SQL Server: Examples of PIVOTing String data - sql-server

Trying to find some simple SQL Server PIVOT examples. Most of the examples that I have found involve counting or summing up numbers. I just want to pivot some string data. For example, I have a query returning the following.
Action1 VIEW
Action1 EDIT
Action2 VIEW
Action3 VIEW
Action3 EDIT
I would like to use PIVOT (if even possible) to make the results like so:
Action1 VIEW EDIT
Action2 VIEW NULL
Action3 VIEW EDIT
Is this even possible with the PIVOT functionality?

Remember that the MAX aggregate function will work on text as well as numbers. This query will only require the table to be scanned once.
SELECT Action,
MAX( CASE data WHEN 'View' THEN data ELSE '' END ) ViewCol,
MAX( CASE data WHEN 'Edit' THEN data ELSE '' END ) EditCol
FROM t
GROUP BY Action

Table setup:
CREATE TABLE dbo.tbl (
action VARCHAR(20) NOT NULL,
view_edit VARCHAR(20) NOT NULL
);
INSERT INTO dbo.tbl (action, view_edit)
VALUES ('Action1', 'VIEW'),
('Action1', 'EDIT'),
('Action2', 'VIEW'),
('Action3', 'VIEW'),
('Action3', 'EDIT');
Your table:
SELECT action, view_edit FROM dbo.tbl
Query without using PIVOT:
SELECT Action,
[View] = (Select view_edit FROM tbl WHERE t.action = action and view_edit = 'VIEW'),
[Edit] = (Select view_edit FROM tbl WHERE t.action = action and view_edit = 'EDIT')
FROM tbl t
GROUP BY Action
Query using PIVOT:
SELECT [Action], [View], [Edit] FROM
(SELECT [Action], view_edit FROM tbl) AS t1
PIVOT (MAX(view_edit) FOR view_edit IN ([View], [Edit]) ) AS t2
Both queries result:

If you specifically want to use the SQL Server PIVOT function, then this should work, assuming your two original columns are called act and cmd. (Not that pretty to look at though.)
SELECT act AS 'Action', [View] as 'View', [Edit] as 'Edit'
FROM (
SELECT act, cmd FROM data
) AS src
PIVOT (
MAX(cmd) FOR cmd IN ([View], [Edit])
) AS pvt

From http://blog.sqlauthority.com/2008/06/07/sql-server-pivot-and-unpivot-table-examples/:
SELECT CUST, PRODUCT, QTY
FROM Product) up
PIVOT
( SUM(QTY) FOR PRODUCT IN (VEG, SODA, MILK, BEER, CHIPS)) AS pvt) p
UNPIVOT
(QTY FOR PRODUCT IN (VEG, SODA, MILK, BEER, CHIPS)
) AS Unpvt
GO

Well, for your sample and any with a limited number of unique columns, this should do it.
select
distinct a,
(select distinct t2.b from t t2 where t1.a=t2.a and t2.b='VIEW'),
(select distinct t2.b from t t2 where t1.a=t2.a and t2.b='EDIT')
from t t1

With pivot_data as
(
select
action, -- grouping column
view_edit -- spreading column
from tbl
)
select action, [view], [edit]
from pivot_data
pivot ( max(view_edit) for view_edit in ([view], [edit]) ) as p;

I had a situation where I was parsing strings and the first two positions of the string in question would be the field names of a healthcare claims coding standard. So I would strip out the strings and get values for F4, UR and UQ or whatnot. This was great on one record or a few records for one user. But when I wanted to see hundreds of records and the values for all usersz it needed to be a PIVOT. This was wonderful especially for exporting lots of records to excel. The specific reporting request I had received was "every time someone submitted a claim for Benadryl, what value did they submit in fields F4, UR, and UQ. I had an OUTER APPLY that created the ColTitle and the value fields below
PIVOT(
min(value)
FOR ColTitle in([F4], [UR], [UQ])
)

Related

How to use cross apply string split result to update a table in sql?

