I want to fetch data from the database in my custom sequence.
For example if the query is;
SQL>Select * from table1 where id in(5,3,4)
So expected result would be.
Id | Name
----------
5 | John
3 | David
4 | Rock
but data is displaying in following order:
Id | Name
----------
3 | David
4 | Rock
5 | John
Can anyone help me to achieve this result?
The where clause is not relevant to the order of the results.
You can use "order by XXX" to arrange results by specific column/s,
but as I can see in your example it is not ordered by id or name.
So... I would suggest to add another column named "position" or "pos" and it will contain an integer with the desired order, than simple query with order by that column.
select *
from table1
where id in(5,3,4)
order by position
check this, it will give your wanted order
Select * from table1 where id=5
Union all
Select * from table1 where id=3
union all
Select * from table1 where id=4
Related
I realize that this has probably been asked a billion times, and I could swear I've done this in the past, but tonight I've got brain block or something and can't figure it out...
I have a database table ("t1") where I need to be able to retrieve only the first row where a particular value appears in a particular column.
Here's a sample of the data:
id | qID | Name
---------------------
1 | 1 | Bob
2 | 3 | Fred
3 | 1 | George
4 | 1 | Jack
What I want as a result is:
id | qID | Name
---------------------
1 | 1 | Bob
2 | 3 | Fred
The only column I actually need to get out of the query is the first one, but that's not where the duplicates need to be eliminated, and I thought it might be confusing not to show the entire row.
I've tried using this:
select id, qID, ROW_NUMBER() over(partition by qID order by qID) as zxy
from t1 where zxy = 1
But it gives me this error:
Msg 207, Level 16, State 1, Line 14
Invalid column name 'zxy'.
If I remove the where part of the query, the rest of it works fine. I've tried different variable names, using single or double quotes around 'zxy' but it seems to make no difference. And try as I might, I can't find the part of the SQL Server documentation where it discusses assigning a variable name to an expression, as in the "as zxy" part of the above query... if anybody has a link for that, that's quite useful.
Needless to say, I've tried other variable names besides "zxy" but that makes no difference.
Help!
WHERE clause is applied earlier in the process than SELECT. Therefore the calculated column zxy is not available in WHERE. In order to achieve your goal you need to put your original query in a subquery or CTE.
select id, qid
from
(
select id, qID, ROW_NUMBER() over(partition by qID order by qID) as zxy
from t1
) q
where zxy = 1
Output:
| id | qid |
|----|-----|
| 1 | 1 |
| 2 | 3 |
Here is SQLFiddle demo
Logical Processing Order of the SELECT statement
1 FROM
2 ON
3 JOIN
4 WHERE
5 GROUP BY
6 WITH CUBE or WITH ROLLUP
7 HAVING
8 SELECT
9 DISTINCT
10 ORDER BY
11 TOP
Where Clause Execute Before Select Clause so You can not find ZXY in Where cluase
with cte as
(
select id, qID, ROW_NUMBER() over(partition by qID order by qID) as zxy
from t1
)
select * from cte where zxy = 1
Here is my blog it might help you http://sqlearth.blogspot.in/2015/05/how-sql-select-statement-logically-works.html
I want my query to return the rows of a table in groups where a column contains specific values. After I got the rows ordered in the groups I want to be able to order them by name.
Example Table
- Id - Name - Group
- 1 George Group_2_1
- 2 Alfred Group_2_2
- 3 Eric Group_3
- 4 Mary Group_1_2
- 5 Jon Group_1_1
I want them ordered by their group and after that ordered by their name
- Id - Name - Group
- 1 Jon Group_1_1
- 2 Mary Group_1_2
- 3 Alfred Group_2_2
- 4 George Group_2_1
- 5 Eric Group_3
I found this SQL-Query-Snippet
ORDER BY CASE WHEN Group LIKE '%Group_1%' THEN 1 ELSE 2 END, Group
but it is not enough. The result is only grouped by the first group (obviously) but I can't extend it to order the second group because it is in the same column.
Please don't get confused by the example.
