SQL Query - More options and suggestions apart from pivoting - sql

New to SQL please dont mind if this is a silly question..
My table looks like this
I want to send only one email to manager telling him that these employees in your group failed to fill timesheet.
currently i have pivoted the above table that looks like this
and sending emails by concatinating firstemp+secondemp+thirdemp+------
can this be done in any more easiest way..?

You can use CONCAT() function to retrieve a single row data in one column
SELECT M_EMAIL,
CONCAT(FIRSTEMP, SECONDEMP, THIRDEMP, FOURTHEMP, FIFTHEMP...)
FROM 'your_table';
CONCAT() replaces NULL values with an empty string.

Please don't pivot, as the concat is really ugly to maintain (and will break if a more capable manager pops up with more subordinates than your concat columns).
The syntax depends on what SQL server you use. For example, in MSSQL you could do this:
select manager, m_email, STRING_AGG(employee, ', ') as subordinates
from Employee
group by manager, m_email
This result has only 1 row per manager and fixed number of columns regardless how many subordinates the manager has:
manager | m_email | subordinates
----------------------------------
A | A#A.COM | b, D
D | D#D.COM | e, h
I | I#I.COM | j
Play with the example here: http://sqlfiddle.com/#!18/73bb5/5
Another option is just query relevant data to application layer and do the grouping there.

Related

Listing items within a category (SQL)

I have a data set like the following:
+-----------------+---------------------+
| job_code | job_title |
+-----------------+---------------------+
| finance_acct | Business Accountant |
| finance_manager | Business Manager |
| it_programmer | IT Programmer |
| it_manager | IT Manager |
+-----------------+---------------------+
etc.
I want to take all of the job titles that share the same first half of their job code and print them as a list. Like the following:
finance: Business Accountant, Business Manager
it: IT Programmer, IT Manager
How would I do so? I know how to use SUBSTR to pull the first part of the job code. Basically I can create the left column fine. I ran into a couple of problems though:
Using the GROUP BY command, I continually got ORA-00979 error ("not
a GROUP BY expression").
I can't figure out how to make the list delimited with commas. I
used CONCAT but even then you end up with a superfluous comma after
the last entry for a given line. I've seen some things online about
the STUFF command, but I know it's possible to do so without this.
Any tips? Thank you.
regexp_substr() comes to mind to extract the part you want from the job_code. The rest is just aggregation and listagg():
select regexp_substr(job_code, '[^_]+', 1, 1) as half_job_code,
listagg(job_title, ', ') within group (order by job_title) as job_titles
from t
group by regexp_substr(job_code, '[^_]+', 1, 1)
Try the listagg function. you can specify a delimited and group it based on the data you require.

SQL: Concatenate all fields matching a given key?

Suppose I have a SQL query like this:
SELECT
tickets.TicketNumber, history.remarks
FROM
AT_DeviceReplacement_Tickets tickets
INNER JOIN
AT_DeviceReplacement_Tickets_History history
ON tickets.TicketNumber = history.TicketNumber;
I get a table like this in repsonse:
ticketNumber | remarks
-------------+------------
1 | "Hello, there is a problem."
1 | "Did you check the power cable?
1 | "We plugged it in and now it works. Thank you!"
2 | "Hello, this is a new ticket."
Suppose that I want to write a query that will concatenate the remarks for each ticket and return a table like this:
ticketNumber | remarks
-------------+------------
1 | "Hello, there is a problem.Did you check the power cable?We plugged it in and now it works. Thank you!"
2 | "Hello, this is a new ticket."
Yes, in the real code, I've actually got these sorted by date, among other things, but just for the sake of discussion, how would I edit the above query to get the result I described?
Have a look at the following questions:
Can I Comma Delimit Multiple Rows Into One Column?
Is it possible to concatenate column values into a string using CTE?
The cleanest solution to this problem is DB dependent. Lentine's links show very ugly solutions for Oracle and SQL Server and a clean one for MySQL. The answer in PostgreSQL is also very short and easy.
SELECT ticket_number, string_agg(remarks, ', ')
FROM
AT_DeviceReplacement_Tickets tickets
INNER JOIN
AT_DeviceReplacement_Tickets_History history
ON tickets.Ticket_Number = history.Ticket_Number
GROUP BY tickets.ticket_number;
(Note you have both ticket_number and TicketNumber in your sample code.)
My guess is that Oracle and SQL Server either (1) have a similar aggregate function or (2) have the capability of defining your own aggregate functions. [For MySQL the equivalent aggregate is called GROUP_CONCAT.] What DB are you using?

