Related
I need to select the newest row from two tables, two tables have the same schema
Table A and Table B is the same schema, like this:
Table A :
user_id, time_stamp, order_id
1,20190101,100
2,20190103,201
3,20190102,300
5,20180209,99
Table B:
user_id, time_stamp, order_id
1,20190102,101
2,20190101,200
3,20190103,305
4,20190303,900
I want the output is A union B, then select the newer row of a user, order by time_stamp:
output should be:
1,20190102,101
2,20190103,201
3,20190103,305
4,20190303,900
5,20180209,99
How to write this SQL?
You can write as following sample query demo
with unionedTable as (
select * from tableA
union
select * from tableB)
,newerUsersTable as (
select distinct on (u.user_id)u.*
from unionedTable u
order by u.user_id, u.time_stamp desc
)select * from newerUsersTable
The main idea is using FULL OUTER JOIN among two tables, and then using UNION [ALL] for returning data set. So, consider the following SELECT statement with WITH clause :
with a( user_id, time_stamp, order_id ) as
(
select 1,20190101,100 union all
select 2,20190103,201 union all
select 3,20190102,300 union all
select 5,20180209,99
), b( user_id, time_stamp, order_id ) as
(
select 1,20190102,101 union all
select 2,20190101,200 union all
select 3,20190103,305 union all
select 4,20190303,900
), c as
(
select a.user_id as user_id_a, a.time_stamp as time_stamp_a, a.order_id as order_id_a,
b.user_id as user_id_b, b.time_stamp as time_stamp_b, b.order_id as order_id_b
from a full outer join b
on a.user_id = b.user_id
), d as
(
select user_id_a, time_stamp_a, order_id_a
from c
where coalesce(time_stamp_b,time_stamp_a) <= time_stamp_a
union all
select user_id_b, time_stamp_b, order_id_b
from c
where time_stamp_b >= coalesce(time_stamp_a,time_stamp_b)
)
select user_id_a as user_id, time_stamp_a as time_stamp, order_id_a as order_id
from d
order by user_id_a;
user_id time_stamp order_id
1 20190102 101
2 20190103 201
3 20190103 305
4 20190303 900
5 20180209 99
Demo
Use Group by(user_id) to show all user_id
Use max(time_stamp) get the newer row of user
SELECT aa.* from (select * from a union SELECT * from b ) aa
JOIN
(select user_id,max(time_stamp) as new_time
from (select * from a union SELECT * from b ) u
group by u.user_id) bb
on bb.new_time=aa.time_stamp and bb.user_id=aa.user_id
order by aa.user_id;
SQL Fiddle
I would simply do:
select user_id, time_stamp, order_id
from (select ab.*,
row_number() over (partition by user_id order by time_stamp desc) as seqnum
from (select a.* from a union all
select b.* from b
) ab
) ab
where seqnum = 1;
I wrote this query but it does not work as I expected.
1st Goal: select rows that have repeated in certain columns and return whole columns.
2nd Goal: Update a flag (a column) to identify which records have repeated.
Could you please help me?
SELECT
*
FROM AvvalV2NS AS M
WHERE EXISTS
(SELECT
M.Astate,
M.Acity,
M.Azone,
M.Abvillage,
M.Avillage,
COUNT(*)
FROM AvvalV2NS AS M
GROUP BY M.Astate,
M.Acity,
M.Azone,
M.Abvillage,
M.Avillage
HAVING COUNT(*) > 1)
If you want to get the rows that are duplicated, window functions are probably the easiest way:
select a.*
from (select a.*,
count(*) over (partition by M.Astate, M.Acity, M.Azone, M.Abvillage, M.Avillage) as cnt
from AvvalV2NS a
) a
where cnt > 1;
You can update a flag by doing something like this:
with toupdate as (
select a.*
from (select a.*,
count(*) over (partition by M.Astate, M.Acity, M.Azone, M.Abvillage, M.Avillage) as cnt
from AvvalV2NS a
) a
)
update toupdate
set isduplicate = (case when cnt > 1 then 1 else 0 end);
Suppose your table have an id column:
SELECT * FROM THE_TABLE WHERE ID IN (
SELECT ID FROM
(SELECT ID, REPEATING_COLUMNS, COUNT(*) FROM THE_TABLE GROUP BY REPEATING_COLUMNS HAVING COUNT(*) > 1)
)
UPDATE THE_TABLE SET THE_FLAG = "HERE WE GO" WHERE ID IN (
SELECT ID FROM
(SELECT ID, REPEATING_COLUMNS, COUNT(*) FROM THE_TABLE GROUP BY REPEATING_COLUMNS HAVING COUNT(*) > 1)
)
Hope this helps.
