I've created one table "Meta_Data_Table_Names" where I inserted forty eight table names in the MetaTableName column. And there is another column to provide Row count with corresponding table name.
I wanted to fetch the table name from “Meta_Data_Table_Names” and execute SELECT Query sequentially through Loop for validation purpose.
Whenever, I execute from TOAD , It’s throwing an error:
Table or view does not exist.
Do we need to make a place holder for 'Meta_name' which can be scanned? Or any particular syntax to read the value during Query?
DECLARE
CURSOR c1 IS SELECT MetaTableName FROM Meta_Data_Table_Names;
CURSOR c2 IS SELECT ROW_COUNT FROM Meta_Data_Table_Names;
Meta_name Meta_Data_Table_Names.MetaTableName%TYPE;
Count_num Meta_Data_Table_Names.ROW_COUNT%TYPE;
BEGIN
OPEN c1;
OPEN c2;
FOR i IN 1..48 LOOP
FETCH c1 INTO Meta_name;
FETCH c2 INTO Count_num;
IF (Count_num > 2000)
THEN
SELECT * FROM Meta_Name X
MINUS
SELECT * from ASFNCWK07.Meta_Name#NCDV.US.ORACLE.COM Y
UNION ALL
SELECT * FROM ASFNCWK07.Meta_Name#NCDV.US.ORACLE.COM Y
MINUS
SELECT * FROM Meta_Name X;
ELSE
DBMS_OUTPUT.PUT_LINE ('No Validation is required');
END IF;
END LOOP;
END;
Oracle does not allow you to do queries with dynamic table names, i.e. if the table name is not known at compile time. Do do that, you need Dynamic SQL, which is a bit too broad to go into here.
There are a number of problems with your code.
Firstly, we cannot use variable names in normal SQL: for this we need dynamic SQL. For instance:
execute immediate 'select 1 from '|| Meta_Name || into n;
There are a lot of subtleties when working with dynamic SQL: the PL/SQL documentation devotes a whole chapter to it. Find out more.
Secondly, when executing SQL in PL/SQL, we need need to provide a target variable. This must match the projection of the executed query. When selecting a whole row the %ROWTYPE keyword is useful. Again the documentation covers this: find out more. Which leads to ...
Thirdly, because you're working with dynamic SQL and you don't know in advance which tables will be in scope, you can't easily declare target variables. This means you'll need to use ref cursors and/or Type 4 dynamic SQL techniques. Yikes! Read Adrian Billington's excellent blog article here.
Lastly (I think), the UNION ALL in your query doesn't allow you to identify which rows are missing from where. Perhaps that doesn't matter.
Related
Code:
lc_tab1_col1 VARCHAR2(4000);
lc_tab1_col2 VARCHAR2(4000);
lc_tab2_col2 VARCHAR2(4000);
lc_tab2_col2 VARCHAR2(4000);
CURSOR my_cursor IS select col1, col2 from tab1;
[...]
OPEN my_cursor;
LOOP
FETCH my_cursor INTO lc_tab1_col1, lc_tab1_col2;
EXIT WHEN my_cursor%NOTFOUND;
SELECT lc_tab1_col2.col1, lc_tab1_col2.col2 INTO lc_tab2_col2, lc_tab2_col2 FROM lc_tab1_col2 WHERE lc_tab1_col2.col3 = lc_tab1_col1;
[...]
END LOOP;
CLOSE my_cursor;
Hey folks,
I am trying to get the above code working.
The issue I am having is that a SELECT INTO statement apparently does not support using a variable (in that case lc_tab1_col2) as the table name in the FROM clause of the statement.
When compiling the package an ORA-000942 is thrown (table or view does not exist), which tells me the variable is interpreted directly instead of being replaced and interpreted at runtime.
I can't think of a workaround on the fly, any ideas on how to fix this?
Some more background: lc_tab1_col2 contains the name of a table in the database whereas lc_tab1_col1 contains an ID.