Use Access SQL to do a grouped ranking

How do I rank salespeople by # customers grouped by department (with ties included)?
For example, given this table, I want to create the Rank column on the right. How should I do this in Access?
SalesPerson Dept #Customers Rank
Bill DeptA 20 1
Ted DeptA 30 2
Jane DeptA 40 3
Bill DeptB 50 1
Mary DeptB 60 2
I already know how to do a simple ranking with this SQL code. But I don't know how to rework this to accept grouping.
Select Count(*) from [Tbl] Where [#Customers] < [Tblx]![#Customers] )+1
Also, there's plenty of answers for this using SQL Server's Rank() function, but I need to do this in Access. Suggestions, please?
SELECT *, (select count(*) from tbl as tbl2 where
tbl.customers > tbl2.customers and tbl.dept = tbl2.dept) + 1 as rank from tbl
Just add the dept field to the subquery...
Great solution with subquery! Except for huge recordsets, the subquery solution gets very slow. Its better(quicker) to use a Self JOIN, look at the folowing solution: self join
SELECT tbl1.SalesPerson , count(*) AS Rank
FROM tbl AS tbl1 INNER JOIN tbl AS tbl2 ON tbl1.DEPT = tbl2.DEPT
AND tbl1.#Customers < tbl2.#Customers
GROUP BY tbl1.SalesPerson
I know this is an old thread. But since I spent a great deal of time on a very similar problem and was greatly helped by the former answers given here, I would like to share what I have found to be a MUCH faster way. (Beware, it is more complicated.)
First make another table called "Individualizer". This will have one field containing a list of numbers 1 through the-highest-rank-that-you-need.
Next create a VBA module and paste this into it:
'Global Declarations Section.
Option Explicit
Global Cntr
'*************************************************************
' Function: Qcntr()
'
' Purpose: This function will increment and return a dynamic
' counter. This function should be called from a query.
'*************************************************************
Function QCntr(x) As Long
Cntr = Cntr + 1
QCntr = Cntr
End Function
'**************************************************************
' Function: SetToZero()
'
' Purpose: This function will reset the global Cntr to 0. This
' function should be called each time before running a query
' containing the Qcntr() function.
'**************************************************************
Function SetToZero()
Cntr = 0
End Function
Save it as Module1.
Next, create Query1 like this:
SELECT Table1.Dept, Count(Table1.Salesperson) AS CountOfSalesperson
FROM Table1
GROUP BY Table1.Dept;
Create a MakeTable query called Query2 like this:
SELECT SetToZero() AS Expr1, QCntr([ID]) AS Rank, Query1.Dept,
Query1.CountOfSalesperson, Individualizer.ID
INTO Qtable1
FROM Query1
INNER JOIN Individualizer
ON Query1.CountOfSalesperson >= Individualizer.ID;
Create another MakeTable query called Query3 like this:
SELECT SetToZero() AS Expr1, QCntr([Identifier]) AS Rank,
[Salesperson] & [Dept] & [#Customers] AS Identifier, Table1.Salesperson,
Table1.Dept, Table1.[#Customers]
INTO Qtable2
FROM Table1;
If you have another field already that uniquely identifies every row you wouldn't need to create an Identifier field.
Run Query2 and Query3 to create the tables.
Create a fourth query called Query4 like this:
SELECT Qtable2.Salesperson, Qtable2.Dept, Qtable2.[#Customers], Qtable1.ID AS Rank
FROM Qtable1
INNER JOIN Qtable2 ON Qtable1.Rank = Qtable2.Rank;
Query4 returns the result you are looking for.
Practically, you would want to write a VBA function to run Query2 and Query3 and then call that function from a button placed in a convenient location.
Now I know this sounds ridiculously complicated for the example you gave. But in real life, I am sure your table is more complicated than this. Hopefully my examples can be applied to your actual situation. In my database with over 12,000 records this method is by FAR the fastest (as in: 6 seconds with 12,000 records compared to over 1 minute with 262 records ranked with the subquery method).
The real secret for me was the MakeTable query because this ranking method is useless unless you immediately output the results to a table. But, this does limit the situations that it can be applied to.
