Aim: Using a Query - Delete all customers with no Assets
I have 2 tables. I want to delete all the rows where my count = 0:
My condition
if (SELECT COUNT(*) FROM Asset_Table WHERE Customer_ID='myString' ==0){
Delete row from Account_table
}
Accounts_Table :
CustomerID | Customer_Name | Onwner
-------------------------------------------------------------
123 | Jake | someowner1
124 | Ralph | someowner2
... | .... | ....
Asset_Table:
AssetINDEX | Customer_ID | Serial_ID |
-------------------------------------------------
5564 | 123 | xyz
5565 | 128 | xyz1
.... | ... | xyz2
Expected Result
Accounts_Table :
CustomerID | Customer_Name | Onwner
-------------------------------------------------------------
123 | Jake | someowner1
... | .... | ....
Asset_Table:
AssetINDEX | Customer_ID | Serial_ID |
-------------------------------------------------
5564 | 123 | xyz
.... | ... | xyz2
It appears in the "results" you gave in your question that you would like the data to be cleaned both ways. So that the only records remaining have references in both tables. To do this you need two statements and you can use the EXISTS clause.
DELETE FROM Accounts_Table
WHERE NOT EXISTS (SELECT CustomerID FROM Asset_Table WHERE Accounts_Table.CustomerID
= Asset_Table.Customer_ID)
DELETE FROM Asset_Table
WHERE NOT EXISTS (SELECT AssetINDEX FROM Accounts_Table where Asset_Table.Customer_ID
= Accounts_Table.CustomerID)
Delete all customers with no Assets
You can use exists to verify not existing rows in Asset_Table:
delete from Account_table AT
where not exists (select AssetINDEX from Asset_Table
where Customer_ID = AT.CustomerID)
Below query should work;
delete from Accounts_Table where CustomerID not in (select Customer_ID from Asset_Table )
DELETE C FROM
Account_table AS C
WHERE
NOT EXISTS (
SELECT
'the customer does not have any asset'
FROM
Asset_Table AS A
WHERE
A.Customer_ID = C.Customer_ID)
Related
I have a table as below
I want output like below
This means I have few predefined pairs, example
if one employee is coming from both HR_INTERNAL and HR_EXTERNAL, take only that record which is from HR_INTERNAL
if one employee is coming from both SALES_INTERNAL and SALES_EXTERNAL, take only that record which is from SALES_INTERNAL
etc.
Is there a way to achieve this?
I used ROW_NUMBER to rank
ROW_NUMBER() OVER(PARTITION BY "EMPID" ORDER BY SOURCESYSTEM ASC) AS RANK_GID
I just put them on a table like this:
create or replace table predefined_pairs ( pairs ARRAY );
insert into predefined_pairs select [ 'HR_INTERNAL', 'HR_EXTERNAL' ] ;
insert into predefined_pairs select [ 'SALES_INTERNAL', 'SALES_EXTERNAL' ] ;
Then I use the following query to produce the output you wanted:
select s.sourcesystem, s.empid,
CASE WHEN COUNT(1) OVER(PARTITION BY EMPID) = 1 THEN 'ValidRecord'
WHEN p.pairs[0] IS NULL THEN 'ValidRecord'
WHEN p.pairs[0] = s.sourcesystem THEN 'ValidRecord'
ELSE 'InvalidRecord'
END RecordValidity
from source s
left join predefined_pairs p on array_contains( s.sourcesystem::VARIANT, p.pairs ) ;
+-------------------+--------+----------------+
| SOURCESYSTEM | EMPID | RECORDVALIDITY |
+-------------------+--------+----------------+
| HR_INTERNAL | EMP001 | ValidRecord |
| HR_EXTERNAL | EMP001 | InvalidRecord |
| SALES_INTERNAL | EMP002 | ValidRecord |
| SALES_EXTERNAL | EMP002 | InvalidRecord |
| HR_EXTERNAL | EMP004 | ValidRecord |
| SALES_INTERNAL | EMP005 | ValidRecord |
| PURCHASE_INTERNAL | EMP003 | ValidRecord |
+-------------------+--------+----------------+
Let's say I have a table with many columns like col1, col2, col3, id, variantId, col4, col5 etc
However I am only interested in id, variantId which look like this:
+----------+-----------+
| id | variantId |
+----------+-----------+
| a | 11 |
| a | 12 |
| b | 31 |
| c | 41 |
| c | 54 |
| d | abc |
| e | xyz |
| e | xyz |
+----------+-----------+
I need distinct ids which having count of distinct variantId more than once
In this case I would only get a and c
You can use group by and having:
select id
from t
group by id
having min(variant_id) <> max(variant_id);
You can also use:
having count(distinct variant_id) > 1
Try with group by having clause
select id
from table
group by id
having count(distinct variant_id) > 1
You can do it more efficiently with EXISTS:
select distinct t.id
from tablename t
where exists (
select 1 from tablename
where id = t.id and variantid <> t.variantid
)
Let's say we have this and want to see all Tasks, that havent been done yet and an additional column showing how many open Tasks there are left for this customer.
I have a table like this in my database:
+------------+--------------------------+-------+
| CustomerID | Task | Done |
+------------+--------------------------+-------+
| 1 | CleanRoom | False |
| 1 | Cleandishes | True |
| 1 | WashClothes | False |
| 2 | TakeDogsOut | True |
| 2 | PlayWithKids | True |
| 3 | HaveFunWithMrSamplesWife | True |
| 3 | CleanMrSamplesCar | False |
+------------+--------------------------+-------+
I need this as returned table:
+------------+-------------------+-------------+
| CustomerID | Task | DoneOverAll |
+------------+-------------------+-------------+
| 1 | CleanRoom | 2 |
| 1 | WashClothes | 2 |
| 3 | CleanMrSamplesCar | 1 |
+------------+-------------------+-------------+
Perfect return table would be like this, but I can do that myself when I have the one above:
About this a question; Doing this will probably be a String combination task. Should I do this on the Select statement, or would it be more advisable to do that in the final application on the client computer?
