how to skip Numbers in Sql Server using Order by - sql-server

I have sql query which returns the following Result :
select * from Emp Order By EmpName asc
Result :
Empid EmpName
1 1
2 2
3 3
A ALL
N NOTALL
but I want output like below :
Empid EmpName
A ALL
N NOTALL
1 1
2 2
3 3
how can I achieve this...

Define a custom sort order either like this:
select *
from Emp
Order By
CASE WHEN IsNumeric(EmpName) = 1 then 0 else 1 end asc,
Empid
or by adding an explict SortOrder column to the table
[Note: ISNUMERIC returns 1 for some characters that are not
numbers, such as plus (+), minus (-), and valid currency symbols such
as the dollar sign ($). For a complete list of currency symbols, see
Using Monetary Data.]

Use a custom sorting logic in your ordering something like:
ORDER BY
CASE
WHEN EMPID = 'A' THEN 1
WHEN EMPID = 'N' THEN 2
ELSE CAST(EMPID AS INT) + 2
END
You could also use the ISNUMERIC function as described in Mitch Wheat's answer to avoid explicitly declaring the cases. However, in case you have a non-alphabetical order e.g. 'G' should appear before 'A', then it would be good to explicitly specify the values.

Related

Assign same value to every line where condition is met for one line using case logic

I'm looking to find all of the tracking numbers where one line meets a condition and then assign a value to every row of that tracking number. I'm currently doing this with case logic but only get halfway there without creating more statements. Looking for a clean single statement.
The sql below only gives me the the case value for the line where I'd want it for every line in the tracking number where it applied. I'd want it to assign that value to every row in the case statement.
select [Tracking_No] ,
CASE WHEN [Tracking_No] in
(Select distinct [Tracking_No] where ([Row_Value] like '%A%') Then '1'
WHEN [Tracking Number] in
(Select distinct [Tracking_No] where ([Row_Value] like '%B%') Then '2'
ELSE '' END as Description
from dwh.mytable
Looking for something similar to this:
Tracking_No
Row_Value
Description
10
B
1
10
C
1
10
A
1
11
Q
2
11
B
2
11
D
2
12
A
1
12
D
1
12
D
1
You could perhaps try a windowed aggregate here
select *,
case
when Min(Row_Value) over(partition by Tracking_No) like '%A%' then '1'
when Min(Row_Value) over(partition by Tracking_No) like '%B%' then '2'
end [Description]
from t;

SQL: Match two columns containing NULL values and strings and extract only the matching rows without NULL

I have a temp table FileTable as follows:
ID FileNameAct FileNameString
1 NULL SalesOrderTarget
2 NULL SalesTarget
3 InventoryMaterialTarget_20220414.xlsx NULL
4 InventoryTarget_20220414.xlsx NULL
5 SalesOrderTarget_20220412.xlsx NULL
6 SalesTarget_20220412.xlsx NULL
Objective: To match the string between FileNameAct and FileNameString and take out the rows that has very close match.
So the resultant table should look like below:
ID FileNameAct FileNameString
1 SalesOrderTarget_20220412.xlsx SalesOrderTarget
2 SalesTarget_20220412.xlsx SalesTarget
I am thinking in below line:
SELECT X.* FROM (SELECT FileNameAct, FileNameString,
CASE WHEN ISNULL(FileNameAct,'') LIKE '%'+ ISNULL(FileNameString,'') + '%' THEN 1 ELSE 0
END AS Flag
FROM #FileTable) X
WHERE X.Flag=1
Clearly, this would not give the correct result.
Can anybody share any thoughts?
You can use a self-join with conditions
Select
b.id,
a.FileNameAct,
b.FileNameString
From #FileTable a
Join #FileTable b
On a.FileNameAct
like concat(b.FileNameString,'%')
Where b.FileNameString is not null;

Data manipulation using SQL Server Substring so something else

I have a table A like this:
ID Col1
----------------------
1 xyz-abcccc
2 xyz-jkasdasd
3 abcds-asks
4 asdasdasda-as
I want to get output like this:
ID Col1
-------------
1 abcccc
2 jkasdasd
3 asks
4 as
I want get output where anything before the dash - is ignored.
Thanks
charindex() would be a good place to start. The only trick is add a dash within the charindex function as a fail-safe thus avoids throwing an error.
Example
Select ID
,Col1 = substring(Col1,charindex('-',col1+'-')+1,len(Col1))
from YourTable
Returns
ID Col1
1 abcccc
2 jkasdasd
3 asks
4 as
You can use a combination of RIGHT and CHARINDEX functions as well.
Query
select [ID],
case when [Col1] like '%-%' then right([Col1], charindex('-', reverse([Col1]), 1) - 1)
else [Col1] end as [new_col1]
from [your_table_name];