I'm trying to pull ALL fields and records if two of the fields (category and measure) create 3 or more dups.
SELECT category
,measure
,date
FROM my_table
for example:
category measure date
EVENTS COL 04/15/2014
EVENTS COL 05/21/2014
EVENTS COL 07/16/2014
So the above meets the criteria of 3 or more so we would pull all three.
category measure rec_count
EVENTS COL 3
I think you want something like - gives you all rows with 3 or more records
SELECT
category,
measure,
date
FROM
my_table t1
inner join (
SELECT
category,
measure
FROM
my_table
group by
category,
measure
having
count(*) >= 3
) t2 on
t2.category = t1.category and
t2.measure = t1.measure
To get only the count you would run
SELECT
category,
measure
count(*)
FROM
my_table
group by
category,
measure
having
count(*) >= 3
Sounds like you're looking for GROUP BY:
SELECT category
,measure
,count(*) as rec_count
FROM my_table
GROUP BY category, measure
HAVING count(*) >= 3
SELECT
category, measure, date, count(*) cnt
FROM my_table
GROUP BY category, measure
HAVING cnt >= 3
;
This will not group your results.
SELECT q.* FROM
(SELECT
category
,measure
,date
,COUNT(*) OVER(PARTITION BY category,measure) [rec_count]
FROM
my_table) q
WHERE q.rec_count >= 3
What is the method in T-SQL to select the orginal values limited by a HAVING attribute. For example, if I have
A|B
10|1
11|2
10|3
How would I get all the values of B (Not An Average or some other summary stat), Grouped by A, having a Count (Occurrences of A) greater than or equal two 2?
Actually, you have several options to choose from
1. You could make a subquery out of your original having statement and join it back to your table
SELECT *
FROM YourTable yt
INNER JOIN (
SELECT A
FROM YourTable
GROUP BY
A
HAVING COUNT(*) >= 2
) cnt ON cnt.A = yt.A
2. another equivalent solution would be to use a WITH clause
;WITH cnt AS (
SELECT A
FROM YourTable
GROUP BY
A
HAVING COUNT(*) >= 2
)
SELECT *
FROM YourTable yt
INNER JOIN cnt ON cnt.A = yt.A
3. or you could use an IN statement
SELECT *
FROM YourTable yt
WHERE A IN (SELECT A FROM YourTable GROUP BY A HAVING COUNT(*) >= 2)
A self join will work:
select B
from table
join(
select A
from table
group by 1
having count(1)>1
)s
using(A);
You can use window function (no joins, only one table scan):
select * from (
select *, cnt=count(*) over(partiton by A) from table
) as a
where cnt >= 2
How can I select count(*) from two different tables (call them tab1 and tab2) having as result:
Count_1 Count_2
123 456
I've tried this:
select count(*) Count_1 from schema.tab1 union all select count(*) Count_2 from schema.tab2
But all I have is:
Count_1
123
456
SELECT (
SELECT COUNT(*)
FROM tab1
) AS count1,
(
SELECT COUNT(*)
FROM tab2
) AS count2
FROM dual
As additional information, to accomplish same thing in SQL Server, you just need to remove the "FROM dual" part of the query.
Just because it's slightly different:
SELECT 'table_1' AS table_name, COUNT(*) FROM table_1
UNION
SELECT 'table_2' AS table_name, COUNT(*) FROM table_2
UNION
SELECT 'table_3' AS table_name, COUNT(*) FROM table_3
It gives the answers transposed (one row per table instead of one column), otherwise I don't think it's much different. I think performance-wise they should be equivalent.
My experience is with SQL Server, but could you do:
select (select count(*) from table1) as count1,
(select count(*) from table2) as count2
In SQL Server I get the result you are after.
Other slightly different methods:
with t1_count as (select count(*) c1 from t1),
t2_count as (select count(*) c2 from t2)
select c1,
c2
from t1_count,
t2_count
/
select c1,
c2
from (select count(*) c1 from t1) t1_count,
(select count(*) c2 from t2) t2_count
/
select
t1.Count_1,t2.Count_2
from
(SELECT count(1) as Count_1 FROM tab1) as t1,
(SELECT count(1) as Count_2 FROM tab2) as t2
A quick stab came up with:
Select (select count(*) from Table1) as Count1, (select count(*) from Table2) as Count2
Note: I tested this in SQL Server, so From Dual is not necessary (hence the discrepancy).
