I created a procedure to calculate the hashcode of a record (complete line of a table) and then update a column with the calculated hashcode number.
Here's my code at this point (which is based on some info I manage to gather from Google):
CREATE OR REPLACE PROCEDURE calcHashCode (inputTableString IN varchar2) IS
c_data varchar2(3000); --QUERY
c_cursor sys_refcursor; --CURSOR
c_record inputTableString%rowtype; -- Problem is here
BEGIN
c_data := 'SELECT * FROM ' || inputTableString;
OPEN c_cursor for c_data;
LOOP
FETCH c_cursor INTO c_record;
EXIT WHEN c_cursor%notfound;
-- will do stuff here with the records
dbms_output.put_line('stuff');
END LOOP;
CLOSE c_cursor;
END;
/
SHOW ERRORS
4/13 PLS-00310: with %ROWTYPE attribute, 'INPUTTABELA' must name a table, cursor or cursor-variable
4/13 PL/SQL: Item ignored
11/25 PLS-00320: the declaration of the type of this expression is incomplete or malformed
11/5 PL/SQL: SQL Statement ignored
So, my idea (for the final stage of the procedure) is to iterate through out the records, build a string with and then calculate the hashcode. After that, I'll run the update instruction.
The thing is at this point using a varchar as an argument and I'm not being able to iterate through the table in order to get my concatenate records.
dynamic cursors are the ugliest...
the problem is with that section:
c_data varchar2(3000); --QUERY
c_cursor sys_refcursor; --CURSOR
c_record inputTableString%rowtype;
i used something like this:
TYPE t_data IS REF CURSOR;
cr_data t_data;
cr_data_rec inputTableString%ROWTYPE; --that table need to be exists in compile time
the rest are good i think
Have you considered pushing the whole declaration and loop into an anonymous block that will then get executed by EXECUTE IMMEDIATE? You can then simplify your looping construct to a simple FOR loop too.
I'm away from my database at the moment, so excuse any syntax glitches, but something like
CREATE OR REPLACE PROCEDURE calcHashCode (inputTableString IN varchar2) IS
c_data varchar2(30000); --QUERY
BEGIN
c_data := '
BEGIN
FOR aRec IN
(SELECT * FROM ' || inputTableString ||' )
LOOP
--do your stuff
END LOOP;
END';
execute immediate c_Data;
END;
/
It may not be pretty, and your "Stuff" may not easily be able to be fit into this construct, but it IS feasible
You can do all this kind of stuff with PL/SQL package DBMS_SQL, however it is definitely not for beginners and you should start with something easier.
Examples for DBMS_SQL
Related
I would like to create record from refcursor. My code:
set serveroutput on
DECLARE
c_curs SYS_REFCURSOR;
v_id NUMBER;
BEGIN
pck_prov.get_value_type_list (1, c_curs); --> procedure called here
-- I guess this is the place where record can be created from cursor.
LOOP
FETCH c_curs
INTO v_id;--instead of fetching into variable I would like to fetch into row
EXIT WHEN c_curs%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(v_id);--if fetching is done into row, only selected columns can be printed, like myrow.id
END LOOP;
CLOSE c_curs;
END;
Please note: I know how to create record from cursor which is defined with select statement as it is described here. What I don't know is how to use same technique for refcursors.
EDIT:
Code from here is just what I need, but it throws error:
set serveroutput on
VAR c_curs refcursor;
EXECUTE pck_prov.get_value_type_list(1, :c_curs);
BEGIN
FOR record_test IN :c_curs LOOP
dbms_output.put_line(record_test.id);
END LOOP;
END;
Error: error PLS-00456: item 'SQLDEVBIND1Z_1' is not a cursor.
Just to clarify question:
In my database there is around 200 packages.
Every package has several stored procedures inside - and usually each procedure is combined with columns from different tables. That is why it would be the best to have some dynamically created cursor, so I can make simple select just like in the example I've posted.
From Oracle 12.1 onward, you could use the DBMS_SQL.return_result procedure. SQL Plus displays the contents of implicit statement results automatically. So, rather than defining explicit ref cursor out parameters, the RETURN_RESULT procedure in the DBMS_SQL package allows you to pass them out implicitly.
DECLARE
c_curs SYS_REFCURSOR;
v_id NUMBER;
BEGIN
pck_prov.get_value_type_list (1, c_curs);
DBMS_SQL.return_result(c_curs); --> Passes ref cursor output implicitly
END;
/
In fact, no need of this separate PL/SQL block, you could add the DBMS_SQL.return_result(c_curs) statement in your original pck_prov.get_value_type_list procedure itself.
Just define a PL/SQL RECORD type that matches the cursor and FETCH into it.
