I have TableA of, say, 3000 rows (could be any number < 10000). I need to create TableX with 10000 rows. So I need to select random 10000 - (number of rows in TableA) from TableB (and add in TableA as well) to create TableX. Any ideas please?
Something like this (which obviously wouldnt work):
Create table TableX as
select * from TableA
union
select * from TableB limit (10000 - count(*) from TableA);
You could use union all and window functions. You did not list the table columns, so I assumed col1 and col2:
insert into tableX (col1, col2)
select col1, col2 from table1
union all
select t2.col1, t2.col2
from (select t2.*, row_number() over(order by random()) from table2 t2) t2
inner join (select count(*) cnt from table1) t1 on t2.rn <= 10000 - t1.cnt
The first query in union all selects all rows from table1. The second query assigns random row numbers to rows in table2, and then selects as many rows as needed to reach a total of 10000.
Actually it might be simpler to select all rows from both tables, then order by and limit in the outer query:
insert into tableX (col1, col2)
select col1, col2
from (
select col1, col2, 't1' which from table1
union all
select col1, col2, 't2' from table2
) t
order by which, random()
limit 10000
with inparms as (
select 10000 as target_rows
), acount as (
select count(*) as acount, inparms.target_rows
from tablea
cross join inparms
), btag as (
select b.*, 'tableb' as tabsource,
row_number() over (order by random()) as rnum
from tableb
)
select a.*, 'tablea', row_number() over (order by 1) as rnum
from tablea
union all
select b.*
from btag b
join acount a on b.rnum <= a.target_rows - a.acount
;
I have a sql statement that will give me two columns from two tables using sub query.
select
sum(field1) as f1_sum,
(select sum(field2) from table2) as f2_sum
from
table1
group by
table1.field_x
I want to get the total of f1_sum + f2_sum as the third column output from this query. It seems simple but I can't find a way around this.Question is how to get the sum of sum fields.
I am ok to write SP or a view to do this etc..
Can someone assist please ?
you can use subquery like:
SELECT t1.f1_sum+t1.f2_sum AS total_sum FROM
(select sum(field1) as f1_sum , (select sum(field2) from table2) as f2_sum
from table1
group by table1.field_x) AS t1
I would suggest doing it like this:
select t1.f1_sum, t2.f2_sum, coalesce(t1.f1_sum, 0) + coalesce(t2.f2_sum, 0)
from (select sum(field1) as f1_sum
from table1 t1
group by t1.field_x
) t1 cross join
(select sum(field2) as f2_sum from table2) t2;
When possible, I prefer to keep table references in the from clause. I added the coalesce() just in case any of the values could be NULL.
You could also try this :
SELECT SUM(a.field1) f1_sum,
SUM(b.field2) f2_sum,
(SUM(a.field1) + SUM(b.field2)) f3_sum
from table1 a, table2 b
Simply you can write,
select sum(field1) as f1_sum
, (select sum(field2) from table2) as f2_sum
, (ISNULL(sum(field1),0) + ISNULL((select sum(field2) from table2),0)) AS Total_Sum
from table1
group by table1.field_x
I need to count rows in more than one table in SQL Server 2008. I do this:
select count(*) from (select * from tbl1 union all select * from tbl2)
But it gives me an error of incorrect syntax near ). Why?
PS. The actual number of tables can be more than 2.
In case you have different number of columns in your tables try this way
SELECT count(*)
FROM (
SELECT NULL as columnName
FROM tbl1
UNION ALL
SELECT NULL
FROM tbl2
) T
try this:
You have to give a name to your derived table
select count(*) from
(select * from tbl1 union all select * from tbl2)a
I think you have to alias the SELECT in the FROM clause:
select count(*)
from
(
select * from tbl1
union all
select * from tbl2
) AS SUB
You also need to ensure that the * in both tables tbl1 and tbl2 return exactly the same number of columns and they have to be matched in their type.
I don't like doing the union before doing the count. It gives the SQL optimizer an opportunithy to choose to do more work.
AlexK's (deleted) solution is fine. You could also do:
select (select count(*) from tbl1) + (select count(*) from tbl2) as cnt
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