For a bit of completeness - this query will create a query to give you a count of all of the tables for a given owner.
select
DECODE(rownum, 1, '', ' UNION ALL ') ||
'SELECT ''' || table_name || ''' AS TABLE_NAME, COUNT(*) ' ||
' FROM ' || table_name as query_string
from all_tables
where owner = :owner;
The output is something like
SELECT 'TAB1' AS TABLE_NAME, COUNT(*) FROM TAB1
UNION ALL SELECT 'TAB2' AS TABLE_NAME, COUNT(*) FROM TAB2
UNION ALL SELECT 'TAB3' AS TABLE_NAME, COUNT(*) FROM TAB3
UNION ALL SELECT 'TAB4' AS TABLE_NAME, COUNT(*) FROM TAB4
Which you can then run to get your counts. It's just a handy script to have around sometimes.
As I can't see any other answer bring this up.
If you don't like sub-queries and have primary keys in each table you can do this:
select count(distinct tab1.id) as count_t1,
count(distinct tab2.id) as count_t2
from tab1, tab2
But performance wise I believe that Quassnoi's solution is better, and the one I would use.
SELECT (SELECT COUNT(*) FROM table1) + (SELECT COUNT(*) FROM table2) FROM dual;
Here is from me to share
Option 1 - counting from same domain from different table
select distinct(select count(*) from domain1.table1) "count1", (select count(*) from domain1.table2) "count2"
from domain1.table1, domain1.table2;
Option 2 - counting from different domain for same table
select distinct(select count(*) from domain1.table1) "count1", (select count(*) from domain2.table1) "count2"
from domain1.table1, domain2.table1;
Option 3 - counting from different domain for same table with "union all" to have rows of count
select 'domain 1'"domain", count(*)
from domain1.table1
union all
select 'domain 2', count(*)
from domain2.table1;
Enjoy the SQL, I always do :)
select (select count(*) from tab1) count_1, (select count(*) from tab2) count_2 from dual;
--============= FIRST WAY (Shows as Multiple Row) ===============
SELECT 'tblProducts' [TableName], COUNT(P.Id) [RowCount] FROM tblProducts P
UNION ALL
SELECT 'tblProductSales' [TableName], COUNT(S.Id) [RowCount] FROM tblProductSales S
--============== SECOND WAY (Shows in a Single Row) =============
SELECT
(SELECT COUNT(Id) FROM tblProducts) AS ProductCount,
(SELECT COUNT(Id) FROM tblProductSales) AS SalesCount
If the tables (or at least a key column) are of the same type just make the union first and then count.
select count(*)
from (select tab1key as key from schema.tab1
union all
select tab2key as key from schema.tab2
)
Or take your satement and put another sum() around it.
select sum(amount) from
(
select count(*) amount from schema.tab1 union all select count(*) amount from schema.tab2
)
Declare #all int
SET #all = (select COUNT(*) from tab1) + (select count(*) from tab2)
Print #all
or
SELECT (select COUNT(*) from tab1) + (select count(*) from tab2)
JOIN with different tables
SELECT COUNT(*) FROM (
SELECT DISTINCT table_a.ID FROM table_a JOIN table_c ON table_a.ID = table_c.ID );
SELECT (
SELECT COUNT(*)
FROM tbl1
)
+
(
SELECT COUNT(*)
FROM tbl2
)
as TotalCount
If you're using Google BigQuery this will work.
SELECT
date,
SUM(Table_1_Id_Count) AS Table_1_Id_Count,
SUM(Table_2_Id_Count) AS Table_2_Id_Count
FROM
(
SELECT
Id AS Table_1_Id,
date,
COUNT(Id) AS Table_1_Id_Count,
0 AS Table_2_Id_Count
FROM
`your_project_name.Table_1`
GROUP BY
Id,
date
UNION ALL
SELECT
Id AS Table_2_Id,
date,
0 AS Table_1_Id_Count,
COUNT(Id) AS Table_2_Id_Count
FROM
`your_project_name.Table_2`
GROUP BY
Id,
date
)
GROUP BY
date
select
(select count() from tab1 where field like 'value') +
(select count() from tab2 where field like 'value')
count
select #count = sum(data) from
(
select count(*) as data from #tempregion
union
select count(*) as data from #tempmetro
union
select count(*) as data from #tempcity
union
select count(*) as data from #tempzips
) a