I have the following query which inserts data into one table after selecting it from another.
The problem is that the data types do not match for one of the columns. I have simplified the query below.
INSERT INTO tbl.LogTable (
[SelPartNo], -- This does not match, see below
)
SELECT TOP 1
IF([SelPartNo] = 'False', NULL, [SelPartNo],
FROM tbl.MyTable
WHERE ID = '20358'
ORDER BY CreateDate DESC
The first SelPartNo is an int and the second is a VarChar. In most instances the SelPartNo for the second one (tbl.MyTable) is NULL or an integer, which I don't think will cause a problem. But in some cases the value is "False", which needs to return NULL.
I have tried an IF statement but I am doing something wrong because it's giving a syntax error and I am unsure if this is the correct approach.
Your code is syntactically incorect...
Try it with
NULLIF([SelPartNo],'False')
This function returns NULL if the two expressions are equal.
Details: https://msdn.microsoft.com/en-us/library/ms177562.aspx
I don't think IF is a function, at least not one which you can use in a SELECT statement. But CASE WHEN ... END is your friend:
INSERT INTO tbl.LogTable (
[SelPartNo]
)
SELECT TOP 1
CASE WHEN [SelPartNo] = 'False' THEN NULL ELSE [SelPartNo] END
FROM tbl.MyTable
WHERE ID = '20358'
ORDER BY CreateDate DESC
Related
I have a stored procedure which takes in five parameters of which two can be null - we will call these parameters A and B
What I would like to do is select records based on the following logic.
If Parameter A is NULL then only return records that match Parameter B
I know that I can do something similar to the following
IF A IS NULL
BEGIN
SELECT * FROM TABLE WHERE Param=B
END
ELSE
BEGIN
SELECT * FROM TABLE WHERE Param=A
END
However, the SQL query is much more complex then the above one and there would be huge replication in the Proc which is something I want to avoid
Thanks in advance
===============================
EDIT - Sorry, I should have mentioned that in the example the Param are based on separate columns e.g.
My table consists of four columns of which two separate columns map to the two parameters - basic schema below
ID
PersonName
GroupID
DeliveryID
In my procedure I want to retrieve those records that match the GroupID however in the scenario where the GroupID is null then I want to return those records that match the DeliveryID
Thanks again
Try
SELECT * FROM my_table WHERE Param = COALESCE(A,B)
COALESCE will give you A if it's not null. Otherwise B.
Functionally, something like this should work. If either parameter is NULL, the condition becomes a self-identity (assuming neither groupID nor deliveryID is NULL).
SELECT *
FROM table_name
WHERE groupID = coalesce(#groupIDParameter, groupID)
AND deliveryID = coalesce(#deliveryIDParameter, deliveryID)
Try ISNULL function:
SELECT * FROM TABLE WHERE Param = ISNULL(B,A)
You could also use a case statement Case when A is Null Then B
In SQL Server, if my SELECT statement in a subquery returns no row, is then the result of the subquery equal to NULL? I made some research, but I am not sure about it.
Example:
IF (SELECT TOP 1 CLMN1 FROM SOMETABLE) IS NOT NULL THEN
....
I am asking to understand the behaviour of the if-statement above.
Looks like the answer is yes:
DECLARE #Test TABLE (Id INT)
INSERT INTO #Test VALUES (1)
SELECT * FROM #Test WHERE Id = 2
SELECT CASE WHEN (SELECT * FROM #Test WHERE Id = 2) IS NULL THEN 1 ELSE 0 END
EDIT: after you updated your question I think I should add that instead of checking if there are rows with IS NULL you should use the following that can be better optimised by the server:
IF EXISTS(SELECT * FROM #Test WHERE Id = 2)
BEGIN
-- Whatever
END
NULL means no value, for example that the "box" for a certain column in a certain row is empty. NO ROW means that there are no rows.
No, NULL is a column value that indicates that the value of that column for a given row has no valid value. There would have to be a row returned by your query for that row to contain NULL column values.
A query that returns no rows just means that no rows matched the predicate you used in the query and therefore no data was returned at all.
Edit: After the question was edited, my answer doesn't address the specific case called out in the question. Juan's answer above does.
I have a problem about my query and i dont know what to do about it.Here is my query.and error i take.
select prd.product_id,prd.prd_name ,prd.prd_longname ,prd.prd_brand ,prd.prd_picture ,prd.market_comment ,prd.categ ,prd.status_id ,prd.status ,prd.active_stock ,prd.slot_date ,prd.currency ,prd.selling_price ,prd.old_price ,prd.type_of_sell ,prd.catalog_id ,prd.catalog_name ,prd.demo ,prd.demo_id,
(select coalesce(count(prd_attribute_id),0) from PRD_ATTRIBUTE where status_id = 1 and product_id = prd.product_id and batch_code <> '0000') as ATTR_CNT ,
(select prd_attribute_id from PRD_ATTRIBUTE where product_id = prd.product_id and batch_code = '0000' and status_id = 1),
(select categ_url from DBNAME.PRD_CATEGORY
where parameter_id = prd.categ_id)||'/'|| (select prd_url from DBNAME.PRODUCT_URL where product_id = prd.product_id) as CATEG_URL
from TEMP_WEB_PRD prd
order by slotdate desc
fetch first 12 rows only
Error:
[IBM][CLI Driver][DB2/AIX64] SQL0811N The result of a scalar fullselect, SELECT INTO statement, or VALUES INTO statement is more than one row. SQLSTATE=21000
The error message is pretty self-explanatory. One of your sub-selects is returning more than one row back, and the database doesn't know how to handle that. I'm guessing your database is DB2 on Linux/Unix/Windows, based on the error message, so here's the Info Center article on your error.