I am trying to split a column('categories') of a Table 'movies_titles' which has string separated data values in it.
e.g:
ID title categories
1 Movie A Comedy, Drama, Romance
2 Movie B Animation
3 Movie C Documentary, Life changing
I want to split the comma delimited string and place each values in a separate rows and update the table
-- this query shows the splitted strings as I want it
SELECT *
FROM dbo.movies_titles
CROSS APPLY
string_split(categories, ',')
O/P:
ID title categories value
1 Movie A Comedy, Drama, Romance Comedy
1 Movie A Comedy, Drama, Romance Drama
1 Movie A Comedy, Drama, Romance Romance
2 Movie B Animation Animation
3 Movie C Documentary, Life changing Documentary
3 Movie C Documentary, Life changing Life changing
I want to use UPDATE query to set the result obtained from value column. I just don't want to use SELECT query to view the result but permanently update the changes to the table. How do I achieve this in sql server?
You can do something similar to your intention creating new rows, because the update statement won't create the additional rows made by the split.
There can be issues if the ID column is unique, like a primary key, and there is the need to keep the title associated with that column.
I've created two scenarios on DB Fiddle, showing how you can do this using only one table as the question instructed, but a better alternative would be to save this information on another table.
This code on DB Fiddle: link
--Assuming your table is something like this
create table movies_id_as_pk (
ID int identity(1,1) primary key,
title varchar(200),
categories varchar(200),
category varchar(200)
)
--Or this
create table movies_other_pk (
another_id int identity(1,1) primary key,
ID int,
title varchar(200),
categories varchar(200),
category varchar(200)
)
--The example data
set identity_insert movies_id_as_pk on
insert into movies_id_as_pk (ID, title, categories) values
(1, 'Movie A', 'Comedy, Drama, Romance'),
(2, 'Movie B', 'Animation'),
(3, 'Movie C', 'Documentary, Life changing')
set identity_insert movies_id_as_pk off
insert into movies_other_pk (ID, title, categories)
select ID, title, categories from movies_id_as_pk
--You can't update directly any of the tables, because as the result of the split
--have more rows than the table, it would just leave the first value found:
update m set category = rtrim(ltrim(s.value))
from movies_id_as_pk m
cross apply string_split(m.categories, ',') as s
update m set category = rtrim(ltrim(s.value))
from movies_other_pk m
cross apply string_split(m.categories, ',') as s
select * from movies_id_as_pk
select * from movies_other_pk
--What you can do is create the aditional rows, inserting them:
--First, let's undo what the last instructions have changed
update movies_id_as_pk set category=NULL
update movies_other_pk set category=NULL
--Then use inserts to create the rows with the categories split
insert into movies_id_as_pk (title, category)
select m.title, rtrim(ltrim(s.value))
from movies_id_as_pk m
cross apply string_split(m.categories, ',') as s
insert into movies_other_pk (ID, title, category)
select m.ID, m.title, rtrim(ltrim(s.value))
from movies_other_pk m
cross apply string_split(m.categories, ',') as s
select * from movies_id_as_pk
select * from movies_other_pk
It actually is possible to insert or update at the same time. That is to say: we can update each row with a single category, then create new rows for the extra ones.
We can use MERGE for this. We can use the same table as source and target. We just need to split the source, then add a row-number partitioned per each original row. We then filter the ON clause to match only the first row.
WITH Source AS (
SELECT
m.ID,
m.title,
category = TRIM(cat.value),
rn = ROW_NUMBER() OVER (PARTITION BY ID ORDER BY (SELECT NULL))
FROM movies m
CROSS APPLY STRING_SPLIT(m.categories, ',') cat
)
MERGE movies t
USING Source s
ON s.ID = t.ID AND s.rn = 1
WHEN MATCHED THEN
UPDATE
SET categories = s.category
WHEN NOT MATCHED THEN
INSERT (ID, title, categories)
VALUES (s.ID, s.title, s.category)
;
db<>fiddle
I wouldn't necessarily recommend this as a general solution though, because it appears you actually have other normalization problems to sort out first. You should really have separate tables for all this information:
Movie
Category
MovieCategory

How to write the COLUMNS to ROWS in SQL server [duplicate]