This ID is present in all of the tables that can be contained in lc_tab1_col2 (hence the WHERE clause).
Apart from the ID there are two other columns (lc_tab1_col2.col1 and lc_tab1_col2.col2) that are present in all those tables, but that are not present in tab1. I need to select those two values to work with them inside the loop.
As there are many tables to consider, I need this SELECT INTO statement to be dynamic. It wouldn't be feasible to parse the tables one by one. Looking forward to anyone sharing a clever idea for overcoming this issue :) Thanks in advance!
I think, you exception really means that this table does not exist or you don't have privileges to SELECT it.
I've executed a below code and everything was ok. I have tried to compile it in a package and also I didn't have any compilation errors
DECLARE
user_tables varchar2(30) := 'TBLCOMPANIES';
BEGIN
SELECT table_name
INTO user_tables
FROM user_tables
WHERE user_tables.table_name = user_tables;
dbms_output.put_line(user_tables) ;
END;
/
I'm currently learning SQL and I'm having trouble with a procedure of mine. The procedure should calculate the average of a column called 'INDICE_METABO_PAT'. The information I need is in 3-4 different tables. Then when I do have the average calculated, I update a table to set this average to the corresponding entries. Here is the procedure. Note that everything else in my .sql file works : inserts, updates, selects, views, etc.
create or replace Procedure SP_UPDATE_INDICE_METABO_DV (P_NO_ETUDE in number)
is
V_SOMME number := 0;
V_NBPATIENT number := 0;
V_NO_ETUDE number := P_NO_ETUDE;
cursor curseur is
select PATIENT.INDICE_EFFICACITE_METABO_PAT
from ETUDE, DROGUE_VARIANT, ETUDE_PATIENT, PATIENT
where ETUDE.NO_DROGUE = DROGUE_VARIANT.NO_DROGUE
and ETUDE.NO_VAR_GEN = DROGUE_VARIANT.NO_VAR_GEN
and V_NO_ETUDE = ETUDE_PATIENT.NO_ETUDE
and ETUDE_PATIENT.NO_PATIENT = PATIENT.NO_PATIENT;
begin
open curseur;
fetch curseur into V_SOMME;
V_NBPATIENT := V_NBPATIENT + 1;
exit when curseur%NOTFOUND;
update DROGUE_VARIANT
set INDICE_EFFICACITE_METABO_DV = V_SOMME / V_NBPATIENT
where exists(select * from ETUDE, DROGUE_VARIANT, ETUDE_PATIENT, PATIENT
where ETUDE.NO_DROGUE = DROGUE_VARIANT.NO_DROGUE
and ETUDE.NO_VAR_GEN = DROGUE_VARIANT.NO_VAR_GEN
and V_NO_ETUDE = ETUDE_PATIENT.NO_ETUDE
and ETUDE_PATIENT.NO_PATIENT = PATIENT.NO_PATIENT);
end SP_UPDATE_INDICE_METABO_DV;
/
I'm getting an error : Procedure compiled , error check compiler log.
But I can't open the compiler log, and when my friend opens it, it points to weird places, like my create tables and such.
This is school stuff by the way, so it'll be nice if you could give an insight instead of a direct solution. Thanks alot.
Thanks alot in advance for your kind help !
To see the error you can do show errors after your procedure creation statement, or you can query the user_errors or all_errors views.
That will show something like:
LINE/COL ERROR
-------- ------------------------------------------------------------------------
20/4 PLS-00376: illegal EXIT/CONTINUE statement; it must appear inside a loop
20/4 PL/SQL: Statement ignored
You mentioned that when you checked the complier log, which shows the same information, "it points to weird places". Presumably you're looking at line 20 in your script. But this message is referring to line 20 of the PL/SQL code block, which is the exit when curseur%NOTFOUND;, which makes sense for the error message.
