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Trying to make Java method to get the length of a column

Joel Christophel
Ranch Hand

Joined: Apr 20, 2011
Posts: 245
    
    1

Here's what I've tried. The 'rs' variable references a ResultSet object, and the 'meta' variable references a DatabaseMetaData object.



The column I'm trying to access contains 3 rows with the values being "Joel", "Hannah", and "Kevin. Since I'm trying to get the size of the column, my desired return value would be 3, but it's returning 25.
Bear Bibeault
Author and ninkuma
Marshal

Joined: Jan 10, 2002
Posts: 63053
    
  69

That's because the size of a column is its length. It has nothing whatsoever to do with the number of rows.

In fact, the number of rows has nothing at all to do with a specific column but the table as a whole.

If you want to get the number of rows, you'd do that with a SELECT COUNT(*) statement.


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Rob Spoor
Sheriff

Joined: Oct 27, 2005
Posts: 20049
    
  30

If you want to exclude records with NULL values you should replace that COUNT(*) with COUNT(name_of_column).


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Joel Christophel
Ranch Hand

Joined: Apr 20, 2011
Posts: 245
    
    1

Thanks for the help; it now returns 3. My new method:

 
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