQL.DESCRIBE_COLUMNS(c, col_cnt, rec_tab);
  FOR j in 1..col_cnt
  LOOP
    CASE rec_tab(j).col_type
      WHEN 1 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
      WHEN 2 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_n_val);
      WHEN 12 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_d_val);
    ELSE
      DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
    END CASE;
  END LOOP;
  -- This part outputs the HEADER
  v_fh := UTL_FILE.FOPEN(upper(p_dir),p_header_file,'w',32767);
  FOR j in 1..col_cnt
  LOOP
    v_finaltxt := ltrim(v_finaltxt||','||lower(rec_tab(j).col_name),',');
  END LOOP;
  --  DBMS_OUTPUT.PUT_LINE(v_finaltxt);
  UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
  IF NOT v_samefile THEN
    UTL_FILE.FCLOSE(v_fh);
  END IF;
  --
  -- This part outputs the DATA
  IF NOT v_samefile THEN
    v_fh := UTL_FILE.FOPEN(upper(p_dir),p_data_file,'w',32767);
  END IF;
  LOOP
    v_ret := DBMS_SQL.FETCH_ROWS(c);
    EXIT WHEN v_ret = 0;
    v_finaltxt := NULL;
    FOR j in 1..col_cnt
    LOOP
      CASE rec_tab(j).col_type
        WHEN 1 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_v_val);
                    v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
        WHEN 2 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_n_val);
                    v_finaltxt := ltrim(v_finaltxt||','||v_n_val,',');
        WHEN 12 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_d_val);
                    v_finaltxt := ltrim(v_finaltxt||','||to_char(v_d_val,'DD/MM/YYYY HH24:MI:SS'),',');
      ELSE
        v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
      END CASE;
    END LOOP;
  --  DBMS_OUTPUT.PUT_LINE(v_finaltxt);
    UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
  END LOOP;
  UTL_FILE.FCLOSE(v_fh);
  DBMS_SQL.CLOSE_CURSOR(c);
END;

This allows the header line and the data to write into files separate if necessary.

for example

SQL> exec run_query('select * from emp','TEST_DIR','output.txt');

PL/SQL procedure successfully completed.

Output.txt file contains:

empno,ename,job,mgr,hiredate,sal,comm,deptno
7369,"SMITH","CLERK",7902,17/12/1980 00:00:00,800,,20
7499,"ALLEN","SALESMAN",7698,20/02/1981 00:00:00,1600,300,30
7521,"WARD","SALESMAN",7698,22/02/1981 00:00:00,1250,500,30
7566,"JONES","MANAGER",7839,02/04/1981 00:00:00,2975,,20
7654,"MARTIN","SALESMAN",7698,28/09/1981 00:00:00,1250,1400,30
7698,"BLAKE","MANAGER",7839,01/05/1981 00:00:00,2850,,30
7782,"CLARK","MANAGER",7839,09/06/1981 00:00:00,2450,,10
7788,"SCOTT","ANALYST",7566,19/04/1987 00:00:00,3000,,20
7839,"KING","PRESIDENT",,17/11/1981 00:00:00,5000,,10
7844,"TURNER","SALESMAN",7698,08/09/1981 00:00:00,1500,0,30
7876,"ADAMS","CLERK",7788,23/05/1987 00:00:00,1100,,20
7900,"JAMES","CLERK",7698,03/12/1981 00:00:00,950,,30
7902,"FORD","ANALYST",7566,03/12/1981 00:00:00,3000,,20
7934,"MILLER","CLERK",7782,23/01/1982 00:00:00,1300,,10

The procedure allows for the header and the data to separate files if necessary. Just by specifying the file name "header" will put the header and the data in a single file.

Adapt to the exit of styles and different types of data are needed.

