There is a similar question which answer this for a known number of columns and only a single selection column. But the problem here is that
I have no knowledge of columns (count, type) of a specified SQL query and also I want to blank for all columns not a single column.
For example lets say I have following query.
Select * from View1
Result :
Column(1) Column(2) Column(..) Column(N)
1 A Sales 1500
2 C Sales 2500
3 C Sales 2500
4 A Development 2500
Expected result :
Column(1) Column(2) Column(..) Column(N)
1 A Sales 1500
2 C 2500
3
4 A Development
Pseudo SQL Query :
EXEC proc_blank_query_result 'Select * from View1'
If you're in SQL Server 2012 or newer, you can do this with lag, something like this:
select
nullif(column1, lag(column1) over (order by yourorderbyclause)) as column1,
nullif(column2, lag(column2) over (order by yourorderbyclause)) as column2,
...
from
View1
To make it dynamic, well then you have to parse a lot of metadata from the query. Using sp_describe_first_result_set might be a good idea, or use select into a temp. table and parse the columns of it.
Related
I have some data like this as shown below:
Acc_Id || Row_No
1 1
2 1
2 2
2 3
3 1
3 2
3 3
3 4
and I need a query to get the results as shown below:
Acc_Id || Row_No
1 1
2 3
3 4
Please consider that I'm a beginner in SQL.
I assume you want the Count of the row
SELECT Acc_Id, COUNT(*)
FROM Table
GROUP BY Acc_Id
Try this:
select Acc_Id, MAX(Row_No)
from table
group by Acc_Id
As a beginner then this is your first exposure to aggregation and grouping. You may want to look at the documentation on group by now that this problem has motivated your interest in a solutions. Grouping operates by looking at rows with common column values, that you specify, and collapsing them into a single row which represents the group. In your case values in Acc_Id are the names for your groups.
The other answers are both correct in the the final two columns are going to be equivalent with your data.
select Acc_Id, count(*), max(Row_No)
from T
group by Acc_Id;
If you have gaps in the numbering then they won't be the same. You'll have to decide whether you're actually looking for a count of rows of a maximum of a value within a column. At this point you can also consider a number of other aggregate functions that will be useful to you in the future. (Note that the actual values here are pretty much meaningless in this context.)
select Acc_Id, min(Row_No), sum(Row_No), avg(Row_No)
from T
group by Acc_Id;
I'm trying to add a column which calculates percentages of different products in MS Access Query. Basically, this is the structure of the query that I'm trying to reach:
Product |
Total |
Percentage
Prod1 |
15 |
21.13%
Prod2 |
23 |
32.39%
Prod3 |
33 |
46.48%
Product |
71 |
100%
The formula for finding the percent I use is: ([Total Q of a Product]/[Totals of all Products])*100, but when I try to use the expression builder (since my SQL skills are basic) in MS Access to calculate it..
= [CountOfProcuts] / Sum([CountOfProducts])
..I receive an error message "Cannot have aggregate function in GROUP BY clause.. (and the expression goes here)". I also tried the option with two queries: one that calculates only the totals and another that use the first one to calculate the percentages, but the result was the same.
I'll be grateful if someone can help me with this.
You can get all but the last row of your desired output with this query.
SELECT
y.Product,
y.Total,
Format((y.Total/sub.SumOfTotal),'#.##%') AS Percentage
FROM
YourTable AS y,
(
SELECT Sum(Total) AS SumOfTotal
FROM YourTable
) AS sub;
Since that query does not include a JOIN or WHERE condition, it returns a cross join between the table and the single row of the subquery.
If you need the last row from your question example, you can UNION the query with another which returns the fabricated row you want. In this example, I used a custom Dual table which is designed to always contain one and only one row. But you could substitute another table or query which returns a single row.
SELECT
y.Product,
y.Total,
Format((y.Total/sub.SumOfTotal),'#.##%') AS Percentage
FROM
YourTable AS y,
(
SELECT Sum(Total) AS SumOfTotal
FROM YourTable
) AS sub
UNION ALL
SELECT
'Product',
DSum('Total', 'YourTable'),
'100%'
FROM Dual;
I work with Databases not extensively but to the point where I can write Selects, update's ,small joins etc..
I can get my work done with my current knowledge. I have encountered some difficulty while trying to complete a task, I got the task completed but would like to understand why some of the SQL's that I have written in process did not work.
Task at hand: I have a table "TESTTABLE" that has 5 columns and the 6th is the sum of these 5 columns.
Currently table looks like below:
ID NAME SUB1 SUB2 SUB3 SUB4 SUB5 TOTAL
1 VA 10 20 30 40 50
2 MI 20 40 60 80 10
3 NC 10 30 50 70 90
4 SC 10 20 30 40 50
5 WA 20 40 60 80 15
the last column 'Total' is currently empty.
Now,I need to update the total column in the table with the sum(sub1+sub2=sub3+sub4+sub5).
In this process I have written the following SQL's and it did work, would like to understand the difference.
