Merge data into one column - sql server 2012 - sql

How can I merge data into one column for different account numbers. Currently, it looks like this.
TableA.Order TableA.Question TableB.Response
1 a Null
1 b James
1 c Null
2 d Zebra
2 T Null
However, I want it to merge like below:
TableA.Order NewColumn
1 a
1 b
1 c
1 James
2 d
2 T
2 Zebra

Base from my understanding of your question. I devised a solution which answers to it. See my query below:
SELECT * FROM TableA
UNION ALL
SELECT B.Order1,A.Response From
(
(SELECT ROW_NUMBER()OVER(ORDER BY Response)PK,* FROM TableB) A Left Join
(SELECT ROW_NUMBER()OVER(ORDER BY Order1)PK,* FROM TableA) B On A.PK=B.PK
)
Where Response IS NOT NULL

Related

How to get distinct count over multiple columns in SQL?

I have a table that looks like this. And I want to get the distinct count across the three columns.
ID
Column1
Column 2
Column 3
1
A
B
C
2
A
A
B
3
A
A
The desired output I'm looking for is:
ID
Column1
Column 2
Column 3
unique_count
1
A
B
C
3
2
A
A
B
2
3
A
A
1
You want to use cross apply for this one.
select *
from t cross apply
(select count(distinct cnt) as unique_count
from (values(Column1),(Column2),(Column3)) t(cnt)) t2
ID
Column1
Column2
Column3
unique_count
1
A
B
C
3
2
A
A
B
2
3
A
A
1
Fiddle
In standard SQL, you have to UNPIVOT first, do the count(distinct) group by on the PIVOTed result and then PIVOT again.
In recent ORACLE version, you could write your own Polymorphic Table Function to do it, passing the table and the list of columns to count for DISTINCT values.
try if this works
SELECT Count(*)
FROM (SELECT DISTINCT Column1 FROM TABLENAME);

SQL query - Cumulatively concatenate strings in consecutive rows

I'm a data analyst, so I write SQL queries to retrieve data from a database. I'm not sure what kind of SQL exactly, just assume the most standard (also not things like 'DECLARE #tbl', and no create functions etc.)
Here is my problem.
Given the following table:
name
number
letter
A
1
a
A
2
b
A
3
c
A
4
d
B
1
a
B
2
b
B
3
c
B
4
d
I want the following result: (concatenate letter cumulatively, order by number))
name
number
letter
result
A
1
a
a
A
2
b
a,b
A
3
c
a,b,c
A
4
d
a,b,c,d
B
1
a
a
B
2
b
a,b
B
3
c
a,b,c
B
4
d
a,b,c,d
Any help is highly appreciated. Thanks very much.
This answers the original version of the question which was tagged MySQL.
MySQL doesn't support group_concat() as a window function. So a subquery may be your best alternative:
select t.*,
(select group_concat(t2.letter order by t2.number)
from t t2
where t2.name = t.name and t2.number <= t.number
) as letters
from t;

Which kind of join do I need to use here?

For every row in table Y, I need a copy of the current row in Table X, taking field 1 from Table Y.
Table X
Field 1 Field 2
null A
null B
null C
Table Y
Field 1
1
2
3
Desired output
Field 1 Field 2
1 A
1 B
1 C
2 A
2 B
2 C
3 A
3 B
3 C
Looks like a cross join:
select y.field1, x.field2
from x cross join
y;
Looks like an unconditional select of both tables without matching ids
Something like
select tableY.column1, tableX.column2
from tableY, tableX
order by tableY.column1 asc, tableX.column2 asc
should do it.
BTW. Was this a school question, because then I should not have answered this.
Try this query:
SELECT #Tabley.Field1 , #TableX.Field2
FROM #TableX ,#Tabley

Query to find records following same sequence of patterns?

How to find records which matches certain sequences from the below table:
ID s_id task
1 1 a
1 2 b
1 3 b
1 4 c
1 5 c
1 6 d
1 7 a
2 1 a
2 2 c
2 3 c
3 1 a
3 2 b
3 3 c
3 4 d
1 1 a
1 2 b
1 3 c
1 4 c
1 5 e
1 6 d
How to fetch the records following the below pattern
a
1 or more b
c
Below code will transform your data to a list of site visits (id) followed by a single string of characters representing pages visited (e.g. "abbbcd").
SELECT t2.id, max(tasks) as tasks from
(
SELECT t1.id,
(SELECT '' + Task FROM [Table] WHERE id = t1.id ORDER BY s_Id FOR XML PATH('')) AS tasks
from [Table] t1
) t2
group by t2.id
So the problem is now reduced to searching for a pattern of characters: a--any number of b's--c. You can use LIKE to do this:
SELECT *
FROM (
SELECT t2.id, max(tasks) as tasks from
(
SELECT t1.id,
(SELECT '' + Task FROM [Table] WHERE id = t1.id ORDER BY s_Id FOR XML PATH('')) AS tasks
from [Table] t1
) t2
group by t2.id
) t3
WHERE t3.tasks LIKE '%abc%'
OR t3.tasks LIKE '%abbc%'
OR t3.tasks LIKE '%abbbc%'
OR t3.tasks LIKE '%abbbbc%';
This is a bit crude. You want to say any number of b's, but LIKE does not support that. This is what regular expressions (RegEx) is normally used for. The expression would be "ab+c" which stand for: "a" followed by 1 or more "b"s, followed by a "c".
Unfortunately, SQL server does not support regex (Oracle does), so you have to use CLR to implement it. Others have done this for you, so you can follow instructions here to install it: https://www.simple-talk.com/sql/t-sql-programming/clr-assembly-regex-functions-for-sql-server-by-example/

Merging columns in a join of two tables

I have the following tables in a Hive database:
table1:
id t X
1 1 a
1 4 a
2 5 a
3 10 a
table2:
id t Y
1 3 b
2 6 b
2 8 b
3 15 b
And I would like to merge them to have a table like:
id t Z
1 1 a
1 3 b
1 4 a
2 5 a
2 6 b
2 8 b
3 10 a
3 15 b
Basically what I want to do is :
a join on the column id (that part is easy)
merge the columns table1.t and table2.t into a new column t
have the variable Z that is equal to table1.X if the corresponding t comes from table1.t, and table2.Y if it comes from table2.t
order the table by id and then by t (that shouldn't be too hard)
I have no idea on how to do the parts 2 and 3. I tried with an outer join on
table1.id = table2.id and table1.t = table2.t, but it doesn't merge the two columns t.
Any pointer would be appreciated. Thanks!
CREATE TABLE table3 as SELECT * FROM (SELECT id,t,X as Z FROM t3_1 UNION ALL SELECT id,t,Y as Z FROM t3_2) u1 order by id,t;
Although not always required, using a subquery for the union'd queries help to organize, plus you can then reference the fields from the union (e.g. u1.id ) in other parts of the query.
You'll need the alias on the 3rd column to make the schemas match. If the source table name was not already a column, you could do something like this:
select * from (select id,t,'a' from t3_1 UNION ALL select id,t,'b' from t3_2) u1;
Try this one. It will insert in table 3, all the values from the other 2 tables
INSERT INTO table3 ( t, Z )
SELECT t, X
FROM table1
UNION ALL
SELECT t, Y
FROM table2