I'm trying to find rows where a value in table 1 column A are not in table 2 column A
This is the query...
SELECT contactsid
FROM contacts
WHERE (email1 NOT IN (SELECT email
FROM old_contact))
It returns 0 rows, which I know is incorrect. There are many rows in contacts.email1 that are not in old_contact.email
How should I be writing this query?
My guess is that old_contract.email takes on a NULL value.
For this reason, not exists is often a better choice:
SELECT contactsid
FROM contacts c
WHERE NOT EXISTS (SELECT 1
FROM old_contract oc
WHERE c.email = oc.email1
) ;
You could also add where email1 is not null to the subquery. However, I find just using not exists is generally safer in case I forget that condition.
Try:
SELECT contactsid
FROM Contacts a
LEFT JOIN old_contact b
ON a.email1 = b.email
WHERE b.email IS NULL
This will join Contacts to old_contact using a LEFT JOIN -- a type of join that, based on the join condition, returns all records from the left side (i.e. Contacts) even if no records exist on the right side. Then, the WHERE clause filters the results so that it returns only the records from the left side where the ride side records don't exist.
Related
My application generates the following SQL-request to get the records matching teamkey:
select cr.callid, t.teamname, u.userfirstname
from callrecord cr
left join agentrecord ar on cr.callid = ar.callid
left join users u on ar.agentkey = u.userkey
left join teams t on u.teamkey = t.teamkey
where t.teamkey in (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16)
This works fine.
When I tried to get the records NOT matching teamkey, the first idea was:
select cr.callid, t.teamname, u.userfirstname
from callrecord cr
left join agentrecord ar on cr.callid = ar.callid
left join users u on ar.agentkey = u.userkey
left join teams t on u.teamkey = t.teamkey
where t.teamkey not in (1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16)
This returns no data. Seems this requires completely different SQL request.
Please help to switch my mind in proper direction.
Record from callrecord table may have no matching record in agentrecord table, also record from users table may have no matching record in teams table, but I want them in the output.
Your query should work, for example a team key of 17 should be returned.
The condition is not exactly the negation of the original because in SQL null values never compare as true (look up SQL three-valued logic, they evaluate as unknown).
Only is null and is distinct from (standard but not supported by most RDBMS) can be used to compare nulls.
So the only rows you might be missing are those that don't have a team. If teamkey is null (in the table or because one of the join did not match), it would not be returned.
You can get those results back by changing your condition to t.teamkey not in (...) or t.teamkey is null
I have 1 table where I have to show the value of 1 ID if another ID is null.
The result of that CASE I then need to use to join with a second table that has the same ID as pid.
I'm stuck and can't quite figure this out. Can someone assist in helping me correct this so it works?
My query is below:
SELECT
fa.name, fa.email_address,
CASE
WHEN pl.main_ID IS NULL THEN pl.sub_ID
ELSE pl.main_ID
END as pid ,pl.*
FROM TableA pl
INNER JOIN TableB fa ON fa.parent_account_sid = pl.pid
Use a lateral join (i.e. apply):
SELECT fa.name, fa.email_address, v.pid, pl.*
FROM TableA pl CROSS APPLY
(VALUES (COALESCE(pl.main_ID, pl.sub_ID)) v(pid) JOIN
TableB fa
ON fa.parent_account_sid = v.pid;
Of course, you might find the COALESCE() to be simple enough that just repeating it isn't an issue.
I guess the problem comes down to this: what are some extreme scenarios where using a LEFT OUTER JOIN DOES NOT return the values as expected? Because in the result set I'm expecting the fields I joined on (item and ID) + any NULL values where the rows don't match, but item and ID don't show up.
Info:
qry_HersheySAPMaxDate2 returns 95 rows.
qry_HersheySAPMaxDate2 could have NULL values for MaxOfMaxOfjob_Date, SumOfSumOfqty_on_hand, product_code, and whse, whereas ID and item will always have a value.
qry_HersheySAPMaxDate3 returns 85 rows.
qry_HersheySAPMaxDate3 does not have any NULL values in any field, but excludes 10 id and item rows.