Ref cursor - result series is not known

Hi all

My requirement is as below
(1) the query to run is stored in a table because the query vary each time
(2) execution of the query and treat it

As the query could be of any table that I'm stuck on go get the query in a variable and treatment. Pls see my example below

CUR cursor is
Select sql_stmt sql1 - extract the sql to run
RTA;

Open p_cursor for sql1; -Open the ref cursor
loop
look for p_cursor in? * -as the result set does not know initially how to declare a variable for it *.
output p_cursor % notfound;
-the results of the process
end loop;

Help, please. Hope I'm clear with my question. If not, please let me know

Oracle says:
Hi all

My requirement is as below
(1) the query to run is stored in a table because the query vary each time
(2) execution of the query and treat it

As the query could be of any table that I'm stuck on go get the query in a variable and treatment. Pls see my example below

CUR cursor is
Select sql_stmt sql1 - extract the sql to run
RTA;

Open p_cursor for sql1; -Open the ref cursor
loop
look for p_cursor in? * -as the result set does not know initially how to declare a variable for it *.
output p_cursor % notfound;
-the results of the process
end loop;

Help, please. Hope I'm clear with my question. If not, please let me know

Storage of queries in a table? This looks like a bad design, not to mention the possibility of SQL injection and causing ALL of your code to be written to be dynamic, where a nightmare to debug. Ouch!

You will not be able to do with a ref cursor if you don't know what to expect as the columns returned.
You can use the DBMS_SQL package and describe the query so that you can find on the columns and data types in the results... example of this package... (my example standard production CSV files)...

-----

As user sys:

CREATE OR REPLACE DIRECTORY TEST_DIR AS '\tmp\myfiles'
/
GRANT READ, WRITE ON DIRECTORY TEST_DIR TO myuser
/

As myuser:

CREATE OR REPLACE PROCEDURE run_query(p_sql IN VARCHAR2
                                     ,p_dir IN VARCHAR2
                                     ,p_header_file IN VARCHAR2
                                     ,p_data_file IN VARCHAR2 := NULL) IS
  v_finaltxt  VARCHAR2(4000);
  v_v_val     VARCHAR2(4000);
  v_n_val     NUMBER;
  v_d_val     DATE;
  v_ret       NUMBER;
  c           NUMBER;
  d           NUMBER;
  col_cnt     INTEGER;
  f           BOOLEAN;
  rec_tab     DBMS_SQL.DESC_TAB;
  col_num     NUMBER;
  v_fh        UTL_FILE.FILE_TYPE;
  v_samefile  BOOLEAN := (NVL(p_data_file,p_header_file) = p_header_file);
BEGIN
  c := DBMS_SQL.OPEN_CURSOR;
  DBMS_SQL.PARSE(c, p_sql, DBMS_SQL.NATIVE);
  d := DBMS_SQL.EXECUTE(c);
  DBMS_SQL.DESCRIBE_COLUMNS(c, col_cnt, rec_tab);
  FOR j in 1..col_cnt
  LOOP
    CASE rec_tab(j).col_type
      WHEN 1 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
      WHEN 2 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_n_val);
      WHEN 12 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_d_val);
    ELSE
      DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
    END CASE;
  END LOOP;
  -- This part outputs the HEADER
  v_fh := UTL_FILE.FOPEN(upper(p_dir),p_header_file,'w',32767);
  FOR j in 1..col_cnt
  LOOP
    v_finaltxt := ltrim(v_finaltxt||','||lower(rec_tab(j).col_name),',');
  END LOOP;
  --  DBMS_OUTPUT.PUT_LINE(v_finaltxt);
  UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
  IF NOT v_samefile THEN
    UTL_FILE.FCLOSE(v_fh);
  END IF;
  --
  -- This part outputs the DATA
  IF NOT v_samefile THEN
    v_fh := UTL_FILE.FOPEN(upper(p_dir),p_data_file,'w',32767);
  END IF;
  LOOP
    v_ret := DBMS_SQL.FETCH_ROWS(c);
    EXIT WHEN v_ret = 0;
    v_finaltxt := NULL;
    FOR j in 1..col_cnt
    LOOP
      CASE rec_tab(j).col_type
        WHEN 1 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_v_val);
                    v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
        WHEN 2 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_n_val);
                    v_finaltxt := ltrim(v_finaltxt||','||v_n_val,',');
        WHEN 12 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_d_val);
                    v_finaltxt := ltrim(v_finaltxt||','||to_char(v_d_val,'DD/MM/YYYY HH24:MI:SS'),',');
      ELSE
        v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
      END CASE;
    END LOOP;
  --  DBMS_OUTPUT.PUT_LINE(v_finaltxt);
    UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
  END LOOP;
  UTL_FILE.FCLOSE(v_fh);
  DBMS_SQL.CLOSE_CURSOR(c);
END;

This allows the header line and the data to write into files separate if necessary.

for example

SQL> exec run_query('select * from emp','TEST_DIR','output.txt');

PL/SQL procedure successfully completed.

