Error: Cell contents reference from a non cell array object.

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Monisha
Monisha 2014-3-2
编辑： John Kelly 2015-2-27
I am using the following matlab code for selecting a particular row which matches a columnname from an access database. Once the row is retrieved , i try to store the values in a cell array .But i get an error when i try to print it.
q=FileNamevalue;
conn1=database('Dbname','','');
fna=exec(conn1,'select * from table1 where ImageName="',q,'"');
fna=fetch(fna);
fda=fna.data;
C = fda.'; %storing data in a cell array.
sprintf('ImageNo:%d\nImageName:%s\nDiseaseCategory: %s',C{1,1},C{2,1},C{3,1})
And here is the error: ??? Cell contents reference from a non-cell array object.
Error in ==> featurecomparison at 7 sprintf('IMAGENO:%d"\n"IMAGE NAME:%s"\n"DISEASE CATEGORY:%s"\n'); %Assumed to have 3 columns.
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Image Analyst
Image Analyst 2014-3-2
And you forgot to post your error message. Post ALL the red text . Don't snip out just part of it or paraphrase it, give us the whole thing.

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回答（3 个）

Image Analyst
Image Analyst 2014-3-2
What is the class of fda? Is it a cell array? What does this show if you put it just before the line that throws an error
whos fda
class(fda)
My guess is that fda is not a cell and so C is not a cell either, and then when you try to do C{1,1} it gives you the error because in order to use braces C must be a cell, which it is not .
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Monisha
Monisha 2014-3-9
@dpb @Image Analyst: I made another try using normal matlab cell operations and finally it worked. Sorry for not responding well and thanks for your valuable suggestions.

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dpb
dpb 2014-3-2
Taking a chance with the crystal orb...
C = fda.'; %storing data in a cell array.
Excepting it isn't--you forgot the curlies...
C = {fda.'};
in which case it appears you might just as well have written
C={fna.data};
dpb
dpb 2014-3-8
编辑：John Kelly 2015-2-27
...
fname=fetch(fname,10);
...
OK, from the database documentation for fetch one finds...
When fetch returns a cursor object, you can run many other functions, such as get and rows. To import data into the MATLAB workspace without metadata, use fetch with a database connection object as the input argument.
So, since we now know that fname is an object, we have to use the methods defined for that object.
See
http://www.mathworks.com/help/database/ug/importing-data-using-the-fetch-function.html
and the links therefrom to get and joy should then ensue.

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