Using postgres
The following SQL creates TestsTodo, having all the informations about a table tests.
It also have a TestsTodoIds, having only the ids of TestsTodo
Then, i want to update all the rows of a table "test_results", with all the ids in TestsTodoIds. I can do it by setting "WHERE test_id IN (select id from TestsTodo)" But i cant do it with "WHERE test_id IN TestsTodoIds", which is basically the same, i don't understand why.
WITH
TestsTodo AS
(
-- Selecting from table tests
),
TestsTodoIds AS
(
SELECT id FROM TestsTodo -- This returns all the. ids from TestsTodo
)
--UPDATE test_results
--SET status = 'FOUND_IN_DB'
--WHERE test_id IN (SELECT id FROM TestsTodo)
--RETURNING *
-- This works
UPDATE test_results
SET status = 'FOUND_IN_DB'
WHERE test_id IN TestsTodoIds
RETURNING * -- This does not
Error: ERROR: syntax error at or near "TestsTodoIds"
LINE 31: WHERE test_id IN TestsTodoIds
^
Your CTE called TestsTodoIds is a virtual table with one column. It isn't a set of values, and IN needs a set of values. You could use
WHERE test_id IN (SELECT id FROM TestsTodoIds)
and your query would function correctly.
That CTE is, in my opinion, unnecessary. The WHERE clause I suggested will perform exactly the same as
WHERE test_id IN (SELECT id FROM TestsTodo)
and you'll have less complexity to cope with when reading and reasoning about the query.
Related
Hi I want to update all the values of RequestId column of IIL_CHANGE_REQUEST Table with the RequestId of TABLE_NAME_4MINS Table where REQUESTBY column in both tables are same. I am trying to do this in oracle daatabalse(sql developer)
My query:
Update IIL_CHANGE_REQUEST
set REQUESTID=(SELECT TABLE_NAME_4MINS.REQUESTID
FROM TABLE_NAME_4MINS
WHERE IIL_CHANGE_REQUEST.REQUESTBY = TABLE_NAME_4MINS.REQUESTBY)
WHERE EXISTS (SELECT TABLE_NAME_4MINS.REQUESTID
FROM TABLE_NAME_4MINS
WHERE IIL_CHANGE_REQUEST.REQUESTBY = TABLE_NAME_4MINS.REQUESTBY)
But every time I do this I get an error saying:
Error starting at line : 1 in command -
Update IIL_CHANGE_REQUEST
set REQUESTID=(SELECT TABLE_NAME_4MINS.REQUESTID
FROM TABLE_NAME_4MINS
WHERE IIL_CHANGE_REQUEST.REQUESTBY = TABLE_NAME_4MINS.REQUESTBY)
WHERE EXISTS (SELECT TABLE_NAME_4MINS.REQUESTID
FROM TABLE_NAME_4MINS
WHERE IIL_CHANGE_REQUEST.REQUESTBY = TABLE_NAME_4MINS.REQUESTBY)
Error report -
ORA-01427: single-row subquery returns more than one row
Please anyone help how can I do it.
It depends on what you want to do in such cases. If you don't really care, take any value, for example minimum:
update iil_change_request a
set a.requestid = (select min(b.requestid) --> here
from table_name_4mins b
where a.requestby = b.requestby)
where exists (select c.requestid
from table_name_4mins c
where a.requestby = c.requestby);
If that's not what you want, then you'll have to figure out what to do with those "duplicates". Perhaps you'll have to include yet another WHERE condition, or fix data, or ... who knows? I don't, while you should.
You need to find a condition to narrow down returned rows to the only per REQESTSTBY, for example you can replace ... with a column name in the query below to return just first row as per order-by:
MERGE INTO IIL_CHANGE_REQUEST r
USING (
SELECT *
FROM (
SELECT REQUESTBY, REQUESTID
,row_number()over(partition by REQUESTBY order by ...) rn
FROM TABLE_NAME_4MINS
)
where rn=1
) t
ON (r.REQUESTBY = t.REQUESTBY)
WHEN MATCHED THEN UPDATE
set REQUESTID=t.REQUESTID;
I would like to update rows with values chosen randomly from a set of possible values.
Ideally I would be able to provide this values at runtime, using JdbcTemplate from Java application.
Example:
In a table, column "name" can contain any name. The goal is to run through the table and change all names to equal to either "Bob" or "Alice".