Attempt1:
UPDATE TESTTABLE T
SET Total =
SELECT (sub1+sub2+sub3+sub4+sub5)
FROM TESTTABLE TB
WHERE T.ID = TB.ID);
Error encountered:--ERROR: (2) This form of correlated query is not supported - consider rewriting;
Attempt2:
CREATE TABLE TEMP_TESTTABLE AS( SELECT ID, SUM(sub1+sub2+sub3+sub4+sub5) AS SUB_TOTAL FROM TESTTABLE )
UPDATE TESTTABLE A
SET TOTAL =
(SELECT SUB_TOTAL
FROM TEMP_TESTTABLE B
WHERE B.ID=A.ID);
ERROR encountered: ERROR: (2) This form of correlated query is not supported - consider rewriting
Attempt3:
UPDATE TESTTABLE
SET TOTAL = SUM(sub1+sub2+sub3+sub4+sub5);
ERROR encountered: ERROR: Aggregate functions not allowed in the set list of an UPDATE statement
Attempt4- Successful one;
UPDATE TESTTABLE A
SET TOTAL = B.SUB_TOTAL FROM TEMP_TESTTABLE B
WHERE A.ID=B.ID
Attempt 4 worked for me by using the temp table created in attempt2 [TEMP_TESTTABLE].
I need some detail explanation, and appreciate if anyone can provide me and let me know how my attempt4 is different than 1,2,3.
Help is greatly appreciated.
Thanks,
Attempt1 failed because subqueries should be enclosed in parentheses.
UPDATE TESTTABLE T
SET Total =
(SELECT (sub1+sub2+sub3+sub4+sub5)
FROM TESTTABLE TB
WHERE T.ID = TB.ID);
Attempt2 failed because SUM() function is aggregate function, to sum values from multiple rows, not to sum values from multiple columns in one row.
You should redefine the column as a computed column, like this
Alter table TESTTABLE
add column Total as sub1+sub2+sub3+sub4+sub5
This is the cannonical Soluion.
UPDATE
TESTTABLE
SET
Total = (sub1+sub2+sub3+sub4+sub5)
The reason the others failed is that you where doing subselects that returned multiple rows. You didn't tell the UPDATE how the different rows mapped from the select to the UPDATE.
In this version you are making it simple - one table - on each row set a value on that row based on the data in that row.
In your final version you're doing the same but in a redundant way (extra join that does nothing).
I need to show more than one result from each field in a table. I need to do this with only one SQL sentence, I don´t want to use a Cursor.
This seems silly, but the number of rows may vary for each item. I need this to print afterwards this information as a Crystal Report detail.
Suppose I have this table:
idItem Cantidad <more fields>
-------- -----------
1000 3
2000 2
3000 5
4000 1
I need this result, using one only SQL Sentence:
1000
1000
1000
2000
2000
3000
3000
3000
3000
3000
4000
where each idItem has Cantidad rows.
Any ideas?
It seems like something that should be handled in the UI (or the report). I don't know Crystal Reports well enough to make a suggestion there. If you really, truly need to do it in SQL, then you can use a Numbers table (or something similar):
SELECT
idItem
FROM
Some_Table ST
INNER JOIN Numbers N ON
N.number > 0 AND
N.number <= ST.cantidad
You can replace the Numbers table with a subquery or function or whatever other method you want to generate a result set of numbers that is at least large enough to cover your largest cantidad.
Check out UNPIVOT (MSDN)
Another example
If you use a "numbers" table that is useful for this and many similar purposes, you can use the following SQL:
select t.idItem
from myTable t
join numbers n on n.num between 1 and t.Cantidad
order by t.idTtem
The numbers table should just contain all integer numbers from 0 or 1 up to a number big enough so that Cantidad never exceeds it.
As others have said, you need a Numbers or Tally table which is just a sequential list of integers. However, if you knew that Cantidad was never going to be larger than five for example, you can do something like:
Select idItem
From Table
Join (
Select 1 As Value
Union All Select 2
Union All Select 3
Union All Select 4
Union All Select 5
) As Numbers
On Numbers.Value <= Table.Cantidad
If you are using SQL Server 2005, you can use a CTE to do:
With Numbers As
(
Select 1 As Value
Union All
Select N.Value + 1
From Numbers As N
)
Select idItem
From Table
Join Numbers As N
On N.Value <= Table.Cantidad
Option (MaxRecursion 0);
I have a table with columns like (in sql server 2000)
MailCode Mode Name Group
-------- ----- --------- -------
1 1 abc 0
1 1 def 0
1 1 qwe 1
2 2 aaw 0
2 2 aad 0
I want to group the Name field based on the rest of the fileds so that the result looks like this (there should be only one unique mailCode, Mode and group combination)
MailCode Mode Names Group
--------- ------ ------------ -------
1 1 abc, def 0
1 1 qwe 1
2 2 aaw, aad 0
How can I create the sql query for this?
I had a similar problem where I had to concatenate a field in the select, my solution at the time was to create a procedure that returned the result and called it like this
select x as field1, y as field2, dbo.procedure as field3
SQL Server 2000 solution
Luckily, COALESCE is supported in 2000, so you can use the COALESCE trick to create a comma delimited list of values, demonstrated in this link. Because of the variable usage, you'll need to create a function/procedure and call it within the main query. Basically, just replace the STUFF() in the query below with the function call.
SQL Server 2005+ solution:
SELECT x.mailcode,
x.mode,
STUFF((SELECT y.name
FROM TABLE y
WHERE y.mailcode = x.mailcode
AND y.mode = x.mode
AND y.gropu = x.group
GROUP BY y.mailcode, y.mode, y.group
FOR XML PATH(', ')), 1, 1, '') AS name,
x.group
FROM TABLE x
GROUP BY x.mailcode, x.mode, x.group
I can't think of a simple query that will get the result you're looking for, but some logic along these lines should get you where you want:
1) Loop through distinct MailCode, Mode, Group Rows
A) select all names in group
A.1) Loop through names
A.2) Concatenate them together into temp variable
B) insert all data (MailCode, Mode, Group, temp variable) into temp table
Fair waring, looping in SQL tends to have a huge performance hit when it comes to large datasets. I unfortunately don't know a better way to do it.