The query:
SELECT
qry_HersheySAPMaxDate3.ID,
qry_HersheySAPMaxDate3.item,
qry_HersheySAPMaxDate3.MaxOfMaxOfjob_date, qry_HersheySAPMaxDate3.SumOfSumOfqty_on_hand, qry_HersheySAPMaxDate3.product_code,
qry_HersheySAPMaxDate3.whse,
qry_HersheySAPMaxDate3.jobnumber
FROM
qry_HersheySAPMaxDate2
LEFT JOIN qry_HersheySAPMaxDate3 ON (qry_HersheySAPMaxDate2.item = qry_HersheySAPMaxDate3.item) AND (qry_HersheySAPMaxDate2.ID = qry_HersheySAPMaxDate3.ID);
Result set using my query + the suggestion in one of the answers to use LEFT OUTER JOIN instead:
Screenshot
You complain about your query producing entirely blank rows. Let's see why:
You outer join qry3 to qry2. That means when there is no match for a qry2 record in qry3, then a pseudo qry3 record with all columns set to null gets joined.
In your query you select only fields from qry3, so in an outer join case they are all null. Select qry2.ID and qry2.item instead of qry3.ID and qry3.item to see the values that have no match:
SELECT
qry_HersheySAPMaxDate2.ID,
qry_HersheySAPMaxDate2.item,
You should use LEFT OUTER JOIN if you want the NULL values to be included in the result
I have this query:
SELECT
EnrollmentID, MarketID
FROM
Contracts AS CO
LEFT JOIN
Customers AS C ON C.EnrollmentID = CO.BatchID AND MarketID = 'AB'
WHERE
C.EnrollmentID IS NULL
Here, I have a question that in this query is it possible that the query will verify data for MarketID = 'AB' in left join because as per WHERE condition?
I am getting result of EnrollmentIDs and MarketIDs are all NULL.
Note: The LEFT JOIN keyword returns all the rows from the left table (Contracts ), even if there are no matches in the right table (Customers ).
Now, if you want to select right table column and there are no matching data in the right table ,like.
SELECT CO.EnrollmentID, CO.MarketID ,C.Some_col
FROM Contracts AS CO
LEFT JOIN Customers AS C ON C.EnrollmentID = CO.BatchID
so, C.Some_col column will get all the null value for no matching rows in the right table.i think this is the reason why you are getting the null value for
MarketIDs and EnrollmentIDs.
hope, this help you.
I am trying to filter a single table (master) by the values in multiple other tables (filter1, filter2, filter3 ... filterN) using only joins.
I want the following rules to apply:
(A) If one or more rows exist in a filter table, then include only those rows from the master that match the values in the filter table.
(B) If no rows exist in a filter table, then ignore it and return all the rows from the master table.
(C) This solution should work for N filter tables in combination.
(D) Static SQL using JOIN syntax only, no Dynamic SQL.
I'm really trying to get rid of dynamic SQL wherever possible, and this is one of those places I truly think it's possible, but just can't quite figure it out. Note: I have solved this using Dynamic SQL already, and it was fairly easy, but not particularly efficient or elegant.
What I have tried:
Various INNER JOINS between master and filter tables - works for (A) but fails on (B) because the join removes all records from the master (left) side when the filter (right) side has no rows.
LEFT JOINS - Always returns all records from the master (left) side. This fails (A) when some filter tables have records and some do not.
What I really need:
It seems like what I need is to be able to INNER JOIN on each filter table that has 1 or more rows and LEFT JOIN (or not JOIN at all) on each filter table that is empty.
My question: How would I accomplish this without resorting to Dynamic SQL?
In SQL Server 2005+ you could try this:
WITH
filter1 AS (
SELECT DISTINCT
m.ID,
HasMatched = CASE WHEN f.ID IS NULL THEN 0 ELSE 1 END,
AllHasMatched = MAX(CASE WHEN f.ID IS NULL THEN 0 ELSE 1 END) OVER ()
FROM masterdata m
LEFT JOIN filtertable1 f ON join_condition
),
filter2 AS (
SELECT DISTINCT
m.ID,
HasMatched = CASE WHEN f.ID IS NULL THEN 0 ELSE 1 END,
AllHasMatched = MAX(CASE WHEN f.ID IS NULL THEN 0 ELSE 1 END) OVER ()
FROM masterdata m
LEFT JOIN filtertable2 f ON join_condition
),
…
SELECT m.*
FROM masterdata m
INNER JOIN filter1 f1 ON m.ID = f1.ID AND f1.HasMatched = f1.AllHasMatched
INNER JOIN filter2 f2 ON m.ID = f2.ID AND f2.HasMatched = f2.AllHasMatched
…
My understanding is, filter tables without any matches simply must not affect the resulting set. The output should only consist of those masterdata rows that have matched all the filters where matches have taken place.
