I have PL/SQL function which is dynamically creating select statement an return this statement as varchar.Because I need this statement work dynamically(each time return different column count/name).For example it can return this select
'select id,name,currency,note from tabel t where t.id in(1,2,3,4,5,6);'
And I have another function must use this select statement result.
But the second select statement return that this string and cannot execute this select statement.
How can make first function return result as sql ?
Provided the caller knows the structure of the result:
CREATE OR REPLACE PROCEDURE execute_query(query IN VARCHAR2)
TYPE cur_typ IS REF CURSOR;
c cur_typ;
ID NUMBER;
Name VARCHAR2(20);
Currency VARCHAR2(20);
Note VARCHAR2(200);
BEGIN
OPEN c FOR query;
LOOP
FETCH c INTO ID, Name, Currency, Note;
EXIT WHEN c%NOTFOUND;
....
END LOOP;
CLOSE c;
END;
/
Use
EXECUTE IMMEDIATE Statement
as said in documentation:
https://docs.oracle.com/cd/B13789_01/appdev.101/b10807/13_elems017.htm
Related
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
I have this table :
| Pattern |
----------------------
|category |varchar|
|patternexpr |varchar|
For example in this table I can have a category ISBN and its pattern to recognize it.
I want to create a procedure which takes three arguments : a table T, one of its column C and a category. I want to print every rows in column C in T table which respect the pattern associated.
This is what I did (Updated with the correct answer):
CREATE OR REPLACE PROCEDURE Recognize(T varchar,C varchar,catego varchar)
IS
v_patt Pattern.CATEGOR%Type;
BEGIN
SELECT patternexpr INTO v_patt
FROM Pattern WHERE CATEGOR=catego;
FOR myrow IN (SELECT C FROM T WHERE REGEXP_LIKE(C, v_patt) LOOP
dbms_output.put_line(myrow.C);
END LOOP;
END;
/
How can I declare a cursor to print my result without knowing the value of my variable patt in the "DECLARE" place ? Should I add another declare and begin...end bloc after the first query ? What is the best way to do it ?
(I'm working on Oracle SGBD)
Use REF CURSOR to fetch records for this purpose.
CREATE OR REPLACE PROCEDURE Recognize(
T VARCHAR2,
C VARCHAR2,
catego VARCHAR2)
IS
v_patt Pattern.CATEGOR%Type;
v_cur_txt VARCHAR2(400);
TYPE cur_type
IS
REF
CURSOR;
v_cur cur_type;
v_c VARCHAR2(20);
BEGIN
SELECT patternexpr INTO v_patt FROM Pattern WHERE CATEGOR=catego;
v_cur_txt := 'SELECT '||C||' FROM '|| T ||' WHERE REGEXP_LIKE('||C||', '''||v_patt||''')';
OPEN v_cur FOR v_cur_txt;
LOOP
FETCH v_cur INTO v_c;
EXIT
WHEN v_cur%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(v_c);
END LOOP;
CLOSE v_cur;
END;
/
NOTE: : Include proper EXCEPTION handling in your code for NO_DATA_FOUND etc.Also as per Nicholas , make some validations by using dbms_assert package
In Oracle, you don't need an explicit cursor:
for myrow in (select c from t where regexp_like(c, patt) loop
dbms_output.put_line(myrow.c);
end loop;
I would call the pattern variable something like v_patt; that way, declared variables don't get confused with column names.
What would be the PL/SQL equivalent of this SQL query:
SELECT * FROM table(OWNER.PACKAGE.get_exam('123456789'));
This is the Function that I am trying to call:
FUNCTION get_exam(id IN VARCHAR2)
RETURN ab_assign_v1
IS
CURSOR c_exams(cid VARCHAR2) IS
SELECT t_api_exam_v1(
sei.person_id, --unique id
l.description --loc description
)
FROM my_view sei
JOIN loc l
ON sei.loc_code = l.loc_code
v_collection ab_assign_v1;
BEGIN
OPEN c_exams(id);
FETCH c_exams BULK COLLECT INTO v_collection;
CLOSE c_exams;
RETURN v_collection;
EXCEPTION
WHEN OTHERS THEN
error_a1.raise_error(SQLCODE, SQLERRM);
END get_exam;
Hope this helps.