And as the message also says, and as #ammoQ said in a comment, that should be in a loop. If you're trying to manually calculate the average in a procedure as an exercise, instead of using the built-in aggregation functions, then you need to loop over all of the rows from your cursor:
open curseur;
loop
fetch curseur into V_SOMME;
exit when curseur%NOTFOUND;
V_NBPATIENT := V_NBPATIENT + 1;
end loop;
close curseur;
But as you'll quickly realise, you'll end up with the v_somme variable having the last value retrieved, not the sum of all the values. You need a separate variable keep to track of the sum - fetch each value into a variable, and add that to your running total, all within the loop. But as requested, not giving a complete solution.
As you're starting out you should really use ANSI join syntax, not the old from/where syntax you have now. It's a shame that is still being taught. So your cursor query should be something like:
select PATIENT.INDICE_EFFICACITE_METABO_PAT
from ETUDE_PATIENT
join ETUDE
-- missing on clause !
join DROGUE_VARIANT
on DROGUE_VARIANT.NO_DROGUE = ETUDE.NO_DROGUE
and DROGUE_VARIANT.NO_VAR_GEN = ETUDE.NO_VAR_GEN
join PATIENT
on PATIENT.NO_PATIENT = ETUDE_PATIENT.NO_PATIENT
where ETUDE_PATIENT.NO_ETUDE = P_NO_ETUDE;
... which shows you that you are missing a join condition between ETUDE_PATIENT and ETUDE - it's unlikely you want a cartesian product, and it's much easier to spot that missing join using this syntax than with what you had.
You need to look at your update statement carefully too, particularly the exists clause. That will basically always return true if the cursor found anything, so it will update every row in DROGUE_VARIANT with your calculated average, which presumably isn't what you want.
There is no correlation between the rows in the table you're updating and the subquery in that clause - the DROGUE_VARIANT in the subquery is independent of the DROGUE_VARIANT you're updating. By which I mean, it's the same table, obviously; but the update and the subquery are looking at the table separately and so are looking at different rows. It also has the same missing join condition as the cursor query.
I have 2 procedures inside a package. I am calling one procedure to get a comma separated list of user ids.
I am storing the result in a VARCHAR variable. Now when I am using this comma separated list to put inside an IN clause in it is throwing "ORA-01722:INVALID NUMBER" exception.
This is how my variable looks like
l_userIds VARCHAR2(4000) := null;
This is where i am assigning the value
l_userIds := getUserIds(deptId); -- this returns a comma separated list
And my second query is like -
select * from users_Table where user_id in (l_userIds);
If I run this query I get INVALID NUMBER error.
Can someone help here.
Do you really need to return a comma-separated list? It would generally be much better to declare a collection type
CREATE TYPE num_table
AS TABLE OF NUMBER;
Declare a function that returns an instance of this collection
CREATE OR REPLACE FUNCTION get_nums
RETURN num_table
IS
l_nums num_table := num_table();
BEGIN
for i in 1 .. 10
loop
l_nums.extend;
l_nums(i) := i*2;
end loop;
END;
and then use that collection in your query
SELECT *
FROM users_table
WHERE user_id IN (SELECT * FROM TABLE( l_nums ));
It is possible to use dynamic SQL as well (which #Sebas demonstrates). The downside to that, however, is that every call to the procedure will generate a new SQL statement that needs to be parsed again before it is executed. It also puts pressure on the library cache which can cause Oracle to purge lots of other reusable SQL statements which can create lots of other performance problems.
You can search the list using like instead of in:
select *
from users_Table
where ','||l_userIds||',' like '%,'||cast(user_id as varchar2(255))||',%';
This has the virtue of simplicity (no additional functions or dynamic SQL). However, it does preclude the use of indexes on user_id. For a smallish table this shouldn't be a problem.
The problem is that oracle does not interprete the VARCHAR2 string you're passing as a sequence of numbers, it is just a string.
