I've found a good question at https://dba.stackexchange.com/questions/3587/oracle-automate-export-unload-of-data. Is it valid to use such a construction:
FOR r IN (SELECT * FROM table) LOOP
UTL_FILE.PUT_LINE(lfFilelog, r.row);
END LOOP;
I'm trying to use something like this:
CREATE OR REPLACE PROCEDURE p_name(DESTFOLDER in varchar2, FILENAME in varchar2)
IS
V_FILEHANDLE UTL_FILE.FILE_TYPE;
CURSOR dataset IS
SELECT
field1,
field2,
fieldN
FROM
table1,
table2,
(SELECT field3 from table3);
-- WHERE CLAUSE ... and so on..
BEGIN
V_FILEHANDLE := UTL_FILE.FOPEN(DESTFOLDER, FILENAME, 'w');
FOR R IN dataset LOOP
UTL_FILE.PUT_LINE(V_FILEHANDLE, R.ROW);
END LOOP;
END;
/
and getting pls-00302 error which states that I should have defined ROW component. So as far as I undrestand this field should already exist in the query. Am I right?
Can I simply write a row from the cursor?
The answer mentionned is not complete, I think it was given as an example (pseudo-code) that lacks implementation details.
As it is:
your SELECT clause is invalid, you aren't selecting anything. What do you want to select?
the construct XX.row where xx is a cursor doesn't exist
furthermore, the UTL_FILE.get_line procedure accepts a VARCHAR2 as its second argument, not any kind of rowtype
you can't name a table table (although you could name it "table").
Given a table mytable(col1, col2, ... , colN) you could write:
CREATE OR REPLACE PROCEDURE p_name()
IS
V_FILEHANDLE UTL_FILE.FILE_TYPE;
CURSOR dataset IS SELECT col1, col2, /*...*/ coln FROM mytable;
BEGIN
/*utl_file.fopen maybe?*/
FOR R IN dataset LOOP
UTL_FILE.PUT_LINE(V_FILEHANDLE, R.col1 ||';'|| r.col2 /*...*/ || r.coln);
END LOOP;
END;
Related
declare
vquery long;
cursor c1 is
select * from temp_name;
begin
for i in c1
loop
vquery :='INSERT INTO ot.temp_new(id)
select '''||i.id||''' from ot.customers';
dbms_output.put_line(i.id);
end loop;
end;
/
Output of select * from temp_name is :
ID
--------------------------------------------------------------------------------
customer_id
1 row selected.
I have customers table which has customer_id column.I want to insert all the customer_id into temp_new table but it is not being inserted. The PLSQL block executes successfully but the temp_new table is empty.
The output of dbms_output.put_line(i.id); is
customer_id
What is wrong there?
The main problem is that you generate a dynamic statement that you never execute; at some point you need to do:
execute immediate vquery;
But there are other problems. If you output the generated vquery string you'll see it contains:
INSERT INTO ot.temp_new(id)
select 'customer_id' from ot.customers
which means that for every row in customers you'll get one row in temp_new with ID set to the same fixed literal 'customer_id'. It's unlikely that's what you want; if customer_id is a column name from customers then it shouldn't be in single quotes.
As #mathguy suggested, long is not a sensible data type to use; you could use a CLOB but only really need a varchar2 here. So something more like this, where I've also switched to use an implicit cursor:
declare
l_stmt varchar2(4000);
begin
for i in (select id from temp_name)
loop
l_stmt := 'INSERT INTO temp_new(id) select '||i.id||' from customers';
dbms_output.put_line(i.id);
dbms_output.put_line(l_stmt);
execute immediate l_stmt;
end loop;
end;
/
db<>fiddle
The loop doesn't really make sense though; if your temp_name table had multiple rows with different column names, you'd try to insert the corresponding values from those columns in the customers table into multiple rows in temp_new, all in the same id column, as shown in this db<>fiddle.
I guess this is the starting point for something more complicated, but still seems a little odd.
Apologies for the newbie question, I am writing an Oracle stored procedure that opens a cursor for a specific SQL, calculates some variables for each row returned by the cursor but the stored procedure should return as a result set these variables that have been calculated for each row returned by the cursor. I am a bit confused on how to do this - can anyone help?!
