I am running a script in SQL server from MS Access and not getting the correct results due to FIRST function in MS Access
Select ClientID, ClientREF, FIRST(AgentID) AS FirstOFAgentID, FIRST(AgentREF) AS FirstOFAgentREF
From table 1
Right join table2 ON table1 = table2
Left join table 4 ON table1 = table4
Group by ClientID, ClienREF, AgentID, AgentREF
Your query doesn't make sense. You have FIRST(AgentID), but are including AgentId in the GROUP BY. You query is equivalent to simply SELECT DISTINCT with your columns.
Presuming you really want a first value, I can readily think of in SQL Server, both using window functions. I prefer conditional aggregation:
select ClientID, ClientREF,
max(case when seqnum = 1 then AgentID end) AS FirstOFAgentID, F
max(case when seqnum = 1 then AgentREF end) AS FirstOFAgentREF
from (select ClientID, ClientREF, AgentID, AgentREF,
row_number() over (partition by ClientID, ClientREF order by ?) as seqnum
from table 1 Right join
table2
ON table1 = table2 Left join
table 4
ON table1 = table4
) cc
group by ClientID, ClienREF;
The second uses SELECT DISTINCT with FIRST_VALUE(), which is provided as a window function but not an aggregation function.
Related
I have a simple groupby scenario. Below is the output of the query.
Query is:
select target_date, type, count(*) from table_name group by target_date, type
The query and output is perfectly good.
My problem is I am using this in Grafana for plotting. That is Grafana with postgres as backend.
What happens is since "type2" category is missed on 01-10-2020 and 03-10-2020, type2 category never gets plotted (side to side bar plot) at all. Though "type2" is present in other days.
It is expecting some thing like
So whenever a category is missed in a date, we need a count with 0 value.
Need to handle this in query, as the source data cannot be modified.
Any help here is appreciated.
You need to create a list of all the target_date/type combinations. That can be done with a CROSS JOIN of two DISTINCT selects of target_date and type. This list can beLEFT JOINed to table_name to get counts for each combination:
SELECT dates.target_date, types.type, COUNT(t.target_date)
FROM (
SELECT DISTINCT target_date
FROM table_name
) dates
CROSS JOIN (
SELECT DISTINCT type
FROM table_name
) types
LEFT JOIN table_name t ON t.target_date = dates.target_date AND t.type = types.type
GROUP BY dates.target_date, types.type
ORDER BY dates.target_date, types.type
Demo on dbfiddle
You may use a calendar table approach here:
SELECT
t1.target_date,
t2.type,
COUNT(t3.target_date) AS count
FROM (SELECT DISTINCT target_date FROM yourTable) t1
CROSS JOIN (SELECT DISTINCT type FROM yourTable) t2
LEFT JOIN yourTable t3
ON t3.target_date = t1.target_date AND
t3.type = t2.type
GROUP BY
t1.target_date,
t2.type
ORDER BY
t1.target_date,
t2.type;
The idea here is to cross join subqueries finding all distinct target dates and types, to generate a starting point for the query. Then, we left join this intermediate table to your actual table, and find the counts for each date and type.
select t.target_date, tmp.type, sum(case when t.type = tmp.type then 1 else 0 end)
from your_table t
cross join (select distinct type from your_table) tmp
group by t.target_date, tmp.type
Demo
I am currently trying to join a table to itself to check if for one email there exist two or more Ids.
I am trying to join my table with itself on its email. I then wanted to query my table with a case condition saying if the count of the email in the nested query > 1 then select the latest modified record in the outer table.
SELECT *
FROM table1 <-- outer table
WHERE email IN
(SELECT email, COUNT(*)
FROM table1 as src
INNER JOIN table1 ON src.Email = table1.Email AND src.Id = table1.id
GROUP BY src.Email)
How can I write a query to say if the count for the given email is greater than 1 then select the latest record from the outer table?