Looking for elegant (or any) solution to convert columns to rows.
Here is an example: I have a table with the following schema:
[ID] [EntityID] [Indicator1] [Indicator2] [Indicator3] ... [Indicator150]
Here is what I want to get as the result:
[ID] [EntityId] [IndicatorName] [IndicatorValue]
And the result values will be:
1 1 'Indicator1' 'Value of Indicator 1 for entity 1'
2 1 'Indicator2' 'Value of Indicator 2 for entity 1'
3 1 'Indicator3' 'Value of Indicator 3 for entity 1'
4 2 'Indicator1' 'Value of Indicator 1 for entity 2'
And so on..
Does this make sense? Do you have any suggestions on where to look and how to get it done in T-SQL?
You can use the UNPIVOT function to convert the columns into rows:
select id, entityId,
indicatorname,
indicatorvalue
from yourtable
unpivot
(
indicatorvalue
for indicatorname in (Indicator1, Indicator2, Indicator3)
) unpiv;
Note, the datatypes of the columns you are unpivoting must be the same so you might have to convert the datatypes prior to applying the unpivot.
You could also use CROSS APPLY with UNION ALL to convert the columns:
select id, entityid,
indicatorname,
indicatorvalue
from yourtable
cross apply
(
select 'Indicator1', Indicator1 union all
select 'Indicator2', Indicator2 union all
select 'Indicator3', Indicator3 union all
select 'Indicator4', Indicator4
) c (indicatorname, indicatorvalue);
Depending on your version of SQL Server you could even use CROSS APPLY with the VALUES clause:
select id, entityid,
indicatorname,
indicatorvalue
from yourtable
cross apply
(
values
('Indicator1', Indicator1),
('Indicator2', Indicator2),
('Indicator3', Indicator3),
('Indicator4', Indicator4)
) c (indicatorname, indicatorvalue);
Finally, if you have 150 columns to unpivot and you don't want to hard-code the entire query, then you could generate the sql statement using dynamic SQL:
DECLARE #colsUnpivot AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX)
select #colsUnpivot
= stuff((select ','+quotename(C.column_name)
from information_schema.columns as C
where C.table_name = 'yourtable' and
C.column_name like 'Indicator%'
for xml path('')), 1, 1, '')
set #query
= 'select id, entityId,
indicatorname,
indicatorvalue
from yourtable
unpivot
(
indicatorvalue
for indicatorname in ('+ #colsunpivot +')
) u'
exec sp_executesql #query;
well If you have 150 columns then I think that UNPIVOT is not an option. So you could use xml trick
;with CTE1 as (
select ID, EntityID, (select t.* for xml raw('row'), type) as Data
from temp1 as t
), CTE2 as (
select
C.id, C.EntityID,
F.C.value('local-name(.)', 'nvarchar(128)') as IndicatorName,
F.C.value('.', 'nvarchar(max)') as IndicatorValue
from CTE1 as c
outer apply c.Data.nodes('row/#*') as F(C)
)
select * from CTE2 where IndicatorName like 'Indicator%'
sql fiddle demo
You could also write dynamic SQL, but I like xml more - for dynamic SQL you have to have permissions to select data directly from table and that's not always an option.
UPDATEAs there a big flame in comments, I think I'll add some pros and cons of xml/dynamic SQL. I'll try to be as objective as I could and not mention elegantness and uglyness. If you got any other pros and cons, edit the answer or write in comments
cons
it's not as fast as dynamic SQL, rough tests gave me that xml is about 2.5 times slower that dynamic (it was one query on ~250000 rows table, so this estimate is no way exact). You could compare it yourself if you want, here's sqlfiddle example, on 100000 rows it was 29s (xml) vs 14s (dynamic);
may be it could be harder to understand for people not familiar with xpath;
pros
it's the same scope as your other queries, and that could be very handy. A few examples come to mind
you could query inserted and deleted tables inside your trigger (not possible with dynamic at all);
user don't have to have permissions on direct select from table. What I mean is if you have stored procedures layer and user have permissions to run sp, but don't have permissions to query tables directly, you still could use this query inside stored procedure;
