I have 12 tables in SQL Server with the exact same columns that I would like to combine into one brand new table. I don't want any data/rows deleted.
Thanks
Use union all:
insert into NewTable(col1, col2)
select col1, col2
from(
select col1, col2 from Table1
union all
select col1, col2 from Table2
union all
select col1, col2 from Table3
.....
)t
You can create new table while selecting like:
select col1, col2
into NewTable
from(
select col1, col2 from Table1
union all
select col1, col2 from Table2
union all
select col1, col2 from Table3
.....
)t
Related
I have a table similar to this
Can I get help writing up a query which will join col1, col2 & col3 and give me a result as below
I've spent an hour trying to figure it out with my mediocre skills and have got to some point.
select col1, count(*)
from tableName
group by col1
But I can't figure out how to join all three cols.
try this one
select
col,
count(*)
from
(select
id,
col1 as col
from
<table_name>
union all
select
id,
col2
from
<table_name>
union all
select
id,
col3
from
<table_name>)
group by
col
You need to group by col of the union of the 3 columns:
select t.col, count(*)
from (
select col1 col from tablename
union all
select col2 from tablename
union all
select col3 from tablename
) t
group by t.col
You should use UNION to group values from all columns to one column. After that, you can count values
SELECT
col,
count(*) as cnt
FROM
(SELECT col1 as col FROM table1
UNION ALL
SELECT col2 as col FROM table1
UNION ALL
SELECT col2 as col FROM table1) as t
GROUP BY col
I am currently using UNION on two queries (see psuedo-code below):
query1
UNION
query2
I want to add an additional column to my results that says the source of the data. The new column called "Source" would return one of the following: "1", "2", or "both".
Being able to handle "both" is very important because query1 and query2 will have similar results and many overlapping records. If anyone could help point me in the right direction, especially with how to handle the "both" case, that would be greatly appreciated!
Sample:
If query1 has a row "Apple,Yellow,Bob" and query2 has the same row, then the result I'm hoping for is:
"Apple,Yellow,Bob,Both"
The individual queries themselves will not have duplicates, but there may be the same row both in query1 and query2 (as seen above).
you can make use of an additional column col4 like this
select col1,col2,col3,sum(col4)
from(
Select col1, col2, col3, 1 as col4 from table1
UNION
Select col1,col2,col3, 2 as col4 from table4
)
group by col1,col2,col3
The records with col4=1 only exist in table1.
The records with col4=2 only exist in table2.
The records with col4=3 exist in both table1+table
add a Source field to both query 1 and query 2:
select 1 as source, ...
from table1
union
select 2 as source, ...
from table2
Here's one way
WITH T
AS (SELECT '1' AS Source,
Col1,
Col2,
Col3
FROM table1
UNION ALL
SELECT '2' AS Source,
Col1,
Col2,
Col3
FROM table2)
SELECT CASE
WHEN MAX(Source) = MIN(Source) THEN Source
ELSE 'Both'
END AS Source,
Col1,
Col2,
Col3
FROM T
GROUP BY Col1,
Col2,
Col3
One more approach
SELECT col1
,col2
,source = CASE
WHEN count(DISTINCT source) > 1
THEN 'Both'
ELSE max(source)
END
FROM (
SELECT col1 ,col2, source = 'source1'
FROM source1
UNION ALL
SELECT col1, col2, source = 'source2'
FROM source2
) u
GROUP BY col1, col2
You can try this
SELECT
a.col1 , a.col2,
CASE WHEN MAX(a.Source) <> MIN(a.Source)
THEN 'BOTH'
ELSE MAX(a.Source) END
FROM
(
SELECT
col1, col2 ,'Source2' AS Source
FROM Table1
UNION ALL
SELECT
col1, col2 ,'Source1' AS Source
FROM Table2
) a
GROUP BY
a.col1 , a.col2
Link to the Sample
I have the following sql at the begnging.
select col1, col2 from table1
union
select col1, col2 from table2
Now I want to able to do a count the total number of rows in the union set from above, and order by col2. How should I do this?
with a as (
select col1, col2 from table1
union
select col1, col2 from table2
)
select *,count(1) over()
from a
order by col2
;
I am trying to combine three tables in an SQLite database into one new combined table. The three tables have the same column names, but the third table is missing one of the columns. Here is how I am trying to do it:
CREATE TABLE cobmined
AS
SELECT col1, col2, col3
FROM
(
SELECT col1, col2, col3 from table1
UNION ALL
SELECT col1, col2, col3 from table2
UNION ALL
SELECT col1, col2 from table3
) s
;
This works when doing this only on the first two tables, when adding the third table I get the message:
SELECTs to the left and right of UNION do not have the same number of result columns
Is there a way to let SQL ignore the missing column and leave it with NULLs if needed?
Add a NULL value to the third table
CREATE TABLE cobmined
AS
SELECT col1, col2, col3
FROM
(
SELECT col1, col2, col3 from table1
UNION ALL
SELECT col1, col2, col3 from table2
UNION ALL
SELECT col1, col2, null from table3
) s
;
Also, no need for sub-query
CREATE TABLE cobmined
AS
SELECT col1, col2, col3 from table1
UNION ALL
SELECT col1, col2, col3 from table2
UNION ALL
SELECT col1, col2, null from table3
I want to note that you don't need the subquery:
CREATE TABLE combined AS
SELECT col1, col2, col3 from table1
UNION ALL
SELECT col1, col2, col3 from table2
UNION ALL
SELECT col1, col2, NULL from table3;
In addition, you may find that a view is more suitable for your purposes than an actual table.
SELECT DISTINCT col1, col2 FROM table t ORDER BY col1;
This gives me distinct combination of col1 & col2. Is there an alternative way of writing the Oracle SQL query to get the unique combination of col1 & col2 records with out using the keyword distinct?
Use the UNIQUE keyword which is a synonym for DISTINCT:
SELECT UNIQUE col1, col2 FROM table t ORDER BY col1;
I don't see why you would want to but you could do
SELECT col1, col2 FROM table_t GROUP BY col1, col2 ORDER BY col1
Another - yet overly complex and somewhat useless - solution:
select *
from (
select col1,
col2,
row_number() over (partition by col1, col2 order by col1, col2) as rn
from the_table
)
where rn = 1
order by col1
select col1, col2
from table
group by col1, col2
order by col1
or a less elegant way:
select col1,col2 from table
UNION
select col1,col2 from table
order by col1;
or a even less elegant way:
select a.col1, a.col2
from (select col1, col2 from table
UNION
select NULL, NULL) a
where a.col1 is not null
order by a.col1
Yet another ...
select
col1,
col2
from
table t1
where
not exists (select *
from table t2
where t2.col1 = t1.col1 and
t2.col2 = t1.col2 and
t2.rowid > t1.rowid)
order by
col1;
Variations on the UNION solution by #aF. :
INTERSECT
SELECT col1, col2 FROM tableX
INTERSECT
SELECT col1, col2 FROM tableX
ORDER BY col1;
MINUS
SELECT col1, col2 FROM tableX
MINUS
SELECT col1, col2 FROM tableX WHERE 0 = 1
ORDER BY col1;
MINUS (2nd version, it will return one row less than the other versions, if there is (NULL, NULL) group)
SELECT col1, col2 FROM tableX
MINUS
SELECT NULL, NULL FROM dual
ORDER BY col1;
Another ...
select col1,
col2
from (
select col1,
col2,
rowid,
min(rowid) over (partition by col1, col2) min_rowid
from table)
where rowid = min_rowid
order by col1;