I did read some of it so far I have something like this (just a trimmed down example and not exact code) but just need to return v_calc and v_calc_res in a result set:-
CREATE OR REPLACE procedure sp_test
(
in_input in number,
out_return out sys_refcursor
)
as
v_calc number;
v_calc_res number;
CURSOR C_test IS
select blah from test where blah = in_input;
begin
open c_test
loop
fetch c_test into v_calc;
v_calc_res := v_calc*5;
end loop;
end;
If you want a procedure to return a reference cursor for the calling routine to consume the procedure itself cannot then consume it. Cursors, including reference cursors are 1 way, 1 time consumables. As for as the desired calculations, they can be added to select defined for the cursor. So:
-- setup
create table test (blah integer, blah_stuff varchar2(50) );
-- build sp
create or replace procedure sp_blah_text(
in_input in number
, out_cur out sys_refcursor
)
is
begin
open out_cur for
select blah, blah_stuff, blah*5 as blah_x_5
from test
where blah = in_input;
end sp_blah_text;
-- test data
insert into test(blah, blah_stuff)
select 1,'a' from dual union all
select 2,'b' from dual union all
select 2,'x' from dual union all
select 2,'z' from dual union all
select 3,'c' from dual;
-- test
declare
ref_cur sys_refcursor;
l_blah test.blah%type;
l_stuff test.blah_stuff%type;
l_blah_5 test.blah%type;
begin
dbms_output.enable(null);
sp_blah_text(2,ref_cur);
loop
fetch ref_cur
into l_blah
, l_stuff
, l_blah_5;
exit when ref_cur%notfound;
dbms_output.put_line('blah=' || l_blah || ',stuff=' || l_stuff || ',blah*5=' || l_blah_5);
end loop;
end;
This works a treat thank you very much. I now have a performance issue that maybe you could help with. When I open the cursor, I then run several other SELECT statements to retrieve values using the variables from the cursor (see below). I assume this is because the switch between PL/SQL and SQL engine. Would using table collections help? But as I see since I need different columns from different tables I would need to have several different collections, how could I output everything in one record?
CREATE OR REPLACE procedure sp_test
(
in_input in number
)
as
v_calc number;
v_calc_res number;
v_blah_blah number;
v_blah_blah_blah number;
v_blah_blah_blah number;
CURSOR C_test IS
select blah from test where blah = in_input;
begin
open c_test
loop
fetch c_test into v_calc;
select blah_blah into v_blah_blah from t_blah_blah;
select blah_blah_blah into v_blah_blah_blah from t_blah_blah_blah;
select blah_blah_blah_blah into v_blah_blah_blah_blah from t_blah_blah_blah_blah;
v_calc_res := v_calc*5*v_blah_blah*v_blah_blah_blah*v_blah_blah_blah_blah
end loop;
end;
not sure if this is possible at all but im trying to do this with as little manual work as possible.
I have a table with 150 columns based on different combinations of factors.
I wish to extract the column names where a certain certain string is inside the column name.
I have done the following which does this. This is a basic example of what I have
--Create the table
Create Table temp
(id number,
Fac1_Fac2_Fac_3_Fac4_Fac5 number,
Fac1_Fac6_Fac_3_Fac4_Fac5 number,
Fac1_Fac6_Fac_7_Fac4_Fac5 number,
Fac1_Fac9_Fac_3_Fac4_Fac5 number,
Fac1_Fac10_Fac_3_Fac4_Fac5 number,
Fac1_Fac2_Fac_3_Fac11_Fac5 number,
Fac1_Fac2_Fac_3_Fac4_Fac12 number,
Fac13_Fac2_Fac_3_Fac4_Fac5 number);
Insert into temp Values (1,35634,3243,343,564,56,4635,3,334);
Insert into temp Values (2,3434234,3243,343,564,56,435,3,34234);
Insert into temp Values (3,5555,3243,33,564,56,435,3,3434);
Insert into temp Values (4,34234,343,343,564,56,4335,3,34);
commit;
--Extract Column Names
Select * from (
Select COLUMN_NAME
from user_tab_cols
where lower(table_name) ='temp'
)
where column_name like '%FAC13%'
--This is what I want to automate.
Select id, FAC13_FAC2_FAC_3_FAC4_FAC5
From temp
--I want the column name to come fron the select statment above as there may be lots of names.
Basically, I want to select all the rows from my table that have Fac13 in the column name all in one query if possible.
Thanks
I do not think you can do that in one query. First, your extract column names query can be simplified to one query as a cursor, and then use a dynamic select statement as follows:
CREATE OR REPLACE proc_dyn_select IS
CURSOR c1 IS
SELECT column_name
FROM user_tab_cols
WHERE LOWER(table_name) ='temp' and column_name LIKE '%FAC13%';
cols c1%ROWTYPE;
sqlstmt VARCHAR2(2000);
BEGIN
OPEN c1;
LOOP
FETCH c1 into cols;
EXIT WHEN c1%NOTFOUND;
sqlstmt := sqlstmt ||cols.column_name||',';
END LOOP;
CLOSE c1;
sqlstmt := 'select '||substr(sqlstmt, 1, length(sqlstmt)-1)||' FROM temp';
EXECUTE IMMEDIATE sqlstmt;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('error '||sqlerrm);
END;
/
Explanation
First, the cursor will store the columns that meet your conditions (to be from the table temp and the column names have the sub string FAC13. Then in execution section (after BEGIN), you will build your query dynamically using columns names stored in the cursor c1. With each round of the loop, a column name is added as a string and concatenated with a comma. So a string of columns will be built like this 'col1, col2, col3, ... coln,'. The string is stored in sqlstmt variable.
After the loop end, you amend the string to build sql statement, by adding the keywords SELECT, FROM and table name. However, we remove the last character of the sqlstmt variable, as it is an extra comma.
EXECUTE IMMEDIATE statement, will run the query stored in sqlstmt.
By using a procedure, you can always pass parameters, such that this procedure can perform any dynamic sql statement you want.