Yes in short it's due to you are using "=" but duplicate rows returned from sub-select statement.
Suppose you have a simple table:
create table T1 (ID int not null primary key, FID int);
The following statement may return SQL0811N if FID column references the same ID values multiple times.
db2 "select id from T1 where ID=(select fid from T1)"
ID
SQL0811N The result of a scalar fullselect, SELECT INTO statement, or VALUES
INTO statement is more than one row. SQLSTATE=21000
The following statement will run successfully:
db2 "select id from T1 where ID IN (select fid from T1)"
Maybe one of your tables has duplicate data, make sure you've checked it. I have the same problem too, it is caused by duplicate rows and it makes subquery return more than one row.
I am trying to get a random id value from my table. The condition is that the selected value must not exist for the same id and different language (language is lang field)
I do this:
SELECT id_v as p,cont FROM value_phrase WHERE lang=1 AND
NULL IN (SELECT cont FROM value_phrase WHERE id_v=p AND lang=2)
ORDER BY RAND() LIMIT 0,1
... but I do not get any results (It must be an error in my query, because there are many rows satisfying the desired condition.) How should I fix it?
-- SOLVED --
the solution is to use NOT EXISTS instead of NULL IN, and use table aliases to refer the first id_v into the sub query. This way (thanks to Mark Byers):
SELECT first.id_v, first.cont
FROM value_phrase AS
FIRST WHERE lang =1
AND NOT
EXISTS (
SELECT cont
FROM value_phrase
WHERE id_v = first.id_v
AND lang =2
)
ORDER BY RAND( )
LIMIT 0 , 1
If you want to check if a value does not exist, use NOT EXISTS.
AND NOT EXISTS (SELECT ... )
Your condition NULL IN (...) will never return anything, because a comparison with NULL always returns NULL and that is treated as "false" in a query condition.
I am attempting to use a case statement but keep getting errors. Here's the statement:
select TABLE1.acct,
CASE
WHEN TABLE1.acct_id in (select acct_id
from TABLE2
group by acct_id
having count(*) = 1 ) THEN
(select name
from TABLE3
where TABLE1.acct_id = TABLE3.acct_id)
ELSE 'All Others'
END as Name
from TABLE1
When I replace the TABLE1.acct_id in the THEN expression with a literal value, the query works. When I try to use TABLE1.acct_id from the WHEN part of the query, I get a error saying the result is more than one row. It seems like the THEN expression is ignoring the single value that the WHEN statement was using. No idea, maybe this isn't even a valid use of the CASE statement.
I am trying to see names for accounts that have one entry in TABLE2.
Any ideas would be appreciated, I'm kind of new at SQL.
First, you are missing a comma after TABLE1.acct. Second, you have aliased TABLE1 as acct, so you should use that.
Select acct.acct
, Case
When acct.acct_id in ( Select acct_id
From TABLE2
Group By acct_id
Having Count(*) = 1 )
Then ( Select name
From TABLE3
Where acct.acct_id = TABLE3.acct_id
Fetch First 1 Rows Only)
Else 'All Others'
End as Name
From TABLE1 As acct
As others have said, you should adjust your THEN clause to ensure that only one value is returned. You can do that by add Fetch First 1 Rows Only to your subquery.
Then ( Select name
From TABLE3
Where acct.acct_id = TABLE3.acct_id
Fetch First 1 Rows Only)
Fetch is not accepting in CASE statement - "Keyword FETCH not expected. Valid tokens: ) UNION EXCEPT. "
select name from TABLE3 where TABLE1.acct_id = TABLE3.acct_id
will give you all the names in Table3, which have a accompanying row in Table 1. The row selected from Table2 in the previous line doesn't enter into it.
Must be getting more than one value.
You can replace the body with...
(select count(name) from TABLE3 where TABLE1.acct_id = TABLE3.acct_id)
... to narrow down which rows are returning multiples.
It may be the case that you just need a DISTINCT or a TOP 1 to reduce your result set.
Good luck!
I think that what is happening here is that your case must return a single value because it will be the value for the "name" column. The subquery (select acct_id from TABLE2 group by acct_id having count(*) = 1 ) is OK because it will only ever return one value. (select name from TABLE3 where TABLE1.acct_id= TABLE3.acct_id) could return multiple values depending on your data. The problem is you trying to shove multiple values into a single field for a single row.
The next thing to do would be to find out what data causes multiple rows to be returned by (select name from TABLE3 where TABLE1.acct_id= TABLE3.acct_id), and see if you can further limit this query to only return one row. If need be, you could even try something like ...AND ROWNUM = 1 (for Oracle - other DBs have similar ways of limiting rows returned).