There is a table contains this kind of data: select to_char(sysdate,'day') from dual in a column. I want to get results of the every query that the table keeps.
My result set should be the result of select to_char(sysdate,'day') from dual query. So in this case it is a tuesday.
SO_SQL_BODY is Varchar2.
I wrote this code but it returns only table data.
CREATE or replace PROCEDURE a_proc
AS
CURSOR var_cur IS
select SO_SQL_BODY FROM SO_SUB_VARS group by SO_SQL_BODY;
var_t var_cur%ROWTYPE;
TYPE var_ntt IS TABLE OF var_t%TYPE;
var_names var_ntt;
BEGIN
OPEN var_cur;
FETCH var_cur BULK COLLECT INTO var_names;
CLOSE var_cur;
FOR indx IN 1..var_names.COUNT LOOP
DBMS_OUTPUT.PUT_LINE(var_names(indx).SO_SQL_BODY);
END LOOP;
END a_proc;
DECLARE
res varchar2(4000);
sql_str varchar2(1000);
BEGIN
FOR r IN
(select SO_SQL_BODY FROM SO_SUB_VARS WHERE SO_SQL_BODY IS NOT NULL
)
LOOP
sql_str := r.SO_SQL_BODY;
EXECUTE immediate sql_str INTO res;
dbms_output.put_line(sql_str);
dbms_output.put_line('***********************');
dbms_output.put_line(res);
dbms_output.put_line('***********************');
END LOOP;
END;
/
Try this - iterate to not null records - execute them and print the result.This script works supposing the fact that SO_SQL_BODY contains a query which projects only one column.Also if the projection is with more than two columns then try to use a refcursor and dbms_sql package
İf var_names(indx).SO_SQL_BODY output is a runnable sql text;
CREATE or replace PROCEDURE a_proc
AS
CURSOR var_cur IS
select SO_SQL_BODY FROM SO_SUB_VARS group by SO_SQL_BODY;
var_t var_cur%ROWTYPE;
TYPE var_ntt IS TABLE OF var_t%TYPE;
var_names var_ntt;
BEGIN
OPEN var_cur;
FETCH var_cur BULK COLLECT INTO var_names;
CLOSE var_cur;
FOR indx IN 1..var_names.COUNT LOOP
DBMS_OUTPUT.PUT_LINE(var_names(indx).SO_SQL_BODY);
EXECUTE IMMEDIATE var_names(indx).SO_SQL_BODY;
END LOOP;
END a_proc;
You don't need a full cursor for this example. An implicit one would make it a lot shorter.
create or replace procedure a_proc is
lReturnValue varchar2(250);
begin
for q in (select so_sql_body from so_sub_vars group by so_sql_body)
loop
execute immediate q.so_sql_body into lReturnValue;
dbms_output.put_line(lReturnValue);
end loop;
end a_proc;
You should add an exception handler that will care for cases where there is a bad SQL query in your table. Also note that executing querys saved in a database table is your entry point to SQL injection.
Related
I have a table TestTable with columns of col_test1, col_test2, col_test3 ...
and I want to create a loop that accesses each of these columns individually and find the max value and place it in the variable made in the declare block and simply dbms.out.put it.
Declare
my_array sys.dbms_debug_vc2coll := sys.dbms_debug_vc2coll('col_test1','col_test2','col_test2');
v_test number(8,0);
Begin
for r in my_array.first..my_array.last
loop
select max(my_array(r)) into v_test from TestTable;
dbms_output.put_line(v_test);
end loop;
End;
/
The output I get is just the string 'col_test1'which should be 50.
This is done through oracle SQL. Is there any way to achieve this?
You could use dynamic SQL for this
Declare
my_array sys.dbms_debug_vc2coll := sys.dbms_debug_vc2coll('col_test1','col_test2','col_test2');
v_test number(8,0);
Begin
for r in my_array.first..my_array.last
loop
execute immediate 'select max(' || my_array(r) || ') from TestTable'
into v_test;
dbms_output.put_line(v_test);
end loop;
End;
If you're going to resort to dynamic SQL, however, it would generally make more sense to build a single SQL statement that took that max of all three columns in one pass rather than potentially doing three separate table scans on the same table.
I'm pretty new to Oracle and Database.
I'm trying to write a stored procedure with cursors. How do I write a select statement inside the cursor loop, and how do I loop through the result set that I get from the select inside that cursor loop?
For example:
Open Curs1;
Exit When Curs1%NotFound;
Loop
Select column1,column2 from table -- Returns multiple records. How to loop through this record set and perform CRUD operations.