+------------+-------------------+-------------+
| CustomerID | Task | DoneOverAll |
+------------+-------------------+-------------+
| 1 | CleanRoom | 1/3 |
| 1 | WashClothes | 1/3 |
| 3 | CleanMrSamplesCar | 1/2 |
+------------+-------------------+-------------+
I know I could go like
SELECT
a.CustomerID,
a.Task,
(
Select count(*) from myTable where
customerID = a.CustomerID and
done = False
) as DoneOverAll
FROM myTable as a
WHERE Done = False
But I think that this is very ineffective, since it would execute a Select Count for each row in my table. Is there a way to achieve this with a JOIN using groupBy or something? I'm not into GroupBy commands yet.
Okay I should have tried first. Came up with the following;
Select count(*), CustomerID from myTable group by CustomerID
All I need to do now is to get this into a join.
Okay, got it. Sorry again for not trying first!
SELECT
a.CustomerID,
a.Task,
b.cnt
FROM myTable as a
LEFT JOIN (select count(*) AS cnt, CustomerID FROM myTable GROUP BY CustomerID) as b on a.CustomerID = B.CustomerID
WHERE Done = False
Question left;
Perfect return table would be like this, but I can do that myself when I have the one above:
About this a question; Doing this will probably be a String combination task. Should I do this on the Select statement, or would it be more advisable to do that in the final application on the client computer?
+------------+-------------------+-------------+
| CustomerID | Task | DoneOverAll |
+------------+-------------------+-------------+
| 1 | CleanRoom | 1/3 |
| 1 | WashClothes | 1/3 |
| 3 | CleanMrSamplesCar | 1/2 |
+------------+-------------------+-------------+
I'm not sure why Done = False, but this is your logic. :-)
Here's what I would do, without the LEFT JOIN.
SELECT
a.CustomerID,
a.Task,
SUM(CASE WHEN a.Done = 'False' THEN 1 ELSE 0 END) DoneOverAll,
SUM(Case WHEN a.Done = 'True' THEN 1 ELSE 0 END) NotDone
FROM myTable as a
Group By a.CustomerID, a.Task
Do calculate separately .
;with tempfalse as(
SELECT
a.CustomerID,
a.Task,
count(*) as DoneOverAll
FROM myTable as a
WHERE Done = False
group by a.CustomerID, a.Task
)
, temptrue (
SELECT
a.CustomerID,
a.Task,
count(*) as total
FROM myTable as a
group by a.CustomerID, a.Task
)
SELECT
a.CustomerID,
a.Task,
cast(NULLIF(DoneOverAll,0) as varchar (10) ) + '/' + cast(NULLIF(b.total,0) as varchar (10) )
from temptrue as a left join tempfalse b
on a.CustomerID =a.CustomerID and
a.Task = b.Task
I have table with Employees (tblEmployee):
| ID | Name |
| 1 | Smith |
| 2 | Black |
| 3 | Thompson |
And a table with Roles (tblRoles):
| ID | Name |
| 1 | Submitter |
| 2 | Receiver |
| 3 | Analyzer |
I have also a table with relations of Employees to their Roles with many to many relation type (tblEmployeeRoleRel):
| EmployeeID | RoleID |
| 1 | 1 |
| 1 | 2 |
| 2 | 1 |
| 2 | 2 |
| 2 | 3 |
| 3 | 3 |
I need to select ID, Name from tblEmployee that have exaclty the same set of roles from tblEmployeeRoleRel as has the Employee with ID = 1. How can I do it?
Use a where clause to limit the roles you're looking at to those of employeeID of 1 and use a having clause to make sure that the employee's role count matches that of employee1.
SELECT A.EmployeeID
FROM tblEmployeeRoleRel A
WHERE Exists (SELECT 1
FROM tblEmployeeRoleRel B
WHERE B.EmployeeID = 1
and B.RoleID = A.RoleID)
GROUP BY A.EmployeeID
HAVING count(A.RoleID) = (SELECT count(C.RoleID)
FROM tblEmployeeRoleRel C
WHERE EmployeeID = 1)
This assumes that employeeID and roleID are unique in tblEmployeeRoleRel otherwise we may have to distinct the roleID fields above.
Declare #EmployeeID int = 1 -- change this to whatever employee ID you like, or perhaps you'd pass an Employee ID to it in a stored procedure.
Select Distinct e.EmployeeID -- normally distinct would incur extra overhead, but in this case you only want the employee IDs. not using Distinct when an employee has multiple roles will give you multiple employee IDs.
from tblEmployeeRoleRel as E
where E.EmployeeID not in
(Select EmployeeID from tblEmployeeRoleRel where RoleID not in (Select RoleID from tblEmployeeRoleRel where Employee_ID = #EmployeeID))
and exists (Select EmployeeID from tblEmployeeRoleRel where EmployeeID = e.EmployeeID) -- removes any "null" matches.
and E.Employee_ID <> #Employee_ID -- this keeps the employee ID itself from matching.
I need to add the same string to the beginning of each record for a varchar column. How would I go about doing this?
So the contents in that column currently look like this:
| TableNames |
--------------
| Table1 |
| Table2 |
| Table3 |
| Table4 |
And I want them to be:
| TableNames |
--------------
| dbo.Table1 |
| dbo.Table2 |
| dbo.Table3 |
| dbo.Table4 |
You could update the table by using its own entry (TableNames column) like this:
update MyTable set TableNames = 'dbo.' + TableNames;
commit;
and commit is just to commit the execution result.