P.S. I forgot to mention that in my database I was not pulling results directly from a table. The records had already gone through a string of queries and multiple calculations before they needed to be ranked. This probably contributed greatly to the huge difference in speed between the two methods in my situation. If you are pulling records directly from a table, you might not notice nearly as big an improvement.
You need to do some math. I typically take advantage of the combination of a counter field and an "offset" field. You're aiming for a table which looks like this (#Customers isn't necessary, but will give you a visual that you're doing it properly):
SalesPerson Dept #Customers Ctr Offset
Bill DeptA 20 1 1
Ted DeptA 30 2 1
Jane DeptA 40 3 1
Bill DeptB 50 4 4
Mary DeptB 60 5 4
So, to give rank, you'd do [Ctr]-[Offset]+1 AS Rank
build a table with SalesPerson, Dept, Ctr, and Offset
insert into that table, ordered by Dept and #Customers (so that they're all sorted properly)
Update Offset to be the MIN(Ctr), grouping on Dept
Perform your math calculation to determine Rank
Clear out the table so you're ready to use it again next time.
To add to this and any other related Access Ranking or Rank Tie Breaker how-tos for other versions of Access, ranking should not be performed on crosstab queries if your FROM clause happens to NOT contain a table but a query that is either a crosstab query or a query that contains within it elsewhere a crosstab query.
The code referenced above where a SELECT statement within a SELECT statment is used (sub query),
"SELECT *, (select count(*) from tbl as tbl2 where tbl.customers > tbl2.customers and tbl.dept = tbl2.dept) + 1 as rank from tbl"
will not work and will always fail expressing a error on portion of the code where "tbl.customers > tbl2.customers" cannot be found.
In my situation on a past project, I was referencing a query instead of a table and within that query I had referenced a crosstab query thus failing and producing an error. I was able to resolve this by creating a table from the crosstab query first, and when I referenced the newly created table in the FROM clause, it started working for me.
So in final, normally you can reference a query or table in the FROM clause of the SELECT statement as what was shared previously above to do ranking, but be carefull as to if you are referencing a query instead of a table, that query must Not be a crosstab query or reference another query that is a crosstab query.
Hope this helps anyone else that may have had problems looking for a possible reason if you happen to reference the statements above and you are not referencing a table in your FROM clause within your own project. Also, performing subqueries on aliases with crosstab queries in Access probably isn't good idea or best practice either so stray away from that if/when possible.
If you found this useful, and wish that Access would allow the use of a scrolling mouse in a passthru query editor, give me a like please.
I normally pick tips and ideas from here and sometimes end up building amazing things from it!
Today, (well let’s say for the past one week), I have been tinkering with Ranking of data in Access and to the best of my ability, I did not anticipate what I was going to do something so complex as to take me a week to figure it out! I picked titbits from two main sites:
https://usefulgyaan.wordpress.com/2013/04/23/ranking-in-ms-access/ (seen that clever ‘>=’ part, and the self joins? Amazing… it helped me to build my solution from just one query, as opposed to the complex method suggested above by asonoftheMighty (not discrediting you… just didn’t want to try it for now; may be when I get to large data I might want to try that as well…)
Right here, from Paul Abott above ( ‘and tbl.dept = tbl2.dept’)… I was lost after ranking because I was placing AND YearID = 1, etc, then the ranking would end up happening only for sub-sets, you guessed right, when YearID = 1! But I had a lot of different scenarios…
Well, I gave that story partly to thank the contributors mentioned, because what I did is to me one of the most complex of the ranking that I think can help you in almost any situation, and since I benefited from others, I would like to share here what I hope may benefit others as well.
