I'm trying to determine if a table in my SQL Server 2012 database has any records that don't exist in a table that's on a linked Oracle 11g database.
I tried to do this with the following:
select 1
from my_order_table ord
where not exists (select 1
from LINK_ORA..[SCHEMA1].[ORDERS]
where doc_id = ord.document_id)
and document_id = 'N2324JKL3511'
The issue is that it never completes because the ORDERS table on the linked server has about 100 million rows and as per the explain plan on SQL Server, it is trying to pull back the entire ORDERS table from the linked server and then apply the WHERE clause.
As per the explain plan, it views the remote table as having an estimated 10000 rows - I assume that's some kind of default if it is unable to get statistics..?
Even running something as simple as this:
select 1 from LINK_ORA..[SCHEMA1].[ORDERS] where doc_id = 'N2324JKL3511'
causes SQL Server to not send the WHERE clause and the query never completes.
I tried to use OPENQUERY however it won't let me add the doc_id to concatenate into the WHERE clause of the query string.
Then I tried to build a select FROM OPENQUERY string in a function but I can't use sp_executesql in a function to run it.
Any help is greatly appreciated.
I think this would logically work for you, but it may take too long as well.
SELECT sql_ord.*
FROM my_order_table sql_ord
LEFT JOIN LINK_ORA..[SCHEMA1].[ORDERS] ora_ord ON sql_ord.document_id = ora_ord.doc_id
WHERE sql_ord.document_id = 'N2324JKL3511'
AND ora_ord.doc_id IS NULL
Since you have problem with something as simple as select 1 from LINK_ORA..[SCHEMA1].[ORDERS] where doc_id = 'N2324JKL3511' have you try to create a table on the remote server that will hold the doc_id that you want to look at. So your SELECT will include a table that contain only 1 row. I'm just not sure about the INSERT since I can't test it for now. I'm assuming that everything will be done on the remote server.
So something like :
CREATE TABLE LINK_ORA..[SCHEMA1].linked_server_doc_id (
doc_id nvarchar(12));
INSERT INTO LINK_ORA..[SCHEMA1].linked_server_doc_id (doc_id)
SELECT doc_id
FROM LINK_ORA..[SCHEMA1].[ORDERS] WHERE doc_id = 'N2324JKL3511';
select 1
from my_order_table ord
where not exists (select 1
from LINK_ORA..[SCHEMA1].[linked_server_doc_id]
where doc_id = ord.document_id)
and document_id = 'N2324JKL3511';
DROP TABLE LINK_ORA..[SCHEMA1].linked_server_doc_id
I have a table with 9000 items and for test reasons i renamed one object's name into "LOL". Now I want to show me all data records which don't match that string. So, the result has to be 8999 but I only get 620 which is really strange.
Query:
SELECT Count(*) FROM [xxx] WHERE xxx.name = "LOL";
>>Result 1
SELECT Count(*) FROM [xxx] WHERE xxx.name <> "LOL";
>>Result 620
It's a MS Access DB and the datatype of that column is short text.
I really don't get it, why there are so many data records filtered out. It seems like that the NOT EQUAL Operator doesn't work in Access DB. NOT LIKE causes the same result.
Do you have the other columns with null values ?
SELECT Count(*) FROM [xxx] WHERE xxx.name is null or xxx.name <> "LOL";
I have 2 tables in SQL Server: Table 1 and Table 2.
Table 1 has 500 Records and Table 2 has Millions of Records.
Table 2 may/may not have the 500 Records of Table 1 in it.
I have to compare Table 1 and Table 2. But the result should give me only the Records of Table 1 which has any data change in Table 2. Means the Result should be less than or equal to 500.
I don't have any primary key but the columns in the 2 tables are same. I have written the following query. But I am getting time out exception and it is taking much time to process. Please help.
With CTE_DUPLICATE(OLD_FIRSTNAME ,New_FirstName,
OLD_LASTNAME ,New_LastName,
OLD_MINAME ,New_MIName ,
OLD_FAMILYID,NEW_FAMILYID,ROWNUMBER)
as (
Select distinct
OLD.FIRST_NAME AS 'OLD_FIRSTNAME' ,New.First_Name AS 'NEW_FIRSTNAME',
OLD.LAST_NAME AS 'OLD_LASTNAME',New.Last_Name AS 'NEW_LASTNAME',
OLD.MI_NAME AS 'OLD_MINAME',New.MI_Name AS 'NEW_MINAME',
OLD.FAMILY_ID AS 'OLD_FAMILYID',NEW.FAMILY_ID AS 'NEW_FAMILYID',
row_number()over(partition by OLD.FIRST_NAME ,New.First_Name,
OLD.LAST_NAME ,New.Last_Name,
OLD.MI_NAME ,New.MI_Name ,
OLD.FAMILY_ID,NEW.FAMILY_ID
order by OLD.FIRST_NAME ,New.First_Name,
OLD.LAST_NAME ,New.Last_Name,
OLD.MI_NAME ,New.MI_Name ,
OLD.FAMILY_ID,NEW.FAMILY_ID )as rank
From EEMSCDBStatic OLD,EEMS_VIPFILE New where
OLD.MPID <> New.MPID and old.FIRST_NAME <> New.First_Name
and OLD.LAST_NAME <> New.Last_Name and OLD.MI_NAME <> New.MI_Name
and old.Family_Id<>New.Family_id
)
sELECT OLD_FIRSTNAME ,New_FirstName,
OLD_LASTNAME ,New_LastName,
OLD_MINAME ,New_MIName ,
OLD_FAMILYID,NEW_FAMILYID FROM CTE_DUPLICATE where rownumber=1
I think the main problem here is that your query is forcing the DB to fully multiply your tables, which means processing ~500M combinations. It happens because you're connecting any record from T1 with any record from T2 that has at least one different value, including MPID that looks like the unique identifier that must be used to connect records.