DECLARE
lv <COLLECTION_NAME>;
BEGIN
lv:= OWNER.PACKAGE.get_exam('123456789');
dbms_output.put_line(lv.COUNT);
END;
/
Assuming that you want to return the result of a function :
select owner.package.get_exam('123456789') from table
Your function returns a nested table type. You simply need to declare a variable of that type, and assign to it as you would if it were a scalar:
declare
l_coll your_collection_type;
begin
l_coll := OWNER.PACKAGE.get_exam('123456789');
end;
/
In this example your_collection_type is a placeholder for whatever object your function actually returns.
" I am getting this error: PLS-00201: identifier 'ab_assign_v1' must be declared "
ab_assign_v1 is the type used by your function. From the code posted in your revised question it seems that type is in the same schema which owns the package with the function. However your original pseudo-code prefixes the call with the schema name. So, putting two and two together, you need to revise the variable declaration to include the schema too. (You may need to grant EXECUTE on it too, if you haven't done this already).
declare
l_coll OWNER.ab_assign_v1;
begin
l_coll := OWNER.PACKAGE.get_exam('123456789');
end;
/
I created a function that should return the max id from a table(parameter)
CREATE OR REPLACE FUNCTION getmaxid
(
P_TABLE IN VARCHAR2
)
RETURN NUMBER IS
v_maxId NUMBER(38);
BEGIN
SELECT MAX(id) INTO v_maxId FROM P_TABLE;
RETURN v_maxId;
END getmaxid
However, i keep getting the error message "ORA-00942: table or view does not exist" on this line:
SELECT MAX(id) INTO v_maxId FROM P_TABLE;
Like explained earlier, you need to use dynamic SQL to perform the operation. In this case, p_table is a variable. The solution to this is to build a string that will contain the SQL and dynamically execute it one you've build the query.
The example below uses, DUAL, but the table name is arbitrary.
Here is what you're looking for, take the function outside of the block, I left it like this so that you can test it..
DECLARE
FUNCTION getmaxid (p_table IN VARCHAR2)
RETURN NUMBER
IS
v_maxid NUMBER (38);
v_select VARCHAR2 (200);
cnt SYS_REFCURSOR;
BEGIN
v_select := 'SELECT COUNT(*) FROM ' || p_table;
DBMS_OUTPUT.put_line (v_select);
EXECUTE IMMEDIATE v_select INTO v_maxid;
RETURN v_maxid;
END getmaxid;
BEGIN
DBMS_OUTPUT.put_line (getmaxid ('DUAL'));
END;
What i want: i have a table with queries, i need to make a query that runs one of the values in that column
ie:
queryname query
Chips select * from chips_table c join all_stores s on c.id=s.id where s.loc>213...
... ...
I know i want the result from the above query, how can i run a procedure or script or view or whatnot like
getme(Chips)
and this to run the
select * from chips_table c join all_stores s on c.id=s.id where s.loc>213...
Depends on what you want to do with the results afterwards, but for PL/SQL processing you may use something like:
-- Function to open and return the cursor for the query based on query name
CREATE OR REPLACE FUNCTION get_cursor (in_queryname IN VARCHAR2)
RETURN SYS_REFCURSOR
IS
c_query SYS_REFCURSOR;
v_query queries.query%type;
BEGIN
SELECT query INTO v_query FROM queries WHERE queryname = in_queryname;
OPEN c_query FOR v_query;
RETURN c_query;
END;
-- Example of use
DECLARE
c_query SYS_REFCURSOR;
some_variable INTEGER;
another_variable INTEGER;
BEGIN
LOOP
FETCH c_query INTO some_variable, another_variable;
EXIT WHEN c_query%NOTFOUND;
-- Do someting!
END LOOP;
CLOSE c_query;
EXCEPTION WHEN no_data_found THEN
NULL; -- Log the error!
END;