I know that this can be done by creating a sql function. I tested it and it was fine but I wonder if it is possible to just use simple query?
This will not work, seems that the value is computed once, and applied to all rows:
UPDATE test.table
SET first_name =
(SELECT a.name
FROM
(SELECT a.name, RAND() idx
FROM (VALUES('Alice'), ('Bob')) AS a(name) ORDER BY idx FETCH FIRST 1 ROW ONLY) as a)
;
I tried using MERGE INTO, but it won't even run (possible_names is not found in SET query). I am yet to figure out why:
MERGE INTO test.table
USING
(SELECT
names.fname
FROM
(VALUES('Alice'), ('Bob'), ('Rob')) AS names(fname)) AS possible_names
ON ( test.table.first_name IS NOT NULL )
WHEN MATCHED THEN
UPDATE SET
-- select random name
first_name = (SELECT fname FROM possible_names ORDER BY idx FETCH FIRST 1 ROW ONLY)
;
EDIT: If possible, I would like to only focus on fields being updated and not depend on knowing primary keys and such.
Db2 seems to be optimizing away the subselect that returns your supposedly random name, materializing it only once, hence all rows in the target table receive the same value.
To force subselect execution for each row you need to somehow correlate it to the table being updated, for example:
UPDATE test.table
SET first_name =
(SELECT a.name
FROM (VALUES('Alice'), ('Bob')) AS a(name)
ORDER BY RAND(ASCII(SUBSTR(first_name, 1, 1)))
FETCH FIRST 1 ROW ONLY)
or may be even
UPDATE test.table
SET first_name =
(SELECT a.name
FROM (VALUES('Alice'), ('Bob')) AS a(name)
ORDER BY first_name, RAND()
FETCH FIRST 1 ROW ONLY)
Now that the result of subselect seems to depend on the value of the corresponding row in the target table, there's no choice but to execute it for each row.
If your table has a primary key, this would work. I've assumed the PK is column id.
UPDATE test.table t
SET first_name =
( SELECT name from
( SELECT *, ROW_NUMBER() OVER(PARTITION BY id ORDER BY R) AS RN FROM
( SELECT *, RAND() R
FROM test.table, TABLE(VALUES('Alice'), ('Bob')) AS d(name)
)
)
AS u
WHERE t.id = u.id and rn = 1
)
;
There might be a nicer/more efficient solution, but I'll leave that to others.
FYI I used the following DDL and data to test the above.
create table test.table(id int not null primary key, first_name varchar(32));
insert into test.table values (1,'Flo'),(2,'Fred'),(3,'Sue'),(4,'John'),(5,'Jim');
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 have a small access database with some tables. I am trying the code in the sql design within access. I just want to randomly select a record within a table.
I created a simple table called StateAbbreviation. It has two columns: ID and Abbreviation. ID is just an autonumber and Abbreviation are different abbreviations for states.
I saw this thread here. So I tried
SELECT Abbreviation
FROM STATEABBREVIATION
ORDER BY RAND()
LIMIT 1;
I get the error Syntax error (missing operator) in query expresion RAND() LIMIT 1. So I tired RANDOM() instead of RAND(). Same error.
None of the others worked either. What am I doing wrong? Thanks.
Ypercude provided a link that led me to the right answer below:
SELECT TOP 1 ABBREVIATION
FROM STATEABBREVIATION
ORDER BY RND(ID);
Note that for RND(), I believe that it has to be an integer value/variable.
You need both a variable and a time seed to not get the same sequence(s) each time you open Access and run the query - and to use Access SQL in Access:
SELECT TOP 1 Abbreviation
FROM STATEABBREVIATION
ORDER BY Rnd(-Timer()*[ID]);
where ID is the primary key of the table.
Please try this, it is helpful to you
It is possible by using a stored procedure and function, which I created it's have a extra column which you could be create in your table FLAG name and column all field value should be 0 Then it works
create Procedure proc_randomprimarykeynumber
as
declare #Primarykeyid int
select top 1
#Primarykeyid = u.ID
from
StateAbbreviation u
left join
StateAbbreviation v on u.ID = v.ID + 1
where
v.flag = 1
if(#Primarykeyid is null )
begin
UPDATE StateAbbreviation
SET flag = 0
UPDATE StateAbbreviation
SET flag = 1
WHERE ID IN (SELECT TOP 1 ID
FROM dbo.StateAbbreviation)
END
ELSE
BEGIN
UPDATE StateAbbreviation
SET flag = 0
UPDATE StateAbbreviation
SET flag = 1
WHERE ID IN (#Primarykeyid)
END
SET #Primarykeyid = 1
SELECT TOP 1
ID, Abbreviation
FROM
StateAbbreviation
WHERE
flag = 1
It is made in stored procedure run this and get serial wise primary key
exec proc_randomprimarykeynumber
Thanks and regard
Try this:
SELECT TOP 1 *
FROM tbl_name
ORDER BY NEWID()
Of course this may have performance considerations for large tables.
