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POSQL add table to "From" group, changes answer
 

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  1. POSQL add table to "From" group, changes answer
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    <p>I have a query that spits out a result:</p> <pre><code>Select Sum(Count(P.Create_Dtime)), From Player P Where Trunc(P.Create_Dtime) &gt;= To_Date('2012-mar-01','yyyy-mon-dd') And Trunc(P.Create_Dtime) &lt; To_Date('2015-sep-9','yyyy-mon-dd') Group By Trunc(P.Create_Dtime) Order By Trunc(P.create_Dtime) Asc </code></pre> <p>Result = 317827</p> <p>Now,when I change this query to add another table to the from group (i will be adding constraints based on this table later on)...the result spits out a new answer with a sum much larger than the original. For example, the original answer was 317827, and now when I add in the table below, the answer comes out to 6356540, exactly 20x the original answer. There are 20 rows of data in the "Feature_group_xref" table, and the create_dtime column is also in that table. Why are these values multiplying? I assumed that because i have identified each column (with "P") that it shouldn't be a problem. Any suggestions? If you see below the only thing I added was a new table name:</p> <pre><code>Select Sum(Count(P.Create_Dtime)) From Player P, Feature_group_xref X Where Trunc(P.Create_Dtime) &gt;= To_Date('2012-mar-01','yyyy-mon-dd') And Trunc(P.Create_Dtime) &lt; To_Date('2015-sep-9','yyyy-mon-dd') Group By Trunc(P.Create_Dtime) Order By Trunc(P.create_Dtime) Asc </code></pre> <p>Result = 6356540 (There are 20 rows in table "Feature_Group_Xref" and one column is create_dtime. This result is exactly 20x the result in the first query.</p> <p>**UPDATE - I have this query which gives me the sum of active players within the last 7 days for users created after march 1 2012...</p> <pre><code>Select sysdate,sum(Count(p.init_dtime)) From Player p Where Trunc(p.Init_Dtime) &gt; Trunc(Sysdate) - 7 And Trunc(P.Create_Dtime) &gt;= To_Date('2012-mar-01','yyyy-mon-dd') And Trunc(P.Create_Dtime) &lt; To_Date('2015-sep-9','yyyy-mon-dd') Group By Trunc(P.Init_Dtime) Order By Trunc(p.Init_Dtime) Asc </code></pre> <p>I want to take this query and break it down so that the only (init_dtime) values that show up are the ones where group_id = 1,10,20,30, and 40 (Group ids are 1-100). Group ID can be found in the player_source table, and the column "player_id" is located in both the player and player_source table if that helps.</p>
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    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USAmerico
    1. USAmerico
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    2. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. COwhat you get in the second fragment is the carthesian product of P*X: you get the original result **for every row of X** For the aggregates, this means that the sum/count is multiplied by the number of tuples in X, min/max of course stay the same.
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      1. POSQL add table to "From" group, changes answer
      1. USwildplasser
    2. COYou should use Joins instead of Cartesian Product.
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      1. POSQL add table to "From" group, changes answer
      1. USdjadmin
 

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