SELECT *
FROM master_table mt
WHERE (0 = (select count(*) from filter_table_1)
OR mt.id IN (select id from filter_table_1)
AND (0 = (select count(*) from filter_table_2)
OR mt.id IN (select id from filter_table_2)
AND (0 = (select count(*) from filter_table_3)
OR mt.id IN (select id from filter_table_3)
Be warned that this could be inefficient in practice. Unless you have a specific reason to kill your existing, working, solution, I would keep it.
Do inner join to get results for (A) only and do left join to get results for (B) only (you will have to put something like this in the where clause: filterN.column is null) combine results from inner join and left join with UNION.
Left Outer Join - gives you the MISSING entries in master table ....
SELECT * FROM MASTER M
INNER JOIN APPRENTICE A ON A.PK = M.PK
LEFT OUTER JOIN FOREIGN F ON F.FK = M.PK
If FOREIGN has keys that is not a part of MASTER you will have "null columns" where the slots are missing
I think that is what you looking for ...
Mike
First off, it is impossible to have "N number of Joins" or "N number of filters" without resorting to dynamic SQL. The SQL language was not designed for dynamic determination of the entities against which you are querying.
Second, one way to accomplish what you want (but would be built dynamically) would be something along the lines of:
Select ...
From master
Where Exists (
Select 1
From filter_1
Where filter_1 = master.col1
Union All
Select 1
From ( Select 1 )
Where Not Exists (
Select 1
From filter_1
)
Intersect
Select 1
From filter_2
Where filter_2 = master.col2
Union All
Select 1
From ( Select 1 )
Where Not Exists (
Select 1
From filter_2
)
...
Intersect
Select 1
From filter_N
Where filter_N = master.colN
Union All
Select 1
From ( Select 1 )
Where Not Exists (
Select 1
From filter_N
)
)
I have previously posted a - now deleted - answer based on wrong assumptions on you problems.
But I think you could go for a solution where you split your initial search problem into a matter of constructing the set of ids from the master table, and then select the data joining on that set of ids. Here I naturally assume you have a kind of ID on your master table. The filter tables contains the filter values only. This could then be combined into the statement below, where each SELECT in the eligble subset provides a set of master ids, these are unioned to avoid duplicates and that set of ids are joined to the table with data.
SELECT * FROM tblData INNER JOIN
(
SELECT id FROM tblData td
INNER JOIN fa on fa.a = td.a
UNION
SELECT id FROM tblData td
INNER JOIN fb on fb.b = td.b
UNION
SELECT id FROM tblData td
INNER JOIN fc on fc.c = td.c
) eligible ON eligible.id = tblData.id
The test has been made against the tables and values shown below. These are just an appendix.
CREATE TABLE tblData (id int not null primary key identity(1,1), a varchar(40), b datetime, c int)
CREATE TABLE fa (a varchar(40) not null primary key)
CREATE TABLE fb (b datetime not null primary key)
CREATE TABLE fc (c int not null primary key)
Since you have filter tables, I am assuming that these tables are probably dynamically populated from a front-end. This would mean that you have these tables as #temp_table (or even a materialized table, doesn't matter really) in your script before filtering on the master data table.
Personally, I use the below code bit for filtering dynamically without using dynamic SQL.
SELECT *
FROM [masterdata] [m]
INNER JOIN
[filter_table_1] [f1]
ON
[m].[filter_column_1] = ISNULL(NULLIF([f1].[filter_column_1], ''), [m].[filter_column_1])
As you can see, the code NULLs the JOIN condition if the column value is a blank record in the filter table. However, the gist in this is that you will have to actively populate the column value to blank in case you do not have any filter records on which you want to curtail the total set of the master data. Once you have populated the filter table with a blank, the JOIN condition NULLs in those cases and instead joins on itself with the same column from the master data table. This should work for all the cases you mentioned in your question.
I have found this bit of code to be faster in terms of performance.
Hope this helps. Please let me know in the comments.