Output.txt file contains:

empno,ename,job,mgr,hiredate,sal,comm,deptno
7369,"SMITH","CLERK",7902,17/12/1980 00:00:00,800,,20
7499,"ALLEN","SALESMAN",7698,20/02/1981 00:00:00,1600,300,30
7521,"WARD","SALESMAN",7698,22/02/1981 00:00:00,1250,500,30
7566,"JONES","MANAGER",7839,02/04/1981 00:00:00,2975,,20
7654,"MARTIN","SALESMAN",7698,28/09/1981 00:00:00,1250,1400,30
7698,"BLAKE","MANAGER",7839,01/05/1981 00:00:00,2850,,30
7782,"CLARK","MANAGER",7839,09/06/1981 00:00:00,2450,,10
7788,"SCOTT","ANALYST",7566,19/04/1987 00:00:00,3000,,20
7839,"KING","PRESIDENT",,17/11/1981 00:00:00,5000,,10
7844,"TURNER","SALESMAN",7698,08/09/1981 00:00:00,1500,0,30
7876,"ADAMS","CLERK",7788,23/05/1987 00:00:00,1100,,20
7900,"JAMES","CLERK",7698,03/12/1981 00:00:00,950,,30
7902,"FORD","ANALYST",7566,03/12/1981 00:00:00,3000,,20
7934,"MILLER","CLERK",7782,23/01/1982 00:00:00,1300,,10

The procedure allows for the header and the data to separate files if necessary. Just by specifying the file name "header" will put the header and the data in a single file.

Adapt to the exit of styles and different types of data are needed.

REF Cursor creating CSV files

Hi guys

I am writing a package to create several different CVS files of the database.
I created a procedure for each files CVS to be created within the package.
I set the cursor for each file to each intervention.
Read slider and concatenate all the fields in a large chain of recording and write it to the file using the UTL_FILE utility.

Is there a way I can create a common procedure and pass all other cases, file_name as a parameter and concatenate all the fields and records and write it to the file? I think the use of the REF cursor, but the problem is the cursor query is different for each file. Some files has 2 columns and some 200 columns.
No idea how to make this work for any format?

Your help will be very appreciated.

Thanks and greetings

Vijay

Here is a generic procedure, I used for my part in the past...

As user sys:

CREATE OR REPLACE DIRECTORY TEST_DIR AS '\tmp\myfiles'
/
GRANT READ, WRITE ON DIRECTORY TEST_DIR TO myuser
/

As myuser:

CREATE OR REPLACE PROCEDURE run_query(p_sql IN VARCHAR2
                                     ,p_dir IN VARCHAR2
                                     ,p_header_file IN VARCHAR2
                                     ,p_data_file IN VARCHAR2 := NULL) IS
  v_finaltxt  VARCHAR2(4000);
  v_v_val     VARCHAR2(4000);
  v_n_val     NUMBER;
  v_d_val     DATE;
  v_ret       NUMBER;
  c           NUMBER;
  d           NUMBER;
  col_cnt     INTEGER;
  f           BOOLEAN;
  rec_tab     DBMS_SQL.DESC_TAB;
  col_num     NUMBER;
  v_fh        UTL_FILE.FILE_TYPE;
  v_samefile  BOOLEAN := (NVL(p_data_file,p_header_file) = p_header_file);
BEGIN
  c := DBMS_SQL.OPEN_CURSOR;
  DBMS_SQL.PARSE(c, p_sql, DBMS_SQL.NATIVE);
  d := DBMS_SQL.EXECUTE(c);
  DBMS_SQL.DESCRIBE_COLUMNS(c, col_cnt, rec_tab);
  FOR j in 1..col_cnt
  LOOP
    CASE rec_tab(j).col_type
      WHEN 1 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
      WHEN 2 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_n_val);
      WHEN 12 THEN DBMS_SQL.DEFINE_COLUMN(c,j,v_d_val);
    ELSE
      DBMS_SQL.DEFINE_COLUMN(c,j,v_v_val,2000);
    END CASE;
  END LOOP;
  -- This part outputs the HEADER
  v_fh := UTL_FILE.FOPEN(upper(p_dir),p_header_file,'w',32767);
  FOR j in 1..col_cnt
  LOOP
    v_finaltxt := ltrim(v_finaltxt||','||lower(rec_tab(j).col_name),',');
  END LOOP;
  --  DBMS_OUTPUT.PUT_LINE(v_finaltxt);
  UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
  IF NOT v_samefile THEN
    UTL_FILE.FCLOSE(v_fh);
  END IF;
  --
  -- This part outputs the DATA
  IF NOT v_samefile THEN
    v_fh := UTL_FILE.FOPEN(upper(p_dir),p_data_file,'w',32767);
  END IF;
  LOOP
    v_ret := DBMS_SQL.FETCH_ROWS(c);
    EXIT WHEN v_ret = 0;
    v_finaltxt := NULL;
    FOR j in 1..col_cnt
    LOOP
      CASE rec_tab(j).col_type
        WHEN 1 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_v_val);
                    v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
        WHEN 2 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_n_val);
                    v_finaltxt := ltrim(v_finaltxt||','||v_n_val,',');
        WHEN 12 THEN DBMS_SQL.COLUMN_VALUE(c,j,v_d_val);
                    v_finaltxt := ltrim(v_finaltxt||','||to_char(v_d_val,'DD/MM/YYYY HH24:MI:SS'),',');
      ELSE
        v_finaltxt := ltrim(v_finaltxt||',"'||v_v_val||'"',',');
      END CASE;
    END LOOP;
  --  DBMS_OUTPUT.PUT_LINE(v_finaltxt);
    UTL_FILE.PUT_LINE(v_fh, v_finaltxt);
  END LOOP;
  UTL_FILE.FCLOSE(v_fh);
  DBMS_SQL.CLOSE_CURSOR(c);
END;

This allows the header line and the data to write into files separate if necessary.

for example

SQL> exec run_query('select * from emp','TEST_DIR','output.txt');

PL/SQL procedure successfully completed.

Output.txt file contains:

empno,ename,job,mgr,hiredate,sal,comm,deptno
7369,"SMITH","CLERK",7902,17/12/1980 00:00:00,800,,20
7499,"ALLEN","SALESMAN",7698,20/02/1981 00:00:00,1600,300,30
7521,"WARD","SALESMAN",7698,22/02/1981 00:00:00,1250,500,30
7566,"JONES","MANAGER",7839,02/04/1981 00:00:00,2975,,20
7654,"MARTIN","SALESMAN",7698,28/09/1981 00:00:00,1250,1400,30
7698,"BLAKE","MANAGER",7839,01/05/1981 00:00:00,2850,,30
7782,"CLARK","MANAGER",7839,09/06/1981 00:00:00,2450,,10
7788,"SCOTT","ANALYST",7566,19/04/1987 00:00:00,3000,,20
7839,"KING","PRESIDENT",,17/11/1981 00:00:00,5000,,10
7844,"TURNER","SALESMAN",7698,08/09/1981 00:00:00,1500,0,30
7876,"ADAMS","CLERK",7788,23/05/1987 00:00:00,1100,,20
7900,"JAMES","CLERK",7698,03/12/1981 00:00:00,950,,30
7902,"FORD","ANALYST",7566,03/12/1981 00:00:00,3000,,20
7934,"MILLER","CLERK",7782,23/01/1982 00:00:00,1300,,10

The procedure allows for the header and the data to separate files if necessary. Just by specifying the file name "header" will put the header and the data in a single file.

Adapt to the exit of styles and different types of data are needed.

A common type of save data for a weak Ref Cursor
Hi all

I am currently using a weak Ref Cursor.

I just want to know if we have any data in the record who can point to the ref cursor how to record data of type point to a normal cursor.

As if the ref cursor points to select * emp then data registration type must store the information of emp.
Even if it says to select * dept so the same data record type must store information dept.

Appreciate your input on this one.

Thank you
Madhu K.
Low Refcursor didn't rowtype. There is no way to get the information in column refcursor low before 11g. If you're on 11G you can convert refcursor to cursor DBMS_SQL, then use DBMS_SQL. DESCRIBE for information on columns and slider back to refcursor converst DBMS_SQL.