Forgive me that I am not able to post my table structures here, it is a lot of related tables. I will only post the query, so if you need to you may develop your tables to end up with that kind of query. But here is my scenario:
You have students in a school. They go through class 1 to 4, can either be in stream A or B, or none when the class is too small. They each take 4 exams (this part is not important now), so you get the total score for my case. That’s it. Huh??
Ok. Lets rank them this way:
We want to know the ranking of
• all students who ever passed through this school (best ever student)
• all students in a particular academic year (student of the year)
• students of a particular class (but remember a student will have passed through all classes, so basically his/her rank in each of those classes for the different years) this is the usual ranking that appears in report cards
• students in their streams (above comment applies)
• I would also like to know the population against which we ranked this student in each category
… all in one table/query. Now you get the point?
(I normally like to do as much of my 'programming' in the database/queries to give me visuals and to reduce the amount of code I will later have to right. I actually won't use this query in my application :), but it let's me know where and how to send my parameters to the query it came from, and what results to expect in my rdlc)
Don't you worry, here it is:
SELECT Sc.StudentID, Sc.StudentName, Sc.Mark,
(SELECT COUNT(Sch.Mark) FROM [StudentScoreRankTermQ] AS Sch WHERE (Sch.Mark >= Sc.Mark)) AS SchoolRank,
(SELECT Count(s.StudentID) FROM StudentScoreRankTermQ AS s) As SchoolTotal,
(SELECT COUNT(Yr.Mark) FROM [StudentScoreRankTermQ] AS Yr WHERE (Yr.Mark >= Sc.Mark) AND (Yr.YearID = Sc.YearID) ) AS YearRank,
(SELECT COUNT(StudentID) FROM StudentScoreRankTermQ AS Yt WHERE (Yt.YearID = Sc.YearID) ) AS YearTotal,
(SELECT COUNT(Cl.Mark) FROM [StudentScoreRankTermQ] AS Cl WHERE (Cl.Mark >= Sc.Mark) AND (Cl.YearID = Sc.YearID) AND (Cl.TermID = Sc.TermID) AND (Cl.ClassID=Sc.ClassID)) AS ClassRank,
(SELECT COUNT(StudentID) FROM StudentScoreRankTermQ AS C WHERE (C.YearID = Sc.YearID) AND (C.TermID = Sc.TermID) AND (C.ClassID = Sc.ClassID) ) AS ClassTotal,
(SELECT COUNT(Str.Mark) FROM [StudentScoreRankTermQ] AS Str WHERE (Str.Mark >= Sc.Mark) AND (Str.YearID = Sc.YearID) AND (Str.TermID = Sc.TermID) AND (Str.ClassID=Sc.ClassID) AND (Str.StreamID = Sc.StreamID) ) AS StreamRank,
(SELECT COUNT(StudentID) FROM StudentScoreRankTermQ AS St WHERE (St.YearID = Sc.YearID) AND (St.TermID = Sc.TermID) AND (St.ClassID = Sc.ClassID) AND (St.StreamID = Sc.StreamID) ) AS StreamTotal,
Sc.CalendarYear, Sc.Term, Sc.ClassNo, Sc.Stream, Sc.StreamID, Sc.YearID, Sc.TermID, Sc.ClassID
FROM StudentScoreRankTermQ AS Sc
ORDER BY Sc.Mark DESC;
You should get something like this:
+-----------+-------------+------+------------+-------------+----------+-----------+-----------+------------+------------+-------------+------+------+-------+--------+
| StudentID | StudentName | Mark | SchoolRank | SchoolTotal | YearRank | YearTotal | ClassRank | ClassTotal | StreamRank | StreamTotal | Year | Term | Class | Stream |
+-----------+-------------+------+------------+-------------+----------+-----------+-----------+------------+------------+-------------+------+------+-------+--------+
| 1 | Jane | 200 | 1 | 20 | 2 | 12 | 1 | 9 | 1 | 5 | 2017 | I | 2 | A |
| 2 | Tom | 199 | 2 | 20 | 1 | 12 | 3 | 9 | 1 | 4 | 2016 | I | 1 | B |
+-----------+-------------+------+------------+-------------+----------+-----------+-----------+------------+------------+-------------+------+------+-------+--------+
Use the separators | to reconstruct the result table
Just an idea about the tables, each student will be related to a class. Each class relates to years. Each stream relates to a class. Each term relates to a year. Each exam relates to a term and student and a class and a year; a student can be in class 1A in 2016 and moves on to class 2b in 2017, etc…
Let me also add that this a beta result, I have not tested it well enough and I do not yet have an opportunity to create a lot of data to see the performance. My first glance at it told me that it is good. So if you find reasons or alerts you want to point my way, please do so in comments so I may keep learning!

