Subtraction between two sql queries

Question

I have 2 queries in MS SQL that return a number of results using the COUNT function.

I can run the the first query and get the first result and then run the other on

Answer 1

SELECT (count(*) from t1) - (count(*) from t2);

this worked for me.

Also if there is only one table you can also do:

SELECT (count(column1)) - count(column2)) from table; 

Answer 2

I know this is an old post but here is another solution that fit best to my needs (tested on firebird)

SELECT c1-c2 from (select count(*) c1 from t1), (SELECT COUNT(*) c2 from t2);

Answer 3

This can be done in a single query:

SELECT COUNT(col_name) - COUNT(DISTINCT col_name) as Difference from table_name;

Answer 4

SELECT (SELECT COUNT(*) FROM t1) - (SELECT COUNT(*) FROM t2)

Answer 5

Just create an inline function with your query logic, and have it return the result. Pass in parameters as needed.

Answer 6

SELECT
   t1.HowManyInTable1
  ,t2.HowManyInTable2
  ,t1.HowManyInTable1 = t2.HowManyInTable2  Table1_minus_Table2
 from (select count(*) HowManyInTable1 from Table1) t1
  cross join (select count(*) HowManyInTable2 from Table2) t2