you could query table variable you have populated in your scope (to pass it inside the dynamic SQL you have to either make it temporary table instead or create type and pass it as a parameter into dynamic SQL;
you can do this query inside the function (scalar or table-valued). It's not possible to use dynamic SQL inside the functions;
Just to help new readers, I've created an example to better understand #bluefeet's answer about UNPIVOT.
SELECT id
,entityId
,indicatorname
,indicatorvalue
FROM (VALUES
(1, 1, 'Value of Indicator 1 for entity 1', 'Value of Indicator 2 for entity 1', 'Value of Indicator 3 for entity 1'),
(2, 1, 'Value of Indicator 1 for entity 2', 'Value of Indicator 2 for entity 2', 'Value of Indicator 3 for entity 2'),
(3, 1, 'Value of Indicator 1 for entity 3', 'Value of Indicator 2 for entity 3', 'Value of Indicator 3 for entity 3'),
(4, 2, 'Value of Indicator 1 for entity 4', 'Value of Indicator 2 for entity 4', 'Value of Indicator 3 for entity 4')
) AS Category(ID, EntityId, Indicator1, Indicator2, Indicator3)
UNPIVOT
(
indicatorvalue
FOR indicatorname IN (Indicator1, Indicator2, Indicator3)
) UNPIV;
Just because I did not see it mentioned.
If 2016+, here is yet another option to dynamically unpivot data without actually using Dynamic SQL.
Example
Declare #YourTable Table ([ID] varchar(50),[Col1] varchar(50),[Col2] varchar(50))
Insert Into #YourTable Values
(1,'A','B')
,(2,'R','C')
,(3,'X','D')
Select A.[ID]
,Item = B.[Key]
,Value = B.[Value]
From #YourTable A
Cross Apply ( Select *
From OpenJson((Select A.* For JSON Path,Without_Array_Wrapper ))
Where [Key] not in ('ID','Other','Columns','ToExclude')
) B
Returns
ID Item Value
1 Col1 A
1 Col2 B
2 Col1 R
2 Col2 C
3 Col1 X
3 Col2 D
I needed a solution to convert columns to rows in Microsoft SQL Server, without knowing the colum names (used in trigger) and without dynamic sql (dynamic sql is too slow for use in a trigger).
I finally found this solution, which works fine:
SELECT
insRowTbl.PK,
insRowTbl.Username,
attr.insRow.value('local-name(.)', 'nvarchar(128)') as FieldName,
attr.insRow.value('.', 'nvarchar(max)') as FieldValue
FROM ( Select
i.ID as PK,
i.LastModifiedBy as Username,
convert(xml, (select i.* for xml raw)) as insRowCol
FROM inserted as i
) as insRowTbl
CROSS APPLY insRowTbl.insRowCol.nodes('/row/#*') as attr(insRow)
As you can see, I convert the row into XML (Subquery select i,* for xml raw, this converts all columns into one xml column)
Then I CROSS APPLY a function to each XML attribute of this column, so that I get one row per attribute.
Overall, this converts columns into rows, without knowing the column names and without using dynamic sql. It is fast enough for my purpose.
(Edit: I just saw Roman Pekar answer above, who is doing the same.
I used the dynamic sql trigger with cursors first, which was 10 to 100 times slower than this solution, but maybe it was caused by the cursor, not by the dynamic sql. Anyway, this solution is very simple an universal, so its definitively an option).
I am leaving this comment at this place, because I want to reference this explanation in my post about the full audit trigger, that you can find here: https://stackoverflow.com/a/43800286/4160788
DECLARE #TableName varchar(max)=NULL
SELECT #TableName=COALESCE(#TableName+',','')+t.TABLE_CATALOG+'.'+ t.TABLE_SCHEMA+'.'+o.Name
FROM sysindexes AS i
INNER JOIN sysobjects AS o ON i.id = o.id
INNER JOIN INFORMATION_SCHEMA.TABLES T ON T.TABLE_NAME=o.name
WHERE i.indid < 2
AND OBJECTPROPERTY(o.id,'IsMSShipped') = 0
AND i.rowcnt >350
AND o.xtype !='TF'
ORDER BY o.name ASC
print #tablename
You can get list of tables which has rowcounts >350 . You can see at the solution list of table as row.
The opposite of this is to flatten a column into a csv eg
SELECT STRING_AGG ([value],',') FROM STRING_SPLIT('Akio,Hiraku,Kazuo', ',')

