MATLAB: How to retrieve the exact value of a BIGINT from the database into MATLAB using Database Toolbox 3.5 (R2008b)

Database Toolbox

I have a database with a column (col1) containing BIGINTs. On one of the rows I have the number 12345678901234567 and on another 98765432104567895. If I try to get this number as int64 into MATLAB however I loose precision:
>> setdbprefs('DataReturnFormat','cellarray');
>> conn = database('myDatabase','myUser','myPassword');
>> res = exec(conn,'SELECT col1 FROM myTable');
>> res = fetch(res);
>> data = res.data;
>> int64(res.data{1})
ans =
      12345678901234568
  >> int64(res.data{2})
  ans =
      98765432104567888

Best Answer

To get the BIGINT data as INT64 into MATLAB you can retrieve the number as text data and then use the attached MEX-file below to convert to INT64.
To retrieve the data as text you could consider changing the actual data format in your database or you could simply include a CAST in your query:
>> setdbprefs('DataReturnFormat','cellarray');
>> conn = database('myDatabase','myUser','myPassword');
>> res = exec(conn,'SELECT CAST(col1 AS VARCHAR) FROM myTable');
>> res = fetch(res);
>> data = res.data;
>> longlong = atoi64(data(:,1))
longlong =
      12345678901234567
      98765432104567895
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