Please see the table structure below:
CREATE TABLE Person (id int not null, PID INT NOT NULL, Name VARCHAR(50))
CREATE TABLE [Order] (OID INT NOT NULL, PID INT NOT NULL)
INSERT INTO Person VALUES (1,1,'Ian')
INSERT INTO Person VALUES (2,2,'Maria')
INSERT INTO [Order] values (1,1)
Why does the following query return two results:
select * from Person WHERE id IN (SELECT ID FROM [Order])
ID does not exist in Order. Why does the query above produce results? I would expect it to error because I'd does not exist in order.
This behavior, while unintuitive, is very well defined in Microsoft's Knowledge Base:
KB #298674 : PRB: Subquery Resolves Names of Column to Outer Tables
From that article:
To illustrate the behavior, use the following two table structures and query:
CREATE TABLE X1 (ColA INT, ColB INT)
CREATE TABLE X2 (ColC INT, ColD INT)
SELECT ColA FROM X1 WHERE ColA IN (Select ColB FROM X2)
The query returns a result where the column ColB is considered from table X1.
By qualifying the column name, the error message occurs as illustrated by the following query:
SELECT ColA FROM X1 WHERE ColA in (Select X2.ColB FROM X2)
Server: Msg 207, Level 16, State 3, Line 1
Invalid column name 'ColB'.
Folks have been complaining about this issue for years, but Microsoft isn't going to fix it. It is, after all, complying with the standard, which essentially states:
If you don't find column x in the current scope, traverse to the next outer scope, and so on, until you find a reference.
More information in the following Connect "bugs" along with multiple official confirmations that this behavior is by design and is not going to change (so you'll have to change yours - i.e. always use aliases):
Connect #338468 : CTE Column Name resolution in Sub Query is not validated
Connect #735178 : T-SQL subquery not working in some cases when IN operator used
Connect #302281 : Non-existent column causes subquery to be ignored
Connect #772612 : Alias error not being reported when within an IN operator
Connect #265772 : Bug using sub select
In your case, this "error" will probably be much less likely to occur if you use more meaningful names than ID, OID and PID. Does Order.PID point to Person.id or Person.PID? Design your tables so that people can figure out the relationships without having to ask you. A PersonID should always be a PersonID, no matter where in the schema it is; same with an OrderID. Saving a few characters of typing is not a good price to pay for a completely ambiguous schema.
You could write an EXISTS clause instead:
... FROM dbo.Person AS p WHERE EXISTS
(
SELECT 1 FROM dbo.[Order] AS o
WHERE o.PID = p.id -- or is it PID? See why it pays to be explicit?
);
The problem here is that you're not using Table.Column notation in your subquery, table Order doesn't have column ID and ID in subquery really means Person.ID, not [Order].ID. That's why I always insist on using aliases for tables in production code. Compare these two queries:
select * from Person WHERE id IN (SELECT ID FROM [Order]);
select * from Person as p WHERE p.id IN (SELECT o.ID FROM [Order] as o)
The first one will execute but will return incorrect results, and the second one will raise an error. It's because the outer query's columns may be referenced in a subquery, so in this case you can use Person columns inside the subquery.
Perhaps you wanted to use the query like this:
select * from Person WHERE pid IN (SELECT PID FROM [Order])
But you never know when the schema of the [Order] table changes, and if somebody drops the column PID from [Order] then your query will return all rows from the table Person. Therefore, use aliases:
select * from Person as P WHERE P.pid IN (SELECT O.PID FROM [Order] as O)
Just quick note - this is not SQL Server specific behaviour, it's standard SQL:
SQL Server demo
PostgreSQL demo
MySQL demo
Oracle demo
Order table doesnt have id column
Try these instead:
select * from Person WHERE id IN (SELECT OID FROM [Order])
OR
select * from Person WHERE pid IN (SELECT PID FROM [Order])