Get a count based on the row order

I have a table with this structure
Create Table Example (
[order] INT,
[typeID] INT
)
With this data:
order|type
1 7
2 11
3 11
4 18
5 5
6 19
7 5
8 5
9 3
10 11
11 11
12 3
I need to get the count of each type based on the order, something like:
type|count
7 1
11 **2**
18 1
5 1
19 1
5 **2**
3 1
11 **2**
3 1
Context
Lets say that this table is about houses, so I have a list houses in an order. So I have
Order 1: A red house
2: A white house
3: A white house
4: A red house
5: A blue house
6: A blue house
7: A white house
So I need to show that info condensed. I need to say:
I have 1 red house
Then I have 2 white houses
Then I have 1 red house
Then I have 2 blue houses
Then I have 1 white house
So the count is based on the order. The DENSE_RANK function would help me if I were able to reset the RANK when the partition changes.
So I have an answer, but I have to warn you it's probably going to get some raised eyebrows because of how it's done. It uses something known as a "Quirky Update". If you plan to implement this, please for the love of god read through the linked article and understand that this is an "undocumented hack" which needs to be implemented precisely to avoid unintended consequences.
If you have a tiny bit of data, I'd just do it row by agonizing row for simplicity and clarity. However if you have a lot of data and still need high performance, this might do.
Requirements
Table must have a clustered index in the order you want to progress in
Table must have no other indexes (these might cause SQL to read the data from another index which is not in the correct order, causing the quantum superposition of row order to come collapsing down).
Table must be completely locked down during the operation (tablockx)
Update must progress in serial fashion (maxdop 1)
What it does
You know how people tell you there is no implicit order to the data in a table? That's still true 99% of the time. Except we know that ultimately it HAS to be stored on disk in SOME order. And it's that order that we're exploiting here. By forcing a clustered index update and the fact that you can assign variables in the same update statement that columns are updated, you can effectively scroll through the data REALLY fast.
Let's set up the data:
if object_id('tempdb.dbo.#t') is not null drop table #t
create table #t
(
_order int primary key clustered,
_type int,
_grp int
)
insert into #t (_order, _type)
select 1,7
union all select 2,11
union all select 3,11
union all select 4,18
union all select 5,5
union all select 6,19
union all select 7,5
union all select 8,5
union all select 9,3
union all select 10,11
union all select 11,11
union all select 12,3
Here's the update statement. I'll walk through each of the components below
declare #Order int, #Type int, #Grp int
update #t with (tablockx)
set #Order = _order,
#Grp = case when _order = 1 then 1
when _type != #Type then #grp + 1
else #Grp
end,
#Type = _type,
_grp = #Grp
option (maxdop 1)
Update is performed with (tablockx). If you're working with a temp table, you know there's no contention on the table, but still it's a good habit to get into (if using this approach can even be considered a good habit to get into at all).
Set #Order = _order. This looks like a pointless statement, and it kind of is. However since _order is the primary key of the table, assigning that to a variable is what forces SQL to perform a clustered index update, which is crucial to this working
Populate an integer to represent the sequential groups you want. This is where the magic happens, and you have to think about it in terms of it scrolling through the table. When _order is 1 (the first row), just set the #Grp variable to 1. If, on any given row, the column value of _type differs from the variable value of #type, we increment the grouping variable. If the values are the same, we just stick with the #Grp we have from the previous row.
Update the #Type variable with the column _type's value. Note this HAS to come after the assignment of #Grp for it to have the correct value.
Finally, set _grp = #Grp. This is where the actual column value is updated with the results of step 3.
All this must be done with option (maxdop 1). This means the Maximum Degree of Parallelism is set to 1. In other words, SQL cannot do any task parallelization which might lead to the ordering being off.
Now it's just a matter of grouping by the _grp field. You'll have a unique _grp value for each consecutive batch of _type.
Conclusion
If this seems bananas and hacky, it is. As with all things, you need to take this with a grain of salt, and I'd recommend really playing around with the concept to fully understand it if you plan to implement it because I guarantee nobody else is going to know how to troubleshoot it if you get a call in the middle of the night that it's breaking.
This solution is using a recursive CTE and is relying on a gapless order value. If you don't have this, you can create it with ROW_NUMBER() on the fly:
DECLARE #mockup TABLE([order] INT,[type] INT);
INSERT INTO #mockup VALUES
(1,7)
,(2,11)
,(3,11)
,(4,18)
,(5,5)
,(6,19)
,(7,5)
,(8,5)
,(9,3)
,(10,11)
,(11,11)
,(12,3);
WITH recCTE AS
(
SELECT m.[order]
,m.[type]
,1 AS IncCounter
,1 AS [Rank]
FROM #mockup AS m
WHERE m.[order]=1
UNION ALL
SELECT m.[order]
,m.[type]
,CASE WHEN m.[type]=r.[type] THEN r.IncCounter+1 ELSE 1 END
,CASE WHEN m.[type]<>r.[type] THEN r.[Rank]+1 ELSE r.[Rank] END
FROM #mockup AS m
INNER JOIN recCTE AS r ON m.[order]=r.[order]+1
)
SELECT recCTE.[type]
,MAX(recCTE.[IncCounter])
,recCTE.[Rank]
FROM recCTE
GROUP BY recCTE.[type], recCTE.[Rank];
The recursion is traversing down the line increasing the counter if the type is unchanged and increasing the rank if the type is different.
The rest is a simple GROUP BY
I thought I'd post another approach I worked out, I think more along the lines of the dense_rank() work others were thinking about. The only thing this assumes is that _order is a sequential integer (i.e. no gaps).
Same data setup as before:
if object_id('tempdb.dbo.#t') is not null drop table #t
create table #t
(
_order int primary key clustered,
_type int,
_grp int
)
insert into #t (_order, _type)
select 1,7
union all select 2,11
union all select 3,11
union all select 4,18
union all select 5,5
union all select 6,19
union all select 7,5
union all select 8,5
union all select 9,3
union all select 10,11
union all select 11,11
union all select 12,3
What this approach does is row_number each _type so that regardless of where a _type exists, and how many times, the types will have a unique row_number in the order of the _order field. By subtracting that type-specific row number from the global row number (i.e. _order), you'll end up with groups. Here's the code for this one, then I'll walk through this as well.
;with tr as
(
select
-- Create an incrementing integer row_number over each _type (regardless of it's position in the sequence)
_type_rid = row_number() over (partition by _type order by _order),
-- This shows that on rows 6-8 (the transition between type 19 and 5), naively they're all assigned the same group
naive_type_rid = _order - row_number() over (partition by _type order by _order),
-- By adding a value to the type_rid which is a function of _type, those two values are distinct.
-- Originally I just added the value, but I think squaring it ensures that there can't ever be another gap of 1
true_type_rid = (_order - row_number() over (partition by _type order by _order)) + power(_type, 2),
_type,
_order
from #t
-- order by _order -- uncomment this if you want to run the inner select separately
)
select
_grp = dense_rank() over (order by max(_order)),
_type = max(_type)
from tr
group by true_type_rid
order by max(_order)
What's Going On
First things first; I didn't have to create a separate column in the src cte to return _type_rid. I did that mostly for troubleshooting and clarity. Secondly, I also didn't really have to do a second dense_rank on the final selection for the column _grp. I just did that so it matched exactly the results from my other approach.
Within each type, type_rid is unique, and increments by 1. _order also increments by one. So as long as a given type is chugging along, gapped by only 1, _order - _type_rid will be the same value. Let's look at a couple examples (This is the result of the src cte, ordered by _order):
_type_rid naive_type_rid true_type_rid _type _order
-------------------- -------------------- -------------------- ----------- -----------
1 8 17 3 9
2 10 19 3 12
1 4 29 5 5
2 5 30 5 7
3 5 30 5 8
1 0 49 7 1
1 1 122 11 2
2 1 122 11 3
3 7 128 11 10
4 7 128 11 11
1 3 327 18 4
1 5 366 19 6
First row, _order - _type_rid = 1 - 1 = 0. This assigns this row (type 7) to group 0
Second row, 2 - 1 = 1. This assigns type 11 to group 1
Third row, 3 - 2 = 1. This assigns the second sequential type 11 to group 1 also
Forth row, 4 - 1 = 3. This assigns type 18 to group 3
... and so forth.
The groups aren't sequential, but they ARE in the same order as _order which is the important part. You'll also notice I added the value of _type to that value as well. That's because when we hit some of the later rows, groups switched, but the sequence was still incremented by 1. By adding _type, we can differentiate those off-by-one values and still do it in the right order as well.
The final outer select from src orders by the max(_order) (in both my unnecessary dense_rank() _grp modification, and just the general result order).
Conclusion
This is still a little wonky, but definitely well within the bounds of "supported functionality". Given that I ran into one gotcha in there (the off-by-one thing), there might be others I haven't considered, so again, take that with a grain of salt, and do some testing.