I have to generate a table (contains two columns) of random data from a database table through oracle procedure. The user can indicate the number of data required and we have to use the table data with ID values from 1001 to 1060. I am trying to use cursor loop and not sure dbms_random method dhould I use.
I am using the following code to create procedure
create or replace procedure a05_random_plant(p_count in number)
as
v_count number := p_count;
cursor c is
select plant_id, common_name
from ppl_plants
where rownum = v_count
order by dbms_random.value;
begin
delete from a05_random_plants_table;
for c_table in c
loop
insert into a05_random_plants_table(plant_id, plant_name)
values (c_table.plant_id, c_table.common_name);
end loop;
end;
/
it complied successfully. Then I executed with the following code
set serveroutput on
exec a05_random_plant(5);
it shows anonymous block completed
but when run the following code, I do not get any records
select * from a05_random_plants_table;
The rownum=value would not work for a value greater than 1
hence try the below
create or replace procedure a05_random_plant(p_count in number)
as
v_count number := p_count;
cursor c is
select plant_id, common_name
from ppl_plants
where rownum <= v_count
order by dbms_random.value;
begin
delete from a05_random_plants_table;
for c_table in c
loop
insert into a05_random_plants_table(plant_id, plant_name)
values (c_table.plant_id, c_table.common_name);
end loop;
end;
/
Query by Tom Kyte - will generate almost 75K of rows:
select trunc(sysdate,'year')+mod(rownum,365) TRANS_DATE,
mod(rownum,100) CUST_ID,
abs(dbms_random.random)/100 SALES_AMOUNT
from all_objects
/
You can use this example to write your query and add where clause to it - where id between 1001 and 1060, for example.
I don't think you should use a cursor (which is slow naturally) but do a direct insert from a select:
insert into table (col1, col2)
select colx, coly from other_table...
And, isn't missing a COMMIT on the end of your procedure?
So, all code in your procedure would be a DELETE, a INSERT WITH that SELECT and then a COMMIT.
I am following these steps, but I continue to get an error and don't see the issue:
1) Create a custom Oracle datatype that represents the database columns that you want to retrieve:
CREATE TYPE my_object AS OBJECT
(COL1 VARCHAR2(50),
COL2 VARCHAR2(50),
COL3 VARCHAR2(50));
2) Create another datatype that is a table of the object you just created:
TYPE MY_OBJ_TABLE AS TABLE OF my_object;
3) Create a function that returns this table. Also use a pipeline clause so that results are pipelined back to the calling SQL, for example:
CREATE OR REPLACE
FUNCTION MY_FUNC (PXOBJCLASS varchar2)
RETURN MY_OBJ_TABLE pipelined IS
TYPE ref1 IS REF CURSOR
Cur1 ref1,
out_rec_my_object := my_object(null,null,null);
myObjClass VARCHAR2(50);
BEGIN
myObjClass := PXOBJCLASS
OPEN Cur1 For ‘select PYID, PXINSNAME, PZINSKEY from PC_WORK where PXOBJCLass = ;1’USING myObjClass,
LOOP
FETCH cur1 INTO out_rec.COL1, out_rec.COL2, out_rec.COL3;
EXIT WHEN Cur1%NOTFOUND;
PIPE ROW (out_rec);
END LOOP;
CLOSE Cur1;
RETURN;
END MY_FUNC;
NOTE: In the example above, you can easily replace the select statement with a call to another stored procedure that returns a cursor variable.
4) In your application, call this function as a table function using the following SQL statement:
select COL1, COL2, COL3 from TABLE(MY_FUNC('SomeSampletask'));
There is no need to use dynamic sql (dynamic sql is always a little bit slower) and there are too many variables declared. Also the for loop is much easier. I renamed the argument of the function from pxobjclass to p_pxobjclass.
Try this:
create or replace function my_func (p_pxobjclass in varchar2)
return my_obj_table pipelined
is
begin
for r_curl in (select pyid,pxinsname,pzinskey
from pc_work
where pxobjclass = p_pxobjclass) loop
pipe row (my_object(r_curl.pyid,r_curl.pxinsname,r_curl.pzinskey));
end loop;
return;
end;
EDIT1:
It is by the way faster to return a ref cursor instead of a pipelined function that returns a nested table:
create or replace function my_func2 (p_pxobjclass in varchar2)
return sys_refcursor
is
l_sys_refcursor sys_refcursor;
begin
open l_sys_refcursor for
select pyid,pxinsname,pzinskey
from pc_work
where pxobjclass = p_pxobjclass;
return l_sys_refcursor;
end;
This is faster because creating objects (my_object) takes some time.
I see two problems:
The dynamic query does not work that way, try this:
'select PYID, PXINSNAME, PZINSKEY from PC_WORK where PXOBJCLass ='''||PXOBJCLASS||''''
You don't need myObjClass, and it seems all your quotes are wrong.
The quoting on 'SomeSampletask'...
select COL1, COL2, COL3 from TABLE(MY_FUNC('SomeSampletask'));
Maybe I'm misunderstanding something here, but it seems like you want to be using a VIEW.