SY.

Casting table PL/SQL for the type of existing table and back ref cursor

Hello

I have the problem of casting a pl/sql table for the type of an existing table and turning the ref cursor to the application. Casting a ref cursor back and number of pl/sql table works well.

Declarant

< strong > TYPE type_table_name IS TABLE OF THE package_name.table_name%ROWTYPE; < facilities >

within the stored procedure, fill in a table of this type temp_table_name and returning the ref cursor help

< strong > results OPEN to SELECT * FROM TABLE (CAST (temp_table_name AS type_table_name)); < facilities >

generates an error. type_table_name is unknown in this distribution. According to me, this happens because of the declaration of the type locally.

Statement type_table_name inside the package specification does not work neither. Incredible, cast to the said dbms_sql.number_table to specify ref cursor back and dbms_sql package works very well!

< strong > CREATE TYPE type_table_name IS TABLE OF THE package_name.table_name%ROWTYPE; < facilities > deals without any error but creates an invalid type complain a reference to package_name.table_name

I don't want to declare every column in the table in type_table_name, because any change the table_name table would result in an inconsistent type_table_name.

Thanks in advance!

Edited by: user6014545 the 20.10.2008 01:04

In any case you are right that there is a problem around anchorage (or maintaining) types of objects persistent to match the table structures, they may represent.

In the case you describe, you might be better off just open the refcursor immediately the using one of the techniques described in the http://www.williamrobertson.net/documents/comma-separated.html to manage the delimited list.

In the more general case where the line of treatment is necessary, you may make the pipeline functions.

Oracle Database 10g Express Edition Release 10.2.0.1.0 - Production

SQL> CREATE TABLE table_name
  2  AS
  3     SELECT ename column_name
  4     FROM   emps;

Table created.

SQL> CREATE OR REPLACE PACKAGE package_name
  2  AS
  3     TYPE type_name IS TABLE OF table_name%ROWTYPE;
  4
  5     FUNCTION function_name_pipelined (
  6        parameter_name IN VARCHAR2)
  7        RETURN type_name PIPELINED;
  8
  9     FUNCTION function_name_refcursor (
 10        parameter_name IN VARCHAR2)
 11        RETURN sys_refcursor;
 12  END package_name;
 13  /

Package created.

SQL> CREATE OR REPLACE PACKAGE BODY package_name
  2  AS
  3     FUNCTION function_name_pipelined (
  4        parameter_name IN VARCHAR2)
  5        RETURN type_name PIPELINED
  6     IS
  7     BEGIN
  8        FOR record_name IN (
  9           SELECT table_alias.*
 10           FROM   table_name table_alias
 11           WHERE  table_alias.column_name LIKE parameter_name) LOOP
 12
 13           PIPE ROW (record_name);
 14        END LOOP;
 15
 16        RETURN;
 17     END function_name_pipelined;
 18
 19     FUNCTION function_name_refcursor (
 20        parameter_name IN VARCHAR2)
 21        RETURN sys_refcursor
 22     IS
 23        variable_name sys_refcursor;
 24     BEGIN
 25        OPEN variable_name FOR
 26           SELECT table_alias.*
 27           FROM   TABLE (package_name.function_name_pipelined (
 28                     parameter_name)) table_alias;
 29
 30        RETURN variable_name;
 31     END function_name_refcursor;
 32  END package_name;
 33  /

Package body created.

SQL> VARIABLE variable_name REFCURSOR;
SQL> SET AUTOPRINT ON;
SQL> BEGIN
  2     :variable_name := package_name.function_name_refcursor ('%A%');
  3  END;
  4  /

PL/SQL procedure successfully completed.

COLUMN_NAME
-----------
ALLEN
WARD
MARTIN
BLAKE
CLARK
ADAMS
JAMES

7 rows selected.

SQL> ALTER TABLE table_name ADD (new_column_name VARCHAR2 (1) DEFAULT 'X');

Table altered.

SQL> BEGIN
  2     :variable_name := package_name.function_name_refcursor ('%A%');
  3  END;
  4  /

PL/SQL procedure successfully completed.

COLUMN_NAME NEW_COLUMN_NAME
----------- ---------------
ALLEN       X
WARD        X
MARTIN      X
BLAKE       X
CLARK       X
ADAMS       X
JAMES       X

7 rows selected.