SQL: Select distinct based on regular expression

Basically, I'm dealing with a horribly set up table that I'd love to rebuild, but am not sure I can at this point.
So, the table is of addresses, and it has a ton of similar entries for the same address. But there are sometimes slight variations in the address (i.e., a room # is tacked on IN THE SAME COLUMN, ugh).
Like this:
id | place_name | place_street
1 | Place Name One | 1001 Mercury Blvd
2 | Place Name Two | 2388 Jupiter Street
3 | Place Name One | 1001 Mercury Blvd, Suite A
4 | Place Name, One | 1001 Mercury Boulevard
5 | Place Nam Two | 2388 Jupiter Street, Rm 101
What I would like to do is in SQL (this is mssql), if possible, is do a query that is like:
SELECT DISTINCT place_name, place_street where [the first 4 letters of the place_name are the same] && [the first 4 characters of the place_street are the same].
to, I guess at this point, get:
Plac | 1001
Plac | 2388
Basically, then I can figure out what are the main addresses I have to break out into another table to normalize this, because the rest are just slight derivations.
I hope that makes sense.
I've done some research and I see people using regular expressions in SQL, but a lot of them seem to be using C scripts or something. Do I have to write regex functions and save them into the SQL Server before executing any regular expressions?
Any direction on whether I can just write them in SQL or if I have another step to go through would be great.
Or on how to approach this problem.
Thanks in advance!
Use the SQL function LEFT:
SELECT DISTINCT LEFT(place_name, 4)
I don't think you need regular expressions to get the results you describe. You just want to trim the columns and group by the results, which will effectively give you distinct values.
SELECT left(place_name, 4), left(place_street, 4), count(*)
FROM AddressTable
GROUP BY left(place_name, 4), left(place_street, 4)
The count(*) column isn't necessary, but it gives you some idea of which values might have the most (possibly) duplicate address rows in common.
I would recommend you look into Fuzzy Search Operations in SQL Server. You can match the results much better than what you are trying to do. Just google sql server fuzzy search.
Assuming at least SQL Server 2005 for the CTE:
;with cteCommonAddresses as (
select left(place_name, 4) as LeftName, left(place_street,4) as LeftStreet
from Address
group by left(place_name, 4), left(place_street,4)
having count(*) > 1
)
select a.id, a.place_name, a.place_street
from cteCommonAddresses c
inner join Address a
on c.LeftName = left(a.place_name,4)
and c.LeftStreet = left(a.place_street,4)
order by a.place_name, a.place_street, a.id