I just want to be able to group certain rows and put them in front of the results. I want a result that has all rows containing group 1 in the top, containing group 2 in the middle and containing group 3 in the bottom.
The values are not "Group_1_1" or something like that. They are just some strings and I want certain strings to be always in the first row (group 1) and some always below group 1
The problem here seems to be that some of your group names have an extra underscore, otherwise you could just order by the Group and all would be good. You could probably do something like this to work around this?
WITH Data AS (
SELECT 'Group1_1' AS Value
UNION
SELECT 'Group_3_2' AS Value
UNION
SELECT 'Group_2_2' AS Value
UNION
SELECT 'Group_3_1' AS Value
)
SELECT * FROM Data ORDER BY CASE WHEN Value LIKE 'Group_%' THEN SUBSTRING(Value, 7, 10) ELSE SUBSTRING(Value, 6, 10) END;
Results:
Value
Group1_1
Group_2_2
Group_3_1
Group_3_2
---- EDIT ----
Okay, seeing as your example isn't really an "example" it sounds like you are going to need a really, REALLY long case statement. You could do something like this (using the original Group_1_1, Group_2_2 codes) that would extend to different values. The key is that a CASE statement works from left to right and a value is assigned to the first case that matches:
ORDER BY
CASE
WHEN [Group] = 'Group_1_1' THEN 1
WHEN [Group] = 'Group_1_2' THEN 2
WHEN [Group] LIKE 'Group_1_%' THEN 3
WHEN [Group] = 'Group_2_1' THEN 4
WHEN [Group] = 'Group_2_2' THEN 5
WHEN [Group] LIKE 'Group_2_%' THEN 6
etc.
END;
Obviously that's very generic and depends on what the actual values are in your database.
Edits for mssql
If there is ANY instance of 3 underscores then the following simply won't work. However if there is the possibility of Group_12_6 or Group_21_1 then this approach may be worth trying.
It removes Group_ or Group from the string, leaving 1_1 or 12_6 or 21_1 then it replaces the remaining underscore with . giving 1.1 or 12.6 or 21.1 and casts this to decimal.
All utterly dependent of the consistency of those group names.
SELECT
id
, name
, [Group]
FROM YourData
ORDER BY
CAST(REPLACE(REPLACE(REPLACE([Group], 'Group_', ''), 'Group', ''), '_', '.') AS decimal(12,3))
, name
I'm really hoping you do not have a column called [Group] but if you do it has to be referenced as [Group] or "Group". Test result:
| ID | NAME | GROUP |
|----|--------|-----------|
| 1 | Jon | Group_1_1 |
| 2 | Mary | Group_1_2 |
| 4 | George | Group_2_1 |
| 3 | Alfred | Group_2_2 |
| 5 | Eric | Group_3 |
see http://sqlfiddle.com/#!3/e95b07/1
I have a question about SQL in parallel queries. For example, suppose that I have this query:
INSERT INTO tblExample (num) VALUES (1), (2)
And this query:
INSERT INTO tblExample (num) VALUES (3)
The final table should looked like this:
num
---
1
2
3
But I wonder if there is an option that those two queries will run in parallel and the final table will be looked like this:
num
---
1
3
2
Someone know the answer?
Thanks in advance!
There is no order in sql. You can sort your queries by adding an ORDER BY clause
SELECT * FROM tblExample ORDER BY num
Or you could add a timestamp column to the table and order by that.
How your table "looks" depends on how you asked for it (in the SELECT statement). Without an ORDER BY clause, the order of your table is undefined:
ORDER BY is the only way to sort the rows in the result set. Without this clause, the relational database system may return the rows in any order. If an ordering is required, the ORDER BY must be provided in the SELECT statement sent by the application.
