i'm with a problem in a query.
I have a table called "store" that I need to query.
Select s.store_name
from store s
where s.store = case
when p_store != 0 then
p_store
else
s.store
end;
This should work but as I have "stores" with characters (-) in column and this is defined as number, that query raise an exception: ORA-01722: invalid number.
So I want to do something like this in query:
IF p_store != 0 then
select store_name from store where store = p_store
else
select store_name from store;
Is it possible?
Thanks!
EDIT:
The query that I wrote above was an example of the query I was running.
The exception was raised because another column (too much hours in front of PC :-( ).
This table have a column that's varchar2(15) and I was doing this condition:
(...)AND S.CODE > 4 (...)
The correct condition that I want to do is:
(...)AND LENGTH(S.CODE) > 4
Thank you all!
As far as I understand you have varchar2 s.store which in fact contains numbers so Oracle tries to compare it casting to numbers but at some point it gets - and throws an exception. What you should do is update on table replacing - by null. But if you don't want to do that you can try to make case return varchar2
Select s.store_name
from store s
where s.store = case
when to_char(p_store) != '0' then
to_char(p_store)
else
s.store
end;
I am guessing you are running the query in a plsql block (as cursor?). In that case dynamic sql is the way to go. check out REF CURSOR too (google!).
Related
I have the following query that I am using in Oracle 11g
IF EXISTS (SELECT * FROM EMPLOYEE_MASTER WHERE EMPID='ABCD32643')
THEN
update EMPLOYEE_MASTER set EMPID='A62352',EMPNAME='JOHN DOE',EMPTYPE='1' where EMPID='ABCD32643' ;
ELSE
insert into EMPLOYEE_MASTER(EMPID,EMPNAME,EMPTYPE) values('A62352','JOHN DOE','1') ;
END IF;
On running the statement I get the following output:
Error starting at line : 4 in command -
ELSE
Error report -
Unknown Command
1 row inserted.
Error starting at line : 6 in command -
END IF
Error report -
Unknown Command
The values get inserted with error when I run it directly. But when I try to execute this query through my application I get an oracle exception because of the error generated :
ORA-00900: invalid SQL statement
And hence the values are not inserted.
I am relatively new to Oracle. Please advise on what's wrong with the above query so that I could run this query error free.
If MERGE doesn't work for you, try the following:
begin
update EMPLOYEE_MASTER set EMPID='A62352',EMPNAME='JOHN DOE',EMPTYPE='1'
where EMPID='ABCD32643' ;
if SQL%ROWCOUNT=0 then
insert into EMPLOYEE_MASTER(EMPID,EMPNAME,EMPTYPE)
values('A62352','JOHN DOE','1') ;
end if;
end;
Here you you the update on spec, then check whether or not you found a matching row, and insert in case you didn't.
"what's wrong with the above query "
What's wrong with the query is that it is not a query (SQL). It should be a program snippet (PL/SQL) but it isn't written as PL/SQL block, framed by BEGIN and END; keywords.
But turning it into an anonymous PL/SQL block won't help. Oracle PL/SQL does not support IF EXISTS (select ... syntax.
Fortunately Oracle SQL does support MERGE statement which does the same thing as your code, with less typing.
merge into EMPLOYEE_MASTER em
using ( select 'A62352' as empid,
'JOHN DOE' as empname,
'1' as emptype
from dual ) q
on (q.empid = em.empid)
when not matched then
insert (EMPID,EMPNAME,EMPTYPE)
values (q.empid, q.empname, q.emptype)
when matched then
update
set em.empname = q.empname, em.emptype = q.emptype
/
Except that you're trying to update empid as well. That's not supported in MERGE. Why would you want to change the primary key?
"Does this query need me to add values to all columns in the table? "
The INSERT can have all the columns in the table. The UPDATE cannot change the columns used in the ON clause (usually the primary key) because that's a limitation of the way MERGE works. I think it's the same key preservation mechanism we see when updating views. Find out more.
I have an oracle error executing this PL/SQL in the second line: SELECT ....
