Stored Procedure outputting String and Cursor - sql

Hey guys, I have a stored procedure that outputs just the column of a table. Instead, I'd like to have 'There are' [column count] 'students.' as an output. Example below.
CREATE OR REPLACE PROCEDURE active_students (arc in out sys_refcursor)
as
begin
open arc for select count(*) from student;
end;
This generates
Count(*)
30
would like it to read
There are 30 students.

Use:
CREATE OR REPLACE PROCEDURE JSU4290M.active_students (arc in out sys_refcursor)
AS
BEGIN
OPEN arc FOR
SELECT 'There are '|| COUNT(*) ||' students.' AS col
FROM STUDENT;
END;
The double pipe (||) is Oracle's (and now ANSI standard) means of concatenating strings. Oracle will implicitly convert the integer value to a string.

Related

Calling table name IN parameter for procedure and outputting every column name in that table

Sorry if this is not a good question, I feel like it should be simple but I'm not getting the result I want :(
I created the a stored procedure that prints out all of my table names in USER_TABLES. Now what I want to do now is call another procedure within the first procedure to output all of the columns in my tables.
What I have:
create or replace PROCEDURE ColumnNames(
newColumn.Table_Name IN varchar2
)
AS
CURSOR newColumn IS
SELECT COLUMN_NAME
FROM USER_TABLES;
CurrentRow newColumn%ROWTYPE;
BEGIN
FOR CurrentRow IN newColumn LOOP
DBMS_OUTPUT.PUT_LINE(CurrentRow.Column_Name);
END LOOP;
END;
/
Edited to add error message:
Error(3,10): PLS-00103: Encountered the symbol "." when expecting one of the following:
in out ... long double ref char time timestamp interval date binary
Thanks for your help!
Use user_tab_columns instead of user_tables.
Variable newColumn.Table_Name does nothing in your code and has incorrect name(contains dot symbol)
Also cursor and variable declaration are excessive in current case.
If you need to print all column names for particular table you can use
create or replace procedure print_columns(tab_name in varchar2) is
begin
for col in (select column_name from user_tab_columns where table_name = tab_name) loop
dbms_output.put_line(col.column_name);
end loop;
end;
/

How to make a function that takes code like "SELECT * FROM SOME_TABLE" as an input and returns a table as an output?

I want to create a function that takes some code as an input (e.g. Select * FROM SOME_TABLE) and returns the result of a query as an output.
I want to use it in procedures in order to return tables as a result.
It should look like this:
BEGIN
--some procedure code
CREATE TABLE SOME_TABLE as Select * FROM ...;
Select * FROM table(my_function('Select * FROM SOME_TABLE'));
END;
Important tips:
The resulting table can have multiple columns, from 1 to +inft
The resulting table can have multiple rows, from 1 to +inft
So the size of a table can be both very small or very large.
The input query can have several where, having, partition, and other Oracle constructions.
I want to have a table as an output, not DBMS_OUTPUT.
I can't install any modules/applications, or use other languages hints. However, I can manually create types, functions, procedures.
I tried to search in the net but could not find a solution that meets all my expectations. The best link I've found was this:
https://sqljana.wordpress.com/2017/01/22/oracle-return-select-statement-results-like-sql-server-sps-using-pipelined-functions/
DBMS_SQL.RETURN_RESULT works if your "code" is a select query
DECLARE
l_cur SYS_REFCURSOR;
l_query VARCHAR2(4000) := 'select * from SOME_TABLE';
BEGIN
OPEN l_cur for l_query;
DBMS_SQL.RETURN_RESULT(l_cur);
END;
/
you can create a function that has a string as parameter and return a cursor.
select statement you should pass as a string. in a function you can open a Cursor.
declare
v_sql varchar2(100) := 'select 1,2,3,4,5 from dual';
cur_ref SYS_REFCURSOR;
function get_data(in_sql in varchar2) return SYS_REFCURSOR
as
cur_ret SYS_REFCURSOR;
begin
OPEN cur_ret FOR in_sql;
return cur_ret;
end;
begin
:cur_ref := get_data(v_sql);
end ;
if your select statement is longer than 32K than you maybe should use a clob instead of varchar2 for your Parameter type. But you have to try that