End loop;
Close Curs1;
Use a FOR-loop cursor - they are faster and simpler than the open/fetch/close syntax.
begin
for results1 in
(
select ...
) loop
--Do something here
for results2 in
(
select ...
where some_table.some_column = results1.some_column
) loop
--Do something here
end loop;
end loop;
end;
/
Although this literally answers the question, you generally do not want to have loops inside loops like this. If possible, it would be better to combine the two SQL statements with a join and then loop through the results.
Try to use the following example that fetches rows one at a time from the cursor variable emp_cv into the user-defined record emp_rec:
declare
TYPE YourType IS ref cursor return YourTable%rowtype;
tab_cv YourType;
tab_rec YourTable%rowtype;
begin
loop
fetch tab_cv into emp_rec;
exit when tab_cv%notfound;
...
end loop;
end;
The BULK COLLECT clause lets you fetch entire columns from the result set, or the entire result set at once. The following example, retrieves columns from a cursor into a collection:
declare
type NameList IS table of emp.ename%type;
names NameList;
cursor c1 is select ename from emp where job = 'CLERK';
begin
open c1;
fetch c1 bulk collect into names;
...
close c1;
end;
The following example uses the LIMIT clause. With each iteration of the loop, the FETCH statement fetches 100 rows (or less) into index-by table acct_ids. The previous values are overwritten.
declare
type NumList is table of number index by binary_integer;
cursor c1 is select acct_id from accounts;
acct_ids NumList;
rows natural := 100; -- set limit
begin
open c1;
loop
/* The following statement fetches 100 rows (or less). */
fetch c1 bulk collect into acct_ids limit rows;
exit when c1%notfound;
...
end loop;
close c1;
end;
You need to declare the CURSOR and FETCH the records in the loop.
DECLARE
CURSOR curs1
IS
SELECT column1,
column2
FROM yourtable;
v_column1 yourtable.column1%TYPE;
v_column2 yourtable.column2%TYPE;
BEGIN
OPEN curs1;
LOOP
FETCH curs1
INTO v_column1,
v_column2;
EXIT
WHEN curs1%NOTFOUND;
INSERT INTO yourtable2(col1)VALUES( '000'||v_column1 );
-- A sample DML operation.
--Do other operations on individual records here.
END LOOP;
CLOSE curs1;
END;
I am building a procedure, where I`m first creating a select statement and store it in an VARCAHR variable.
I now want to execute that query and store the whole result set in an variable to loop through it or use directly in a for loop.
I only find examples where the Select is hard written in the for loop definition.
How do i exchange the Select statement with my variable that holds my select statement?
for r IN (SELECT ... FROM ...)
loop
--do sth;
end loop;
how i want to use it :
statement := 'SELECT .... FROM ...';
for r IN (statement) -- HOW TO DO THIS
loop
--do sth;
end loop;
For a dynamic ref cursor, you need to define everything explicitly:
declare
sqlstring long := 'select 123 as id, ''demo'' as somevalue from dual where dummy = :b1';
resultset sys_refcursor;
type demo_rectype is record
( id integer
, somevalue varchar2(30) );
demorec demo_rectype;
begin
open resultset for sqlstring using 'X';
loop
fetch resultset into demorec;
exit when resultset%notfound;
dbms_output.put_line('id=' || demorec.id || ' somevalue=' || demorec.somevalue);
end loop;
close resultset;
end;
You can parse the cursor and figure out the column names and datatypes with DBMS_SQL. Example here: www.williamrobertson.net/documents/refcursor-to-csv.shtml
I have some problem with dynamic SQL.
I created table, after that inserted some data - it works fine.
But i have no idea how to display data. My code:
declare
begin
execute immediate 'create table name(tabl_name varchar2(30),id number)';
execute immediate 'insert into name(tabl_name,id) (select ''something'',id from table3)';
commit;
and now i would like to display name table content. How to do that? Should i use cursor with dynamic sql? Thanks in advance.
You can use cursor to loop through the records:
declare
v_tabl_name varchar2(30);
v_id number;
res_cur SYS_REFCURSOR;
begin
execute immediate 'create table name(tabl_name varchar2(30),id number)';
execute immediate 'insert into name(tabl_name,id) (select ''something'',id from table3)';
open res_cur for 'select tabl_name, id from name';
LOOP
FETCH res_cur INTO v_tabl_name, v_id;
EXIT WHEN res_cur%NOTFOUND;
dbms_output.put_line(v_tabl_name);
dbms_output.put_line(v_id);
END LOOP;
close res_cur;
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;