Why would you go through all that trouble? How about just selecting the last modified record:
select t1.*
from table1 t1
where t1.modified_dt = (select max(tt1.modified_dt)
from table1 tt1
where tt1.email = t1.email
);
Another way to do it using window functions:
DECLARE #Tab TABLE (ID INT, Email VARCHAR(100), LastModified DATE)
INSERT #Tab
VALUES (1,'testemail#none.com','2019-12-01'),
(2,'testemail#none.com','2019-11-19'),
(3,'otheremail#none.com','2019-12-15')
SELECT *
FROM(
SELECT ROW_NUMBER() OVER(PARTITION BY t.Email ORDER BY t.LastModified DESC) rn, t.*
FROM #Tab t
) t2
WHERE t2.rn = 1
If by latest you mean the latest id number (the maximum number) then this should help you
With cte AS
(
SELECT email,
COUNT(id) OVER (PARTITION BY email) AS CountOfIDs,
ROW_NUMBER() OVER (PARITION BY email ORDER BY ID DESC) AS IdIndex
FROM table1
)
SELECT *
FROM cte
WHERE CountOfIDs > 1 AND IdIndex = 1
I'm trying to make a Join statement that will combine two tables, one being for employee information and the other for job role info. The structure of the tables is as follows:
Table 1
Table 2
I would like to join these two tables in such a way that JobKey and JobValue would be the same row as the associated employee, and not create duplicate rows. Normally, a join statement would create this:
Instead, what i would like is something like this:
Is there an effective way to do this?
Edit:
Here is the query I'm currently using to join them:
select * from testTable1 as a left join testTable2 as b on a.EmployeeName = b.EmployeeName
You can use conditional aggregation:
select t1.*, t2.jobkey_1, t2.jobvalue_1, t2.jobkey_2, t2.jobkey_2
from table1 t1 left join
(select t2.employeename,
max(case when seqnum = 1 then jobkey end) as jobkey_1,
max(case when seqnum = 1 then jobvalue end) as jobvalue_1,
max(case when seqnum = 2 then jobkey end) as jobkey_2,
max(case when seqnum = 2 then jobvalue end) as jobvalue_2,
from (select t2.*, row_number() over (partition by employeename order by rowid) as seqnum
from table2 t2
) t2
group by employeename
) t2;
Note: You appear to be using the employee name as the join key between the tables. You should really be using the employee id.
I'm writing a page that will create a query (for non-db users) and it create the query and run it returning the results for them.
I am using row_number to handle custom pagination.
How do I do a left join and a row_number in a subquery when I don't know the specific columns I need to return. I tried to use * but I get an error that
The column '' was specified multiple times
Here is the query I tried:
SELECT * FROM
(SELECT ROW_NUMBER() OVER (ORDER BY Test) AS ROW_NUMBER, *
FROM table1 a
LEFT JOIN table2 b
ON a.ID = b.ID) x
WHERE ROW_NUMBER BETWEEN 1 AND 50
Your query is going to fail in SQL Server regardless of the row_number() call. The * returns all columns, including a.id and b.id. These both have the same name. This is fine for a query, but for a subquery, all columns need distinct names.
You can use row_number() for an arbitrary ordering by using a "subquery with constant" in the order by clause:
SELECT * FROM
(SELECT ROW_NUMBER() OVER (ORDER BY (select NULL)) AS ROW_NUMBER, *
FROM table1 a
LEFT JOIN table2 b
ON a.ID = b.ID) x
WHERE ROW_NUMBER BETWEEN 1 AND 50 ;
This removes the dependency on the underlying column name (assuming none are named ROW_NUMBER).
Try this sql. It should work.
SELECT * FROM
(SELECT ROW_NUMBER() OVER (ORDER BY a.Test) AS ROW_NUMBER, a.*,b.*
FROM table1 a
LEFT JOIN table2 b
ON a.ID = b.ID) x
WHERE ROW_NUMBER BETWEEN 1 AND 50
I have a large table but for the purposes of this question, let's assume I have the follwoing column strucure:
I'd like to have a Where statement that returns only rows where the e-mail address is distinct in that particular column.
Thoughts?
SELECT BillingEMail
FROM tableName
GROUP BY BillingEMail
HAVING COUNT(BillingEMail) = 1
OR HAVING COUNT(*) = 1
SQLFiddle Demo
I don't know what RDBMS you are using (the reason why i can't introduce of using analytical functions) but you can do this by joining with a subquery if you want to get all columns
SELECT a.*
FROM tableName a
INNER JOIN
(
SELECT BillingEMail
FROM tableName
GROUP BY BillingEMail
HAVING COUNT(BillingEMail) = 1
)b ON a.BillingEMail = b.BillingEMail
SQLFIddle Demo
In most databases, you can do this
select t.AccountId, t.BillingEmail
from (select t.*, count(*) over (partition by BillingEmail) as cnt
from t
) t
where cnt = 1
The advantage of this approach is that you can get as many columns as you like from the table.
I prefer JW's approach, but here is another one using NOT EXISTS.
SELECT AccountID, [Billing Email]
FROM table t1
WHERE NOT EXISTS (
-- Make sure that no other row contains the same
-- email, but a different Account ID.
SELECT 1
FROM table t2
WHERE t1.[Billing Email] = t2.[Billing Email]
AND t1.AccountID <> t2.AccountID
)