SQL Query with multiple values in one column

I've been beating my head on the desk trying to figure this one out. I have a table that stores job information, and reasons for a job not being completed. The reasons are numeric,01,02,03,etc. You can have two reasons for a pending job. If you select two reasons, they are stored in the same column, separated by a comma. This is an example from the JOBID table:
Job_Number User_Assigned PendingInfo
1 user1 01,02
There is another table named Pending, that stores what those values actually represent. 01=Not enough info, 02=Not enough time, 03=Waiting Review. Example:
Pending_Num PendingWord
01 Not Enough Info
02 Not Enough Time
What I'm trying to do is query the database to give me all the job numbers, users, pendinginfo, and pending reason. I can break out the first value, but can't figure out how to do the second. What my limited skills have so far:
select Job_number,user_assigned,SUBSTRING(pendinginfo,0,3),pendingword
from jobid,pending
where
SUBSTRING(pendinginfo,0,3)=pending.pending_num and
pendinginfo!='00,00' and
pendinginfo!='NULL'
What I would like to see for this example would be:
Job_Number User_Assigned PendingInfo PendingWord PendingInfo PendingWord
1 User1 01 Not Enough Info 02 Not Enough Time
Thanks in advance
You really shouldn't store multiple items in one column if your SQL is ever going to want to process them individually. The "SQL gymnastics" you have to perform in those cases are both ugly hacks and performance degraders.
The ideal solution is to split the individual items into separate columns and, for 3NF, move those columns to a separate table as rows if you really want to do it properly (but baby steps are probably okay if you're sure there will never be more than two reasons in the short-medium term).
Then your queries will be both simpler and faster.
However, if that's not an option, you can use the afore-mentioned SQL gymnastics to do something like:
where find ( ',' |fld| ',', ',02,' ) > 0
assuming your SQL dialect has a string search function (find in this case, but I think charindex for SQLServer).
This will ensure all sub-columns begin and start with a comma (comma plus field plus comma) and look for a specific desired value (with the commas on either side to ensure it's a full sub-column match).
If you can't control what the application puts in that column, I would opt for the DBA solution - DBA solutions are defined as those a DBA has to do to work around the inadequacies of their users :-).
Create two new columns in that table and make an insert/update trigger which will populate them with the two reasons that a user puts into the original column.
Then query those two new columns for specific values rather than trying to split apart the old column.
This means that the cost of splitting is only on row insert/update, not on _every single select`, amortising that cost efficiently.
Still, my answer is to re-do the schema. That will be the best way in the long term in terms of speed, readable queries and maintainability.
I hope you are just maintaining the code and it's not a brand new implementation.
Please consider to use a different approach using a support table like this:
JOBS TABLE
jobID | userID
--------------
1 | user13
2 | user32
3 | user44
--------------
PENDING TABLE
pendingID | pendingText
---------------------------
01 | Not Enough Info
02 | Not Enough Time
---------------------------
JOB_PENDING TABLE
jobID | pendingID
-----------------
1 | 01
1 | 02
2 | 01
3 | 03
3 | 01
-----------------
You can easily query this tables using JOIN or subqueries.
If you need retro-compatibility on your software you can add a view to reach this goal.
I have a tables like:
Events
---------
eventId int
eventTypeIds nvarchar(50)
...
EventTypes
--------------
eventTypeId
Description
...
Each Event can have multiple eventtypes specified.
All I do is write 2 procedures in my site code, not SQL code
One procedure converts the table field (eventTypeIds) value like "3,4,15,6" into a ViewState array, so I can use it any where in code.
This procedure does the opposite it collects any options your checked and converts it in
If changing the schema is an option (which it probably should be) shouldn't you implement a many-to-many relationship here so that you have a bridging table between the two items? That way, you would store the number and its wording in one table, jobs in another, and "failure reasons for jobs" in the bridging table...
Have a look at a similar question I answered here
;WITH Numbers AS
(
SELECT ROW_NUMBER() OVER(ORDER BY (SELECT 0)) AS N
FROM JobId
),
Split AS
(
SELECT JOB_NUMBER, USER_ASSIGNED, SUBSTRING(PENDING_INFO, Numbers.N, CHARINDEX(',', PENDING_INFO + ',', Numbers.N) - Numbers.N) AS PENDING_NUM
FROM JobId
JOIN Numbers ON Numbers.N <= DATALENGTH(PENDING_INFO) + 1
AND SUBSTRING(',' + PENDING_INFO, Numbers.N, 1) = ','
)
SELECT *
FROM Split JOIN Pending ON Split.PENDING_NUM = Pending.PENDING_NUM
The basic idea is that you have to multiply each row as many times as there are PENDING_NUMs. Then, extract the appropriate part of the string
While I agree with DBA perspective not to store multiple values in a single field it is doable, as bellow, practical for application logic and some performance issues. Let say you have 10000 user groups, each having average 1000 members. You may want to have a table user_groups with columns such as groupID and membersID. Your membersID column could be populated like this:
(',10,2001,20003,333,4520,') each number being a memberID, all separated with a comma. Add also a comma at the start and end of the data. Then your select would use like '%,someID,%'.
If you can not change your data ('01,02,03') or similar, let say you want rows containing 01 you still can use " select ... LIKE '01,%' OR '%,01' OR '%,01,%' " which will insure it match if at start, end or inside, while avoiding similar number (ie:101).