SELECT INTO query

I have to write an SELECT INTO T-SQL script for a table which has columns acc_number, history_number and note.
How do i facilitate an incremental value of history_number for each record being inserted via SELECT INTO.
Note, that the value for history_number comes off as a different value for each account from a different table.
SELECT history_number = IDENTITY(INT,1,1),
... etc...
INTO NewTable
FROM ExistingTable
WHERE ...
You could use ROW_NUMBER instead of identity i.e. ROW_NUMBER() OVER (ORDER BY )
SELECT acc_number
,o.historynumber
,note
,o.historynumber+DENSE_RANK() OVER (Partition By acc_number ORDER BY Note) AS NewHistoryNumber
--Or some other order by probably a timestamp...
FROM Table t
INNER JOIN OtherTable o
ON ....
Working Fiddle
The will give you an incremented count starting from history number for each accnum. I suggest you use a better order by in the rank but there was not enough info in the question.
This answer to this question may help you as well
Question
Suppose your SELECT statement is like this
SELECT acc_number,
history_number,
note
FROM [Table]
Try this Query as below.
SELECT ROW_NUMBER() OVER (ORDER BY acc_number) ID,
acc_number,
history_number,
note
INTO [NewTable]
FROM [Table]

SQL Server query to generate dynamic columns

I have two tables - one is state and other one is for Job titles.
I want to write a query which will output me something like this:-
Job titles State name1 State name2
Job title1 200 300
Job title2 500 600
How can I write this query in SQL Server.
I have no idea what your schema looks like, but it sounds like you want to change it to have three tables: JobTitle, State, and JobTitle_State_Salary. That way you're not repeating either job titles or states in order to tie to salary.
However, addressing the problem as written (and making the assumption that salary travels with state), something like this should do the trick:
WITH [CTE] AS
(
SELECT [Title], [State], [Salary]
FROM [JobTitle]
INNER JOIN [StateSalary]
ON [JobTitle].[ID] = [StateSalary].[JobTitleID]
)
SELECT
[Title], [State name1], [State name2]
FROM
[CTE]
PIVOT
(
MAX([Salary])
FOR [State] IN ([State name1], [State name2])
) AS [P]
SQLFiddle example here.
As zimdanen said, it would be difficult to write the query without knowing the exact table structure.
I assumed for structure that JobTitle table has JobTitleId and JobTitle fields, and that *state_salary* table has JobTitleId, State, and Salary as fields.
USING PIVOT TABLE
SELECT * FROM (
SELECT A.JOB_TITLE,B.STATE,B.SALARY FROM dbo.JOB_TITLE A INNER JOIN dbo.STATE_SALARY B
ON A.JOB_TITLE_ID = B.JOB_TITLE_ID)AS SOURCE_TABLE PIVOT
(SUM(SALARY) FOR STATE IN (STATE1,STATE2)) AS PivotTable
Without Pivot Table
SELECT A.JOB_TITLE,SUM(CASE WHEN B.STATE = 'State1' THEN B.SALARY ELSE 0 END) STATE1, SUM(CASE WHEN B.STATE = 'State2' THEN B.SALARY ELSE 0 END) STATE2
FROM dbo.JOB_TITLE A INNER JOIN dbo.STATE_SALARY B
ON A.JOB_TITLE_ID = B.JOB_TITLE_ID
GROUP BY A.JOB_TITLE
If you are using sqlserver 2005 or greater you can try using pivot table

Keeping it simple and how to do multiple CTE in a query

I have this simple T-SQL query, it emits a bunch of columns from a table and also joins information from other related tables.
My data model is simple. I have a scheduled event, with participants. I need to know how many participants participate in each event.
My solution to this is to add a CTE that groups scheduled events and counts the number of participants.
This will allow me to join in that information per scheduled event. Keeping the query simple.
I like to keep my queries simple, however, If I ever in the future need to have additonal temporary results accessible during my simple query, what do I do?
I would really like it, if I could have multiple CTEs but I can't, right? What are my options here?
I've ruled out views and doing things at the application data layer. I prefer to isolated my SQL queries.
You can have multiple CTEs in one query, as well as reuse a CTE:
WITH cte1 AS
(
SELECT 1 AS id
),
cte2 AS
(
SELECT 2 AS id
)
SELECT *
FROM cte1
UNION ALL
SELECT *
FROM cte2
UNION ALL
SELECT *
FROM cte1
Note, however, that SQL Server may reevaluate the CTE each time it is accessed, so if you are using values like RAND(), NEWID() etc., they may change between the CTE calls.
You certainly are able to have multiple CTEs in a single query expression. You just need to separate them with a comma. Here is an example. In the example below, there are two CTEs. One is named CategoryAndNumberOfProducts and the second is named ProductsOverTenDollars.
WITH CategoryAndNumberOfProducts (CategoryID, CategoryName, NumberOfProducts) AS
(
SELECT
CategoryID,
CategoryName,
(SELECT COUNT(1) FROM Products p
WHERE p.CategoryID = c.CategoryID) as NumberOfProducts
FROM Categories c
),
ProductsOverTenDollars (ProductID, CategoryID, ProductName, UnitPrice) AS
(
SELECT
ProductID,
CategoryID,
ProductName,
UnitPrice
FROM Products p
WHERE UnitPrice > 10.0
)
SELECT c.CategoryName, c.NumberOfProducts,
p.ProductName, p.UnitPrice
FROM ProductsOverTenDollars p
INNER JOIN CategoryAndNumberOfProducts c ON
p.CategoryID = c.CategoryID
ORDER BY ProductName

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