SQL>

REP-0737: must be a function of return type 'ref cursor.

Hi all
I have create a ref cursor query in reports 10 g. But it is giving error REP-0737: must be a function of return type 'ref cursor.
Here is my code
```
function QR_1RefCurDS return sys_refcursor is

 My_Cur Sys_Refcursor;
begin
  Open My_Cur for select * from scott.emp order by deptno;
  return My_Cur
end;
```
fate of the screen.

Oracle Forms/Reports has a complete PL/SQL engine and (only) the SQL parser.

However, the engine of forms/States PL / SQL and SQL Analyzer are at a level that was in the Oracle 8.0 database.

So, in the forms/States functions/procedures and forms/States triggers, you can not use SQL commands that did not exist in the 8.0 database.

The predefined SYS_REFCURSOR type is introduced in Oracle 9i.

Use this:

PACKAGE test_rc IS

TYPE of rc_type IS REF CURSOR RETURN emp % ROWTYPE;

END;

FUNCTION RETURN QR_1RefCurDS Test_rc.rc_type IS

test_rc.rc_type RC;

BEGIN

OPEN the RC to SELECT * FROM emp;

RETURN rc;

END;

Kind regards

Zlatko

Ref Cursor remote procedure fails

Remote database server Oracle 9iR2 1

Local database server Oracle 10 g 2 2

Remote procedure:

CREATE OR REPLACE PROCEDURE p_get_results (   i_query   IN   VARCHAR2
                                            , o_refc    OUT  sys_refcursor
                                          )
AS
BEGIN
    IF ( i_query IS NULL )
    THEN
         RAISE_APPLICATION_ERROR(-20001,'The paramter i_query cannot be null') ;
    END IF ;


    OPEN o_refc FOR i_query ;
    
    EXCEPTION
        WHEN   others   THEN
             RAISE ;
END p_get_results ;
/

Local PL/SQL block

SQL> var i_query varchar2(100)
SQL> var o_refc refcursor
SQL> exec :i_query := 'select count(*) from oo_attrs'


SQL> exec p_get_results@demo_oo2 (:i_query,:o_refc)


ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-01001: invalid cursor

Check the link works and request db:

SQL> select count(*) from oo_attrs@demo_oo2;

  COUNT(*)
----------
       225

Am I missing something here?

Am I missing something here?

Yes - you cannot use REF CURSOR over links to db.

Ref cursor error message

Hello expert;
I have a function that returns a ref cursor, but the function may not return anything. I would like to know what is the best way to manage the error message
ORA-06503: PL/SQL: function returned no value - slider Ref
.. Please see below.
```
function f_de return latest_cur is
my_l_cur l_cur;

begin
open my_l_cur for
select max(dateadded) as dateadded
from tbl_test;
end;
```
I was wondering what is the best way to manage. I know I could use a count, and if the number is greater than 0, manipulate, but I was looking for the best way to manage it.

user13328581 wrote:

Hello expert;

I have a function that returns a ref cursor, but the function may not return anything. I would like to know what is the best way to manage the error message

ORA-06503: PL/SQL: function returned no value - slider Ref

.. Please see below.
1. latest_cur the f_de function return is
2. my_l_cur l_cur;
3. Start
4. Open the my_l_cur for
5. Select max (dateadded) as dateadded
6. of tbl_test;
7. end;
I was wondering what is the best way to manage. I know I could use a count, and if the number is greater than 0, manipulate, but I was looking for the best way to manage it.

by definition a FUNCTION returns a value, but your code isn't working; Therefore, the error is thrown.

RETURN MY_L_CUR;

the top line should take place before the END; statement.

Apex and accept Ref Cursor?

Apex and accept Ref Cursor?
Apex and accept objects?
can someone help me please.

Hi Nani4850,

Nani4850 wrote:

Apex and accept Ref Cursor?

Apex and accept objects?

The language of business for APEX is PL/SQL, so yes you can use REF CURSOR and pass objects to you packaged functions/procedures.

How does this relate to Oracle APEX?

Please explain what you plan to use a REF CURSOR in the APEX.

Kind regards

Kiran

Ref cursor vs dbms_sql

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