I am looking for a way to count for the same column in two different tables.
So I have two tables, table1 and table2. They both have the column "category". I want to find a way to count category for these two tables and show as the result below.
I know how to do this individually by
select category, count(category) as cnt from table1
group by category
order by cnt desc
select category, count(category) as cnt from table2
group by category
order by cnt desc
Not sure how to combine the two into one.
The expected result should be like below. Please note there are some "category" in table1 but not in table2 or vice versa, for example category c and d.
table1 table2
a 4 2
b 4 3
c 3
d 4
One method is full join:
select coalesce(t1c.category, t2c.category) as category,
t1c.t1_cnt, t2c.t2_cnt
from (select category, count(*) as t1_cnt
from table1
group by category
) t1c full join
(select category, count(*) as t2_cnt
from table2
group by category
) t2c
on t1c.category = t2c.category;
You need to be very careful that you aggregate before doing the join.
Related
I have a table with id, Name columns.
When selecting I want to group by on Name column (but show all records NO summary), and show result count max number of in one grouping to min number of one grouping.
SELECT Table1.id, Table1.name
FROM Table1
GROUP BY Table1.id, Table1.name;
This is table:
My idea:
but I get this result:
One approach uses a join to a subquery which finds the counts for each name:
SELECT a.name, a.ID
FROM Table1 AS a
INNER JOIN
(
SELECT name, COUNT(*) AS cnt
FROM Table1
GROUP BY name
) AS b
ON a.name = b.name
ORDER BY
b.cnt DESC,
a.ID;
When you group by ID you create a separate group for each element, because each element has a unique ID. To get the count of each name group, you will want to create a grouping by name and then join it with your original table so the values are preserved. Something like:
WITH Counts (name, cnt) AS
(SELECT name, COUNT(*)
FROM Table1
GROUP BY name)
SELECT Table1.id, Table1.name
FROM Table1, Counts
INNER JOIN Counts
ON Table1.name = Counts.name
ORDER BY Counts.cnt DESC
Oh, I see. You an use a subquery in the order by:
select t.*
from t
order by (select count(*) from t t2 where t2.name = t.name) desc, name;
Note that name is the second order by key. If two names have the same counts, then this keeps all the rows for a given name together.
I have 2 databases in the same server and I need to compare the registers on each one, since one of the databases is not importing all the information
I was trying to do a ROW count but it's not working
Currently I am doing packages of 100,000 rows approximate, and lookup at them in Excel.
Let's say I want a query that does a count for each ID in TABLE A and then compares the count result VS TABLE B count for each ID, since they are the same ID the count should be the same, and I want that brings me the ID on which there where any mismatch between counts.
--this table will contain the count of occurences of each ID in tableA
declare #TableA_Results table(
ID bigint,
Total bigint
)
insert into #TableA_Results
select ID,count(*) from database1.TableA
group by ID
--this table will contain the count of occurences of each ID in tableB
declare #TableB_Results table(
ID bigint,
Total bigint
);
insert into #TableB_Results
select ID,count(*) from database2.TableB
group by ID
--this table will contain the IDs that doesn't have the same amount in both tables
declare #Discordances table(
ID bigint,
TotalA bigint,
TotalB bigint
)
insert into #Discordances
select TA.ID,TA.Total,TB.Total
from #TableA_Results TA
inner join #TableB_Results TB on TA.ID=TB.ID and TA.Total!=TB.Total
--the final output
select * from #Discordances
The question is vague, but maybe this SQL Code might help nudge you in the right direction.
It grabs the IDs and Counts of each ID from database one, the IDs and counts of IDs from database two, and compares them, listing out all the rows where the counts are DIFFERENT.
WITH DB1Counts AS (
SELECT ID, COUNT(ID) AS CountOfIDs
FROM DatabaseOne.dbo.TableOne
GROUP BY ID
), DB2Counts AS (
SELECT ID, COUNT(ID) AS CountOfIDs
FROM DatabaseTwo.dbo.TableTwo
GROUP BY ID
)
SELECT a.ID, a.CountOfIDs AS DBOneCount, b.CountOfIDs AS DBTwoCount
FROM DB1Counts a
INNER JOIN DB2Counts b ON a.ID = b.ID
WHERE a.CountOfIDs <> b.CountOfIDs
This SQL selects from the specific IDs using the "Database.Schema.Table" notation. So replace "DatabaseOne" and "DatabaseTwo" with the names of your two databases. And of course replace TableOne and TableTwo with the names of your tables (I'm assuming they're the same). This sets up two selects, one for each database, that groups by ID to get the count of each ID. It then joins these two selects on ID, and returns all rows where the counts are different.