Oracle SQL Developer, using dynamic SQL in function

I have the following script which contains a function named 'myFunction'. (declaration of types named rowValueTmp and rowValueTable are also attached for your information) Basically, I need to use a table name as an input parameter for myFunction. I found that I need to use dynamic SQL in order to use the table name as a parameter (Please correct me if there are alternative ways to do this). So the following code is what I have tried so far.
create or replace type rowValueTmp as object (
month number,
year number
);
/
create or replace type rowValueTable as table of rowValueTmp;
/
create or replace FUNCTION myFunction (TABLENAME in VARCHAR2)
return rowValueTable as
v_ret rowValueTable;
begin
execute immediate '
select rowValueTmp(month, year)
bulk collect into v_ret
from '||TABLENAME;
return v_ret;
end myFunction;
/
select * from table(myFunction('SCHEMA.TEST'));
But, this code gives me an error, and I assumed that this error is occurred because of using 'bulk collect' in execute immediate block.
ORA-03001: unimplemented feature
If I replace the content of execute immediate as the following, the above script is working..
select rowValueTmp(month, year)
bulk collect into v_ret
from SCHEMA.TEST;
Question
1] Is there any way(rather than Dynamic SQL) that I can use a table name as an input parameter for myFunction?
2] If I am not allowed to use bulk collect in execute immediate block, what do you suggest?
You can return values from execute immediately into a bulk collect:
CREATE OR REPLACE FUNCTION myfunction (tablename IN VARCHAR2)
RETURN rowvaluetable AS
v_ret rowvaluetable;
v_table VARCHAR2 (61) := DBMS_ASSERT.sql_object_name (tablename);
BEGIN
EXECUTE IMMEDIATE '
select rowValueTmp(month, year)
from ' || v_table
BULK COLLECT INTO v_ret;
RETURN v_ret;
END myfunction;
/
In the interest of an abundance of caution, I'd recommend using DBMS_ASSERT to validate the table parameter as well (as shown).

Displaying data through stored procedure

Create or replace procedure disp(pEMPLASTNAME varchar2)
IS
Row employee%rowtype;
begin
select * into row from employee where EMPLASTNAME=’pEMPLASTNAME’ ;
dbms_output.put_line('Name: '||Row.EMPID||' '|| Row.EMPNAME);
End;
/
BEGIN
disp(‘Mark’);
END;
/
Hello, I am trying to display data from a a table using stored procedures. The last name is passed as a parameter through the stored procedure and upon execution , the stored procedure should display all the rows which have the last name . Here is the error that i get; pls help! :-
SQL> BEGIN
disp('Mark');
END;
/
BEGIN
*
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at "TEST.DISP", line 5
ORA-06512: at line 2
No need of the quotes:
select * into row from employee where EMPLASTNAME=pEMPLASTNAME;
However, you may not have any data for that variable's value anyway (i.e. one day, it may happen)
That's why I recommend you catch the exception and treat it (see EXCEPTION block)
pd: it is a good practice to not use reserved words such as row. I recommend you name your variable another way.
I would suggest using a cursor to select all rows and then looping through the cursor to print the result:
Create or replace procedure disp(pEMPLASTNAME varchar2)
IS
Cursor row_select is
select EMPID, EMPNAME from employee where emplastname = pEMPLASTNAME;
-- and whatever columns you need to print, using * isn't good practice
begin
for item in row_select loop
dbms_output.put_line('Name: '||item.EMPID||' '|| item.EMPNAME);
end loop;
End;
/
BEGIN
disp(‘Mark’);
END;
/