For example:
SELECT num FROM tblExample ORDER BY num ASC
1
2
3
SELECT num FROM tblExample ORDER BY num DESC
3
2
1
If you want to order your columns manually, you can add a new column and sort on it:
+-----+-------+
| num | order |
+-----+-------+
| 1 | 1 |
| 2 | 3 |
| 3 | 2 |
+-----+-------+
SELECT num FROM tblExample ORDER BY order ASC
1
3
2
There are ton's of listings on how to find duplicate rows, and remove them, or list out the duplicates. In the masses of responses i've tried searching through on here those are the only responses i've found. I figured I would just put up my question since its been an hour and still no luck.
This is the example data I have
Table Name: Customers
_____________________________
ID | CompanyName
--------------
1 | Joes
2 | Wendys
3 | Kellys
4 | Ricks
5 | Wendys
6 | Kellys
7 | Kellys
I need to be able to find all the duplicates in this table, then put the results into another table that lists what the company name is, and how many duplicates it found.
For example the above table I should have a new table that says something like
Table Name: CustomerTotals
_______________________________
ID | CompanyName | Totals
-------------------------------
1 | Joes | 1
2 | Wendys | 2
3 | Kellys | 3
4 | Ricks | 1
-----EDIT Added after 2 responses, ran into another question------
Thanks for the responses! What about the opposite? say i only want to add items to a new table "UniqueCustomers" from the Customers table that doesn't exist in CustomerTotals table?
Try this :
INSERT INTO CustomerTotals
(CompanyName, Totals)
SELECT CompanyName, COUNT(*)
FROM Customer
GROUP BY CompanyName
Use an identity column for the ID field.
for get the duplicates, you can do
Insert into CustomerTotals (Id, CompanyName, Totals)
Select min(Id), CompanyName, count(*) From Customers
group by CompanyName
there you got the results, conserving the minimun id for each company name(if you really need the first id from your original table, as I see in the results).
If not, you can use an Identity Column
If you only want the duplicates to be inserted into the second table, use this:
INSERT INTO CustomerTotals
(CompanyName, Totals)
SELECT CompanyName, COUNT(*)
FROM Customer
GROUP BY CompanyName
HAVING Count(*) > 1
The above examples are fine. But you should use count(1) instead of count(*) to improve performance.
Read this question.
I think below script is simplest...
SELECT CompanyName, COUNT(*) AS Total
INTO #tempTable
FROM Customer
GROUP BY CompanyName
HAVING Count(*) > 1
I have a table for the link/relationship between two other tables, a table of customers and a table of groups. a group is made up of one or more customers. The link table is like
APP_ID | GROUP_ID | CUSTOMER_ID
1 | 1 | 123
1 | 1 | 124
1 | 1 | 125
1 | 2 | 123
1 | 2 | 125
2 | 3 | 123
3 | 1 | 123
3 | 1 | 124
3 | 1 | 125
I now have a need, given a list of customer IDs to be able to get the group ID for that list of customer IDs. Group ID may not be unique, the same group ID will contain the same list of customer IDs but this group may exist in more than one app_id.
I'm thinking that
SELECT APP_ID, GROUP_ID, COUNT(CUSTOMER_ID) AS COUNT
FROM GROUP_CUST_REL
WHERE CUSTOMER_ID IN ( <list of ids> )
GROUP BY APP_ID, GROUP_ID
HAVING COUNT(CUSTOMER_ID) = <number of ids in list>
will return me all of the group IDs that contain all of the customer ids in the given list and only those group ids. So for a list of (123,125) only group id 2 would be returned from the above example
I will then have to link with the app table to use its created timestamp to identify the most recent application that the group existed in so that I can then pull the correct/most up to date info from the group table.
Does anyone have any thoughts on whether this is the most efficient way to do this? If there is another quicker/cleaner way I'd appreciate your thoughts.
This smells like a division:
Division sample
Other related stack overflow question
Taking a look at the provided links you'll see the solution to similar issues from relational alegebra's point of view, doesn't seem to be quicker and arguably cleaner.
I didn't look at your solution at first, and when I solved this I turned out to have solved this the same way you did.
Actually, I thought this:
<number of ids in list>
Could be turned into something like this (so that you don't need the extra parameter):
select count(*) from (<list of ids>) as t
But clearly, I was wrong. I'd stay with your current solution if I were you.