SQL SELECT Ordering columns with Null Values

My question is similar to this one: How to display a table order by code (like 01, 02… then null columns)?, but for SQL Server.
In short, I have a SELECT statement, that returns the following:
ColumnA ColumnB
X NULL
Y 1
Z 2
..where the ordering is done by ColumnB.
How can we force the (columnB = NULL) type of rows to the bottom? ie, the expected result is this:
ColumnA ColumnB
Y 1
Z 2
X NULL
Thank you SOF community.
...or in order to avoid value clashing...
SELECT
ColumnA,
ColumnB
FROM YourTable
ORDER BY
CASE WHEN ColumnB IS NULL THEN 1 ELSE 0 END ASC,
ColumnB
You can also use isnull:
select * from thetable order by isnull(columnb, 99999)
isnull will replace null with the value you provide to it, so in this case, if the column is null, it will replace it with 99999. You can set the value to some big number so it will be at the bottom of the order.
hoping to help someone,
I just wanted to add that I have had a similiar issue, using row_number and partition by -
when it is zero put it at the end sort of thing
and I used the script below (partial view):
,T.MONTHS_TO_AUTOGROWTH
,the_closest_event=ROW_NUMBER() OVER (PARTITION BY SERVERID, DRIVE ORDER BY
CASE WHEN MONTHS_TO_AUTOGROWTH > 0 THEN MONTHS_TO_AUTOGROWTH ELSE 9999
END )
the result is ordered by MONTHS_TO_AUTOGROWTH but zero comes last

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