A solution is to make the whole query a string (VARCHAR2) and then execute it so the engine knows he has to translate the content:
DECLARE
TYPE T_UT IS TABLE OF users_Table%ROWTYPE;
aVar T_UT;
BEGIN
EXECUTE IMMEDIATE 'select * from users_Table where user_id in (' || l_userIds || ')' INTO aVar;
...
END;
A more complex but also elegant solution would be to split the string into a table TYPE and use it casted directly into the query. See what Tom thinks about it.
DO NOT USE THIS SOLUTION!
Firstly, I wanted to delete it, but I think, it might be informative for someone to see such a bad solution. Using dynamic SQL like this causes multiple execution plans creation - 1 execution plan per 1 set of data in IN clause, because there is no binding used and for the DB, every query is a different one (SGA gets filled with lots of very similar execution plans, every time the query is run with a different parameter, more memory is needlessly used in SGA).
Wanted to write another answer using Dynamic SQL more properly (with binding variables), but Justin Cave's answer is the best, anyway.
You might also wanna try REF CURSOR (haven't tried that exact code myself, might need some little tweaks):
DECLARE
deptId NUMBER := 2;
l_userIds VARCHAR2(2000) := getUserIds(deptId);
TYPE t_my_ref_cursor IS REF CURSOR;
c_cursor t_my_ref_cursor;
l_row users_Table%ROWTYPE;
l_query VARCHAR2(5000);
BEGIN
l_query := 'SELECT * FROM users_Table WHERE user_id IN ('|| l_userIds ||')';
OPEN c_cursor FOR l_query;
FETCH c_cursor INTO l_row;
WHILE c_cursor%FOUND
LOOP
-- do something with your row
FETCH c_cursor INTO l_row;
END LOOP;
END;
/
I use a cursor for the statement:
SELECT NAME FROM STUDENT WHERE ROLL = 1;
I used:
CURSOR C IS SELECT NAME FROM STUDENT WHERE ROLL = roll;
--roll is a variable I receive via a procedure, and the procedure works fine for the received parameter.
Upon executing this, I am able to retrieve all records with roll = 1.
Now, I need to retrieve the records of a group (possibly via a cursor), just like:
SELECT NAME FROM STUDENT WHERE ROLL IN (2, 4, 6);
But the values in the IN clause are known only at run time. How should I do this? That is, is there any way I could assign parameters to the WHERE clause of the cursor?
I tried using an array in the declaration of the cursor, but an error pops up telling something like: standard types cannot be used.
I used:
CURSOR C IS SELECT NAME FROM STUDENT WHERE ROLL IN (rolls);
--rolls is an array initialized with the required roll numbers.
First, I assume that the parameter to your procedure doesn't actually match the name of a column in the STUDENT table. If you actually coded the statement you posted, roll would be resolved as the name of the column, not the parameter or local variable so this statement would return every row in the STUDENT table where the ROLL column was NOT NULL.
CURSOR C
IS SELECT NAME
FROM STUDENT
WHERE ROLL = roll;
Second, while it is possible to use dynamic SQL as #Gaurav Soni suggests, doing so generates a bunch of non-sharable SQL statements. That's going to flood the shared pool, probably aging other statements out of cache, and use a lot of CPU hard-parsing the statement every time. Oracle is built on the premise that you are going to parse a SQL statement once, generally using bind variables, and then execute the statement many times with different values for the bind variables. Oracle can go through the process of parsing the query, generating the query plan, placing the query in the shared pool, etc. only once and then reuse all that when you execute the query again. If you generate a bunch of SQL statements that will never be used again because you're using dynamic SQL without bind variables, Oracle is going to end up spending a lot of time caching SQL statements that will never be executed again, pushing useful cached statements that will be used again out of the shared pool meaning that you're going to have to re-parse those queries the next time they're encountered.
Additionally, you've opened yourself up to SQL injection attacks. An attacker can exploit the procedure to read any data from any table or execute any function that the owner of the stored procedure has access to. That is going to be a major security hole even if your application isn't particularly security conscious.
You would be better off using a collection. That prevents SQL injection attacks and it generates a single sharable SQL statement so you don't have to do constant hard parses.
