CODEWITHSUNDEEP
mysql
Chrisvdberge
Chrisvdberge

Reputation: 1956

Sum multiple counts from multiple tables

I have different tables (per region) with some columns that are the same. Now I need to have a count for each value that is placed in one column over multiple tables. I'm trying to get a sum for this so I don't have to use 4 separate queries and outputs. Furthermore the values are matched with a lookup table

Region table(s) - Table1:

    id       | Column1 | 
    ---------|----------|
    1        | 1
    2        | 2
    3        | 3
etc

Lookup table

    id       | Description | 
    ---------|-------------|
    1        | Description1
    2        | Description2
    3        | Description3

The query I'm using to get the count from 1 of the tables is :

SELECT Description, Count(*) as Number from Table1, LookupTable 
WHERE Column1 = LookupTable.id GROUP BY Column1 ORDER BY Number Desc

The output is 

 Description   | Number
---------------|--------
Description1   | Number
Description2   | Number
Etc.

Any idea on how to sum up the counts for each Description/value of Column1 from 4 tables that generates the output as displayed above (but then with the sum value for each description)?

Upvotes: 1

Views: 171

Answers (2)

valex
valex

Reputation: 24134

It's not clear but I guess you can use:

select LookupTable.id,LookupTable.Description, SUM(Cnt) as Number 
from LookupTable

JOIN
(
    SELECT Column1 as CId, count(*) as Cnt from Table1 group by Column1
    union all
    SELECT Column2 as CId, count(*) as Cnt from Table2 group by Column2
    union all
    SELECT Column3 as CId, count(*) as Cnt from Table3 group by Column3
    union all
    SELECT Column4 as CId, count(*) as Cnt from Table4 group by Column4
) T1 on LookupTable.id =T1.Cid
 GROUP BY LookupTable.id,LookupTable.Description
 ORDER BY Number Desc

Upvotes: 2

Code Lღver
Code Lღver

Reputation: 15603

Use this query:

SELECT LookupTable.Description, Count(*) as Number 
   FROM Table1, LookupTable 
      WHERE Table1.Column1 = LookupTable.id 
          GROUP BY Table1.Column1;

You have leave the name of table or its alias to call the column.

Upvotes: 0

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