DECLARE
c_curs SYS_REFCURSOR;
TYPE rec_t IS RECORD ( object_name VARCHAR2(30), object_type VARCHAR2(30) );
v_rec rec_t;
BEGIN
OPEN c_curs FOR
SELECT object_name,
object_type
FROM dba_objects
WHERE object_name like 'DBA%TAB%';
LOOP
FETCH c_curs
INTO v_rec;
EXIT WHEN c_curs%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(v_rec.object_name || ' - ' || v_rec.object_type);
END LOOP;
CLOSE c_curs;
END;
DBA_ADVISOR_SQLA_TABLES - VIEW
DBA_ADVISOR_SQLA_TABVOL - VIEW
DBA_ADVISOR_SQLW_TABLES - VIEW
DBA_ADVISOR_SQLW_TABVOL - VIEW
DBA_ALL_TABLES - VIEW
etc...
I want to create procedure, that will use cursor, which is the same for arbitrary tables. My current one looks like this:
create or replace
PROCEDURE
some_name(
p_talbe_name IN VARCHAR2,
p_chunk_size IN NUMBER,
p_row_limit IN NUMBER
) AS
CURSOR v_cur IS
SELECT common_column,
ora_hash(substr(common_column, 1, 15), p_chunk_size) as chunk_number
-- Here it can find the table!
FROM p_table_name;
TYPE t_sample IS TALBE OF v_cur%rowtype;
v_sample t_sample;
BEGIN
OPEN v_cur;
LOOP FETCH v_cur BULK COLLECT INTO v_sample LIMIT p_row_limit;
FORALL i IN v_sample.first .. v_sample.last
INSERT INTO chunks VALUES v_sample(i);
COMMIT;
EXIT WHEN v_cur%notfound;
END LOOP;
CLOSE v_cur;
END;
The problem is that it cannot find the table named p_table_name which I want to parametrize. The thing is that I need to create chunks based on hashes for common_column which exists in all intended tables. How to deal with that problem? Maybe there is the equivalent oracle code that will do the same thing? Then I need the same efficiency for the query. Thanks!
I would do this as a single insert-as-select statement, complicated only by the fact you're passing in the table_name, so we need to use dynamic sql.
I would do it something like:
CREATE OR REPLACE PROCEDURE some_name(p_table_name IN VARCHAR2,
p_chunk_size IN NUMBER,
p_row_limit IN NUMBER) AS
v_table_name VARCHAR2(32); -- 30 characters for the tablename, 2 for doublequotes in case of case sensitive names, e.g. "table_name"
v_insert_sql CLOB;
BEGIN
-- Sanitise the passed in table_name, to ensure it meets the rules for being an identifier name. This is to avoid SQL injection in the dynamic SQL
-- statement we'll be using later.
v_table_name := DBMS_ASSERT.ENQUOTE_LITERAL(p_table_name);
v_insert_sql := 'insert into chunks (common_column_name, chunk_number)'||CHR(10)|| -- replace the column names with the actual names of your chunks table columns.
'select common_column,'||CHR(10)||
' ora_hash(substr(common_column, 1, 15), :p_chunk_size) AS chunk_number'||CHR(10)||
'from '||v_table_name||CHR(10)||
'where rownum <= :p_row_limit';
-- Used for debug purposes, so you can see the definition of the statement that's going to be run.
-- Remove before putting the code in production / convert to proper logging code:
dbms_output.put_line(v_insert_sql);
-- Now run the statement:
EXECUTE IMMEDIATE v_insert_sql USING p_chunk_size, p_row_limit;
-- I've included the p_row_limit in the above statement, since I'm not sure if your original code loops through all the rows once it processes the
-- first p_row_limit rows. If you need to insert all rows from the p_table_name into the chunks table, remove the predicate from the insert sql and the extra bind variable passed into the execute immediate.
END some_name;
/
By using a single insert-as-select statement, you are using the most efficient way of doing the work. Doing the bulk collect (which you were using) would use up memory (storing the data in the array) and cause extra context switches between the PL/SQL and SQL engines that the insert-as-select statement avoids.
I am trying to create a stored procedure in Oracle and make a dynamic query work to get a bunch of records. I have read many examples but so far I can't get this to work unless I do this:
CREATE OR REPLACE PROCEDURE GiveMeResultSet(
v_par1 IN CHAR,
v_par2 IN CHAR,
v_par3 IN CHAR,
v_par4 IN VARCHAR2,
v_par5 IN VARCHAR2,
v_par6 IN VARCHAR2,
cur_typ OUT SYS_REFCURSOR)
IS
BEGIN
OPEN cur_typ FOR 'select * from complex_query';
--CLOSE cur_typ;
END;
And I am executing it this way:
var c refcursor;
execute GiveMeResultSet(null,null,null,null,null,null,:c);
print c;
This way I get the header names and the records from the query, but I am not closing the cursor that is fetching the results. If I close it then I get nothing at all. I guess leaving it open could cause some kind of memory leak problem at some point.