trouble defining weakly defined ref cursor

I'm attempting to write a stored proc that takes in a number, n, and returns the first n results for a given query, exclusively locking those n rows. I'm a little new to SQL and I'm having a bit of difficulty matching data types correctly.
My package spec looks like this:
PACKAGE package IS
Type out_result_type is REF CURSOR;
PROCEDURE stored_proc
(in_n IN NUMBER DEFAULT 10,
out_list IN OUT out_result_type);
I then define the cursor in the procedure body, like so:
CURSOR OUT_RESULT_TYPE IS
SELECT a.id
FROM schema.table a
WHERE (some conditions) AND rownum <= in_n;
A bit later on I then try to extract the results of the cursor into the output variable:
OPEN OUT_RESULT_TYPE;
FETCH OUT_RESULT_TYPE INTO out_list; -- error on this line
CLOSE OUT_RESULT_TYPE;
But alas this code doesn't compile; oracle complains that out_list has already been defined with a conflicting data type. Any idea how I can resolve this issue? It's driving me crazy!
Thanks in advance.
CREATE OR REPLACE PACKAGE pkg_test
AS
TYPE tt_cur IS REF CURSOR;
PROCEDURE prc_cur (retval OUT tt_cur);
END;
CREATE OR REPLACE PACKAGE BODY pkg_test
AS
PROCEDURE prc_cur (retval OUT tt_cur)
AS
BEGIN
OPEN retval
FOR
SELECT *
FROM dual;
END;
END;
If you want to lock, use:
CREATE OR REPLACE PACKAGE BODY pkg_test
AS
PROCEDURE prc_cur (retval OUT tt_cur)
AS
BEGIN
OPEN retval
FOR
SELECT a.id
FROM schema.table a
WHERE (some conditions)
AND rownum <= in_n
ORDER BY
column
-- Never forget ORDER BY!
FOR UPDATE;
END;
END;
Two remarks:
A cursor doesn't lock.
You don't have to do Type out_result_type is REF CURSOR;, use default type sys_refcursor. See here: Oracle - How to have an out ref cursor parameter in a stored procedure?
Your out_list must be of wrong type. Consider (script run on 10.2.0.3):
CREATE TABLE t AS SELECT ROWNUM ID FROM all_objects WHERE ROWNUM <= 100;
CREATE OR REPLACE PACKAGE cursor_pck AS
TYPE out_result_type is REF CURSOR;
PROCEDURE stored_proc (p_in IN NUMBER DEFAULT 10,
p_out_list IN OUT out_result_type);
END cursor_pck;
/
If you want to select and lock the rows at the same time you would use the FOR UPDATE clause:
CREATE OR REPLACE PACKAGE BODY cursor_pck AS
PROCEDURE stored_proc (p_in IN NUMBER DEFAULT 10,
p_out_list IN OUT out_result_type) IS
BEGIN
OPEN p_out_list FOR SELECT a.id FROM t a WHERE ROWNUM <= p_in FOR UPDATE;
END stored_proc;
END cursor_pck;
/
With the following setup, you will call the procedure like this:
SQL> SET SERVEROUTPUT ON;
SQL> DECLARE
2 l_cursor cursor_pck.out_result_type;
3 l_id t.id%TYPE;
4 BEGIN
5 cursor_pck.stored_proc(3, l_cursor);
6 LOOP
7 FETCH l_cursor INTO l_id;
8 EXIT WHEN l_cursor%NOTFOUND;
9 dbms_output.put_line(l_id);
10 END LOOP;
11 END;
12 /
1
2
3
PL/SQL procedure successfully completed
This is not going to work the way it's written, because
out_list expects a cursor, not a cursor result.
The name out_result_type is already used for a type, so you can't redefine it to be a cursor in the same scope.
Oracle provides a pre-defined weak reference cursor: sys_refcursor. In usage it would look like:
CREATE OR REPLACE PACKAGE pkg_test
AS
PROCEDURE prc_cur (p_retval OUT sys_refcursor,
p_lookup IN VARCHAR2);
END pkg_test;
CREATE OR REPLACE PACKAGE BODY pkg_test
AS
PROCEDURE prc_cur(p_retval OUT sys_refcursor
p_lookup IN VARCHAR2)
IS
BEGIN
OPEN retval FOR SELECT a.value
FROM tblname a
WHERE a.id <= p_lookup;
END prc_cur;
END pkg_test;
This saves you the trouble of needing to declare a type. The sys_refcursor is a pointer to a result set from an open cursor. If you are familiar with Java, it's the same concept as the java.sql.ResultSet object which provides a way to get at the results of a query.