If MPID is really the column that identifies records in both tables then your query should have a bit different structure:
SELECT old.FIRSTNAME, new.FirstName,
old.LASTNAME, new.LastName,
old.MINAME, new.MIName,
old.FAMILYID, new.FAMILYID
FROM EEMSCDBStatic old
INNER JOIN EEMS_VIPFILE new ON old.MPID = new.MPID
WHERE old.FIRST_NAME <> New.First_Name
AND OLD.LAST_NAME <> New.Last_Name
AND OLD.MI_NAME <> New.MI_Name
AND old.Family_Id <> New.Family_id
ORDER BY old.FIRSTNAME, new.FirstName,
old.LASTNAME, new.LastName,
old.MINAME, new.MIName,
old.FAMILYID, new.FAMILYID
A couple of other thoughts:
If you're looking for any change in a record (even if only one column has different values), you should use ORs in the WHERE clause, not ANDs. Now you're only looking for records that changed values in all columns. For instance, you'll fail to find a person who changed his or her first name but decided to keep last name.
You should obviously consider indexing your tables if it's possible.
Surely it is pointless to use DISTINCT keyword together with ROWNUMBER.
See this sql query distinct with Row_Number.
You are doing CROSS JOIN, which is terribly big in your case.
Perhaps in that condition you
where OLD.MPID <> New.MPID and old.FIRST_NAME <> New.First_Name and ...
you wanted to have OR instead of AND?
It is also not entirely clear why you use ROWNUMBER at all - perhaps to find the best match.
All this is because as #Shnugo correctly remarked, the logic behind your comparing is faulty - you must have some logic defined that would JOIN the tables (Like First and second name must be the same).
Let's say that we have a table named Data with Id and Weather columns. Other columns in that table are not important to this problem. The Weather column can be null.
I want to display all rows where Weather fits a condition, but if there is a null value in weather then display null value.
My SQL so far:
SELECT *
FROM Data d
WHERE (d.Weather LIKE '%'+COALESCE(NULLIF('',''),'sunny')+'%' OR d.Weather IS NULL)
My results are wrong, because that statement also shows values where Weather is null if condition is not correct (let's say that users mistyped wrong).
I found similar topic, but there I do not find appropriate answer.
SQL WHERE clause not returning rows when field has NULL value
Please help me out.
Your query is correct for the general task of treating NULLs as a match. If you wish to suppress NULLs when there are no other results, you can add an AND EXISTS ... condition to your query, like this:
SELECT *
FROM Data d
WHERE d.Weather LIKE '%'+COALESCE(NULLIF('',''),'sunny')+'%'
OR (d.Weather IS NULL AND EXISTS (SELECT * FROM Data dd WHERE dd.Weather LIKE '%'+COALESCE(NULLIF('',''),'sunny')+'%'))
The additional condition ensures that NULLs are treated as matches only if other matching records exist.
You can also use a common table expression to avoid duplicating the query, like this:
WITH cte (id, weather) AS
(
SELECT *
FROM Data d
WHERE d.Weather LIKE '%'+COALESCE(NULLIF('',''),'sunny')+'%'
)
SELECT * FROM cte
UNION ALL
SELECT * FROM Data WHERE weather is NULL AND EXISTS (SELECT * FROM cte)
statement show also values where Wether is null if condition is not correct (let say that users typed wrong sunny).
This suggests that the constant 'sunny' is coming from end-user's input. If that is the case, you need to parameterize your query to avoid SQL injection attacks.
Debugging an app which queries SQL Server 05, can't change the query but need to optimise things.
Running all the selects seperately are quick <1sec, eg: select * from acscard, select id from employee... When joined together it takes 50 seconds.
Is it better to set uninteresting accesscardid fields to null or to '' when using EXISTS?
SELECT * FROM ACSCard
WHERE NOT EXISTS
( SELECT Id FROM Employee
WHERE Employee.AccessCardId = ACSCard.acs_card_number )
AND NOT EXISTS
( SELECT Id FROM Visit
WHERE Visit.AccessCardId = ACSCard.acs_card_number )
ORDER by acs_card_id
Do you have indexes on Employee.AccessCardId, Visit.AccessCardId, and ACSCard.acs_card_number?
The SELECT clause is not evaluated in an EXISTS clause. This:
WHERE EXISTS(SELECT 1/0
FROM EMPLOYEE)
...should raise an error for dividing by zero, but it won't. But you need to put something in the SELECT clause for it to be a valid query - it doesn't matter if it's NULL or a zero length string.
In SQL Server, NOT EXISTS (and NOT IN) are better than the LEFT JOIN/IS NULL approach if the columns being compared are not nullable (the values on either side can not be NULL). The columns compared should be indexed, if they aren't already.