SQL> create type empno_tbl is table of number;
2 /
Type created.
SQL> create or replace procedure get_emps( p_empno_arr in empno_tbl )
2 is
3 begin
4 for e in (select *
5 from emp
6 where empno in (select column_value
7 from table( p_empno_arr )))
8 loop
9 dbms_output.put_line( e.ename );
10 end loop;
11 end;
12 /
Procedure created.
SQL> set serveroutput on;
SQL> begin
2 get_emps( empno_tbl( 7369,7499,7934 ));
3 end;
4 /
SMITH
ALLEN
MILLER
PL/SQL procedure successfully completed.
create or replace procedure dynamic_cur(p_empno VARCHAR2) IS
cur sys_refcursor;
v_ename emp.ename%type;
begin
open cur for 'select ename from emp where empno in (' || p_empno || ')';
loop
fetch cur into v_ename;
exit when cur%notfound;
dbms_output.put_line(v_ename);
end loop;
close cur;
end dynamic_cur;
Procedure created
Run the procedure dynamic_cur
declare
v_empno varchar2(200) := '7499,7521,7566';
begin
dynamic_cur(v_empno);
end;
Output
ALLEN
WARD
JONES
Note:As mentioned by XQbert,dynamic cursor leads to SQL injection ,but if you're not working on any critical requirement ,where security is not involved then you can use this .
Maybe you can pass rolls as a set of quoted comma separated values.
e.g. '1', '2' etc
If this value is passes into the procedure in a varchar input variable, the it can be used to get multiple rows as per the table match.
Hence the cursor
SELECT NAME FROM STUDENT WHERE ROLL IN (rolls);
will be evaluated as
SELECT NAME FROM STUDENT WHERE ROLL IN ('1','2');
Hope it helps
I need to run big queries (that was a part of SP) and look at their results (just trying to find a bug in a big SP with many unions. I want to break it into parts and run them separately).
How can I do that if this SP have few parameters? I don't want to replace them in code, it would be great just to add declare in a header with a hardcode for this parameter.
I've tried something like this:
DECLARE
p_asOfDate DATE := '22-Feb-2011';
BEGIN
SELECT * from myTable where dateInTable < p_asOfDate;
END
But it says that I should use INTO keyword. How can I view this results in my IDE? (I'm using Aqua data studio)
I need to do that very often, so will be very happy if will find a simple solution
You are using an anonymous block of pl/sql code.
In pl/sql procedures you need to specify a target variable for the result.
So you first need to define a variable to hold the result in the declare section
and then insert the result data into it.
DECLARE
p_asOfDate DATE := '22-Feb-2011';
p_result myTable%ROWTYPE;
BEGIN
select * into p_result from myTable where dateInTable < p_asOfDate;
END
That said you will probaply get more than one row returned, so I would use
a cursor to get the rows separately.
DECLARE
CURSOR c_cursor (asOfDate IN DATE) is
select * from myTable where dateInTable < asOfDate;
p_asOfDate DATE := '22-Feb-2011';
p_result myTable%ROWTYPE;
BEGIN
OPEN c_cursor(p_asOfDate);
loop
FETCH c_cursor into p_result;
exit when c_cursor%NOTFOUND;
/* do something with the result row here */
end loop;
CLOSE c_cursor;
END
To output the results you can use something like this for example:
dbms_output.put_line('some text' || p_result.someColumn);
Alternatively you can execute the query on an sql command-line (like sqlplus)
and get the result as a table immediately.
I hope I understood your question correctly...
update
Here is a different way to inject your test data:
Use your tools sql execution environemnt to submit your sql statement directly without a pl/sql block.
Use a "&" in front of the variable part to trigger a prompt for the variable.
select * from myTable where dateInTable < &p_asOfDate;
The Result should be displayed in a formatted way by your tool this way.
I do not know about Aqua, but some tools have functions to define those parameters outside the sql code.