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
Related
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);
Lets say I have a table of the following form,
X | Y | Z
_________
1 A 3
1 B 3
1 C 4
1 B 4
and I want to query the record which contains B, but only those records that contain B and do not share a common Z field value with a specific record, in this case say A. Thus, ideally the query would return the record "1 B 4".
You could use not exists:
select t.*
from t
where t.y = 'B' and
not exists (select 1 from t t2 where t2.z = t.z and t2.y = 'A');
With indexes on (z, y) and (y) this is likely to be the fastest method as well.
I have a problem which I can't describe without explaining this on this example:
So there are 2 columns like:
X Y
A 2
A 1
A 3
B 3
C 2
A 1
D 2
B 1
B 3
C 1
A 1
D 3
D 1
and now I would like to select only that data from X, where one of the values from Y is 2.
So my output should look like:
X Y
A 2
A 1
A 3
C 2
A 1
D 2
C 1
A 1
D 3
D 1
because Y=2 for X=B doesn't exist in the main table.
My question is what is the query for this operation? I tried something with CASE WHEN but something didn't fix for me.
Try
SELECT X FROM Table WHERE X IN (SELECT X FROM Table WHERE Y=2)
OR Try
SELECT t1.X FROM Table t1
INNER JOIN Table t2 ON t1.X = t2.X
WHERE t2.Y = 2
Try a subquery:
SELECT X FROM table WHERE X IN (SELECT X FROM table WHERE Y = 2);
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
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