But for God's sake ! I've already check if there is some null values
IF zocRole IS NOT NULL and devices.unit_id IS NOT NULL THEN
SELECT unit_role_id INTO unitRoleId FROM T_UNIT_ROLE WHERE role_id = zocRole AND unit_id = devices.unit_id;
END IF;
As mentioned above, this exception is thrown because your implicit cursor returns no rows. You would also get an exception if more than one row is returned.
You could instead use an Explicit Cursor Oracle Documents This is really just a named SQL statement (into which you can pass parameters if you like).
You then open the cursor, fetch (each fetch will attempt to retrieve one row) and close. You can then check whether the fetch returned any data. It takes slightly longer to code but can look cleaner.
I remember that years ago there was some debate about the relative speed of implicit vs explicit cursors but I've not heard anyone talk about this for a long time so I assume they perform the same
The best way to control the execution in a procedure/function plsql is adding blocks: BEGIN/EXCEPTION.
IF zocRole IS NOT NULL AND devices.unit_id IS NOT NULL
THEN
BEGIN
SELECT unit_role_id
INTO unitRoleId
FROM T_UNIT_ROLE
WHERE role_id = zocRole
AND unit_id = devices.unit_id
;
EXCEPTION
WHEN OTHERS
THEN dbms_output.put_line(SQLCODE||'-'||SUBSTR(SQLERRM, 1, 200));
END
;
END IF
;
I have the following function, which returns the next available client ID from the Client table:
CREATE OR REPLACE FUNCTION getNextClientID RETURN INT AS
ctr INT;
BEGIN
SELECT MAX(NUM) INTO ctr FROM Client;
IF SQL%NOTFOUND THEN
RETURN 1;
ELSIF SQL%FOUND THEN
-- RETURN SQL%ROWCOUNT;
RAISE_APPLICATION_ERROR(-20010, 'ROWS FOUND!');
-- RETURN ctr + 1;
END IF;
END;
But when calling this function,
BEGIN
DBMS_OUTPUT.PUT_LINE(getNextClientID());
END;
I get the following result:
which I found a bit odd, since the Client table contains no data:
Also, if I comment out RAISE_APPLICATION_ERROR(-20010, 'ROWS FOUND!'); & log the value of SQL%ROWCOUNT to the console, I get 1 as a result.
On the other hand, when changing
SELECT MAX(NUM) INTO ctr FROM Client;
to
SELECT NUM INTO ctr FROM Client;
The execution went as expected. What is the reason behind this behavior ?
Aggregate functions will always return a result:
All aggregate functions except COUNT(*), GROUPING, and GROUPING_ID
ignore nulls. You can use the NVL function in the argument to an
aggregate function to substitute a value for a null. COUNT and
REGR_COUNT never return null, but return either a number or zero. For
all the remaining aggregate functions, if the data set contains no
rows, or contains only rows with nulls as arguments to the aggregate
function, then the function returns null.
You can change your query to:
SELECT COALESCE(MAX(num), 1) INTO ctr FROM Client;
and remove the conditionals altogether. Be careful about concurrency issues though if you do not use SELECT FOR UPDATE.
Query with any aggregate function and without GROUP BY clause always returns 1 row. If you want no_data_found exception on empty table, add GROUP BY clause or remove max:
SQL> create table t (id number, client_id number);
Table created.
SQL> select nvl(max(id), 0) from t;
NVL(MAX(ID),0)
--------------
0
SQL> select nvl(max(id), 0) from t group by client_id;
no rows selected
Usually queries like yours (with max and without group by) are used to avoid no_data_found.
Agregate functions like MAX will always return a row. It will return one row with a null value if no row is found.
By the way SELECT NUM INTO ctr FROM Client; will raise an exception where there's more than one row in the table.
You should instead check whether or not ctr is null.
Others have already explained the reason why your code isn't "working", so I'm not going to be doing that.
You seem to be instituting an identity column of some description yourself, probably in order to support a surrogate key. Doing this yourself is dangerous and could cause large issues in your application.
You don't need to implement identity columns yourself. From Oracle 12c onwards Oracle has native support for identity columns, these are implemented using sequences, which are available in 12c and previous versions.