You could full outer join two aggregate queries and pull out ids that are either missing in one table, or for which the record count is different:
select coalesce(ta.id, tb.id), ta.cnt, tb.cnt
from
(select id, count(*) cnt from tableA) ta
full outer join (select id, count(*) cnt from tableB) tb
on ta.id = tb.id
where
coalesce(ta.cnt, -1) <> coalesce(tb.cnt, -1)
You seem to want aggregation and a full join:
select coalesce(a.id, b.id) as id, a.cnt, b.cnt
from (select id, count(*) as cnt
from a
group by id
) a full join
(select id, count(*) as cnt
from b
group by id
) b
on a.id = b.id
where coalesce(a.cnt, 0) <> coalesce(b.cnt, 0);
I have below hive tables
Table_1
ID
1
1
2
Table_2
ID
1
2
2
I am comparing two tables based on count of ID in both tables, I need the output like below
ID
1 - 2records in table 1 and 1 record in Table 2
2 - one record in Table 1 and 2 records in table 2
Table_1 is parent table
i am using below query
select count(*),ID from Table_1 group by ID;
select count(*),ID from Table_2 group by ID;
Just do a full outer join on your queries with the on condition as X.id = Y.id, and then select * from the resultant table checking for nulls on either side.
Select id, concat(cnt1, " entries in table 1, ",cnt2, "entries in table 2") from (select * from (select count(*) as cnt1, id from table1 group by id) X full outer join (select count(*) as cnt2, id from table2 group by id)
on X.id=Y.id
)
Try This. You may use a case statement to check if it should be record / records etc.
SELECT m.id,
CONCAT (COALESCE(a.ct, 0), ' record in table 1, ', COALESCE(b.ct, 0),
' record in table 2')
FROM (SELECT id
FROM table_1
UNION
SELECT id
FROM table_2) m
LEFT JOIN (SELECT Count(*) AS ct,
id
FROM table_1
GROUP BY id) a
ON m.id = a.id
LEFT JOIN (SELECT Count(*) AS ct,
id
FROM table_2
GROUP BY id) b
ON m.id = b.id;
You could use this Python program to do a full comparison of 2 Hive tables:
https://github.com/bolcom/hive_compared_bq
If you want a quick comparison just based on counts, then pass the "--just-count" option (you can also specify the group by column with "--group-by-column").
The script also allows you to visually see all the differences on all rows and all columns if you want a complete validation.
I have two tables in Access, one containing IDs (not unique) and some Name and one containing IDs (not unique) and Location. I would like to return a third table that contains only the IDs of the elements that appear more than 1 time in either Names or Location.
Table 1
ID Name
1 Max
1 Bob
2 Jack
Table 2
ID Location
1 A
2 B
Basically in this setup it should return only ID 1 because 1 appears twice in Table 1 :
ID
1
I have tried to do a JOIN on the tables and then apply a COUNT but nothing came out.
Thanks in advance!
Here is one method that I think will work in MS Access:
(select id
from table1
group by id
having count(*) > 1
) union -- note: NOT union all
(select id
from table2
group by id
having count(*) > 1
);
MS Access does not allow union/union all in the from clause. Nor does it support full outer join. Note that the union will remove duplicates.
Simple Group By and Having clause should help you
select ID
From Table1
Group by ID
having count(1)>1
union
select ID
From Table2
Group by ID
having count(1)>1
Based on your description, you do not need to join tables to find duplicate records, if your table is what you gave above, simply use:
With A
as
(
select ID,count(*) as Times From table group by ID
)
select * From A where A.Times>1
Not sure I understand what query you already tried, but this should work:
select table1.ID
from table1 inner join table2 on table1.id = table2.id
group by table1.ID
having count(*) > 1
Or if you have ID's in one table but not the other
select table1.ID
from table1 full outer join table2 on table1.id = table2.id
group by table1.ID
having count(*) > 1
I have 2 tables and am trying to do one query to save myself some work.
Table 1: id, category id, colour
Table 2: category id, category name
I want to join them so that I get id, category id, category name, colour
Then I want to limit it so that no "red" items are selected (WHERE colour != "red")
Then I want to count the number of records in each category (COUNT(id) GROUP BY (category id).
I have been trying:
SELECT COUNT(table1.id), table1.category_id, table2.category_name
FROM table1
INNER JOIN table2 ON table1.category_id=table2.category_id
WHERE table1.colour != "red"
But it just doesn't work. I've tried lots of variations and just get no results when I try the above query.
You have to use GROUP BY so you will have multiple records returned,
SELECT COUNT(*) TotalCount,
b.category_id,
b.category_name
FROM table1 a
INNER JOIN table2 b
ON a.category_id = b.category_id
WHERE a.colour <> 'red'
GROUP BY b.category_id, b.category_name
SELECT COUNT(*), table1.category_id, table2.category_name
FROM table1
INNER JOIN table2 ON table1.category_id=table2.category_id
WHERE table1.colour <> 'red'
GROUP BY table1.category_id, table2.category_name
I have used sub-query and it worked great!
SELECT *,(SELECT count(*) FROM $this->tbl_news WHERE
$this->tbl_news.cat_id=$this->tbl_categories.cat_id) as total_news FROM
$this->tbl_categories