Matlab select query incorrectly handling null

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Allan Brett
Allan Brett 2021-2-16
评论： Walter Roberson 2024-5-3
Running a simple mysql select query (select * from table) using the SELECT(CONN,QUERY) command. If I run the query through the command line I can view the data as expected. There are a few columns where every value is null which is correct for the data. If I run the query through the Matlab select command all row columns except one return as expected. One column instead of reading all NULL as it should, returns all -2147483648. Any help is appreciated.

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采纳的回答

Allan Brett
Allan Brett 2021-2-17
For those who run into this problem.
https://www.mathworks.com/help/database/ug/select.html
Go to section: Change Missing Values in Imported Data Using Vector Indexing

更多回答（1 个）

Fiza
Fiza 2024-5-3
编辑：Walter Roberson 2024-5-3
% Read the image
f=imread('f.jpg');
b=imread('f2.jpg');
%convert images to grayscale
if size(f,3)==3
f=rgb2gray(f);
end
if size(b,3)==3
b=rgb2gray(b);
end
% perform normalized cross-correlation
R=normxcorr2(f,b);
  2 个评论
Walter Roberson
Walter Roberson 2024-5-3
I don't understand how this solves the problem of what MATLAB returns for missing values in a database query?

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