I have seen similar cases in Oracle documentation where they do something like this:
sql_stmt := 'SELECT * FROM emp';
OPEN emp_cv FOR sql_stmt;
LOOP
FETCH emp_cv INTO emp_rec;
EXIT WHEN emp_cv%NOTFOUND;
-- process record
END LOOP;
CLOSE emp_cv;
But I have no clue what goes on the "process record" part of the code which would allow to get the whole set of records at the end, plus that my record has a complex structure that doesn't fit with a fixed set of fields as in a table.
Can you please show me the proper way to do this?.
Thanks a lot.
ok CodeRoller, here is my sample code for a unspecified ref cursor:
Code of the Function which returns the ref cursor:
create or replace function test_ref_cursor(pi_sql_statement in varchar2) return SYS_REFCURSOR is
result_cursor SYS_REFCURSOR;
begin
open result_cursor for pi_sql_statement;
return result_cursor;
end;
Now, in the next step I use this function to get data from v$parameter:
declare
type t_my_cursor is ref cursor;
my_cursor t_my_cursor;
l_rec v$parameter%rowtype;
begin
my_cursor := test_ref_cursor('select * from v$parameter');
loop
fetch my_cursor into l_rec;
exit when my_cursor%notfound;
dbms_output.put_line(l_rec.name || ' = ' || l_rec.value);
end loop;
close my_cursor;
end;
Take care, to close the ref-cursor!
Devs,
I've searched everywhere I can, but I could not find solution to this simple problem.
Situation:
I need to write a procedure where it takes a column name as the input and return all the distinct values present in that column as output. And then I have to use this procedure in some c# code.
In MS server, it is very easy as it will directly give the set of results unlike in PL/SQL.
Script I could write (which is not giving me the result I need):
CREATE OR REPLACE
PROCEDURE GetCol(PARAM IN STRING, recordset OUT sys_refcursor)
AS
BEGIN
OPEN recordset FOR
SELECT DISTINCT(PARAM)
FROM my_table;
END
;
When I try to check the data in the recordset using this code:
DECLARE
l_cursor SYS_REFCURSOR;
l_sname VARCHAR2(50);
BEGIN
GetCol('col_name',l_cursor);
LOOP
FETCH l_cursor INTO l_sname;
EXIT WHEN l_cursor%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(l_sname);
END LOOP;
CLOSE
Can someone help me with this code please.
You can also open a ref_cursor for a string value. Please take a look at this:
CREATE OR REPLACE PROCEDURE GetCol(PARAM IN VARCHAR2, recordset OUT sys_refcursor)
AS
QRY varchar2(100);
BEGIN
QRY := 'SELECT DISTINCT '||PARAM||' FROM my_table';
OPEN recordset FOR QRY;
END;
Then:
DECLARE
l_cursor SYS_REFCURSOR;
l_sname VARCHAR2(50);
BEGIN
GetCol('col_name',l_cursor);
LOOP
FETCH l_cursor INTO l_sname;
EXIT WHEN l_cursor%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(l_sname);
END LOOP;
END;
Your problem is caused by ambiguity about what PARAM is in the procedure's SELECT statement:
CREATE OR REPLACE
PROCEDURE GetCol(PARAM IN STRING, recordset OUT sys_refcursor)
AS
BEGIN
OPEN recordset FOR
SELECT DISTINCT(PARAM) -- Ambiguity here
FROM my_table;
END;
Does PARAM refer to the table column or to the first parameter of the procedure? Oracle has assumed the parameter. You can explicitly say which like this:
SELECT DISTINCT(my_table.PARAM)
FROM my_table;
You could if appropriate (it probably isn't here) specify the procedure parameter instead:
SELECT DISTINCT(GetCol.PARAM)
FROM my_table;
Generally this is best avoided by:
always using table aliases in column references select statements, and
having a standard for parameter names that makes them less likely to clash e.g. P_PARAM.
I have a stored procedure which returns a ref cursor as follows:
CREATE OR REPLACE PROCEDURE AIRS.GET_LAB_REPORT (ReportCurTyp OUT sys_refcursor)
AS
v_report_cursor sys_refcursor;
report_record v_lab_report%ROWTYPE;
l_sql VARCHAR2 (2000);
BEGIN
l_sql := 'SELECT * FROM V_LAB_REPORT';
OPEN v_report_cursor FOR l_sql;
LOOP
FETCH v_report_cursor INTO report_record;
EXIT WHEN v_report_cursor%NOTFOUND;
END LOOP;
CLOSE v_report_cursor;
END;
I want to use the output from this stored procedure in another select statement like:
SELECT * FROM GET_LAB_REPORT()
but I can't seem to get my head around the syntax.
Any ideas?
Whenever I've had to do this; I've used the Oracle TYPE and CAST features.
Something like:
SELECT *
FROM TABLE(CAST(F$get_Cassette_Tracking('8029241') AS cass_tracking_tab_type))
You need to setup the TYPE and all the columns you need and have them use:
pipe ROW(out_obj)
to capture your data. There are many ways to do this and if I can dig out a better example I will but this might give you an idea.
See this SO for a working example: Oracle Parameters with IN statement?