A sequence is a database object that is guaranteed to provide a new, unique, number when called, no matter the number of concurrent sessions requesting values. Your current approach is extremely vulnerable to collision when used by multiple sessions. Imagine 2 sessions simultaneously finding the largest value in the table; they then both add one to this value and try to write this new value back. Only one can be correct.
See How to create id with AUTO_INCREMENT on Oracle?
Basically, if you use a sequence then you don't need any of this code.
As a secondary note your statement at the top is incorrect:
I have the following function, which returns the next available client ID from the Client table
Your function returns the maximum ID + 1. If there's a gap in the IDs, i.e. 1, 2, 3, 5 then the "missing" number (4 in this case) will not be returned. A gap can occur for any number of reasons (deletion of a row for example) and does not have a negative impact on your database in any way at all - don't worry about them.
I need a query to return boolean when there's table has data in the given range.
Assume table
Customer
[User ID, Name, Date, Products_Purchased]
I'm trying to do:
select case when exists(
select Date, count(*)
from Customer
where date between '2015-08-03' and '2015-08-05'
)
then cast(1 as BIT)
else case(0 as BIT)end;
This is throwing an error near "select Date".
However, weird part is the inner query is running perfectly fine.
Im wondering if im missing out something here !
What about something more straightforward e.g.
select case when count(*) >0 then 1 else 0 end as HIT
from ... where ...
That way you don't have to bother about Hive assuming that EXISTS implies a correlated sub-query, automagically translated into a MapJoin, i.e. a Java HashMap shuffled to the 2nd line of Mappers jobs, etc. Not exactly your use case.
Then it's not useful to compute the exact count, so the query could be refined as
select case when count(*) >0 then 1 else 0 end as HIT
from
(select ... from ... where ... limit 1) X
[Edit] There is no "bit" datatype in Hive. But the default "int" should be OK if you just want a return flag (zero / non-zero)
I have a query that in the select statement uses a custom built function to return one of the values.
The problem I have is every now and then this function will error out because it returns more than one row of information. SQL Error: ORA-01422: exact fetch returns more than requested number of rows
To further compound the issue I have checked the table data within the range that this query should be running and can't find any rows that would duplicate based on the where clause of this Function.
So I would like a quick way to identify on which Row of the original query this crashes so that I can take the values from that query that would be passed into the function and rebuild the Functions query with these values to get it's result and see which two or more rows are returned.
Any ideas? I was hoping there could be a way to force Oracle to process one row at a time until it errors so you can see the results UP to the first error.
Added the code:
FUNCTION EFFPEG
--Returns Effective Pegged Freight given a Effdate, ShipTo, Item
DATE1 IN NUMBER -- Effective Date (JULIANDATE)
, SHAN IN NUMBER -- ShipTo Number (Numeric)
, ITM IN NUMBER -- Short Item Number (Numeric)
, AST IN VARCHAR -- Advance Pricing type (varchar)
, MCU IN VARCHAR Default Null --ShipFrom Plant (varchar)
) RETURN Number
IS
vReturn Number;
BEGIN
Select ADFVTR/10000
into vReturn
from PRODDTA.F4072
where ADEFTJ <= DATE1
and ADEXDJ >= DATE1
and ADAN8 = SHAN and ADITM = ITM
and TRIM(ADAST) = TRIM(AST)
and ADEXDJ = (
Select min(ADEXDJ) ADEXDJ
from PRODDTA.F4072
where ADEFTJ <= DATE1
and ADEXDJ >= DATE1
and ADAN8 = SHAN
and ADITM = ITM
and TRIM(ADAST) = TRIM(AST));
Query that calls this code and passes in the values is:
select GLEXR, ORDTYPE,
EFFPEG(SDADDJ, SDSHAN, SDITM, 'PEGFRTT', SDMCU),
from proddta.F42119
I think the best way to do it is trough Exceptions.
What you need to do is to add the code to handle many rows exception in your function:
EXCEPTION
WHEN TOO_MANY_ROWS THEN
INSERT INTO ERR_TABLE
SELECT your_columns
FROM query_that_sometimes_returns_multiple_rows
In this example the doubled result will go to separated table or you can decide to simply print out with dbms_output.
An easy page to start can be this, then just google exception and you should be able to find all you need.
Hope this can help.