Got error in joining two tables: Left and right key variables 'Date' and 'Date' include cells containing non-string values.

Hi, I have two tables a and b. Both have a column Date as datenum. When I use left join, I got this error: "Left and right key variables 'Date' and 'Date' include cells containing non-string values." One table has 600 records; the other table is very large and has 25000 records. What can be the problem here and how to fix this?

Thanks for any input.

[KL]

what is left join?

[JFz]

I am using outerjoin:

outerjoin(a,b,'Type','left','MergeKeys',true);

Answer 1

[Peter Perkins]

The error seems clear: you are trying to use a variable that is not supported as a key. You say that you have a datenum variable, the error suggests that that is not the case, that you have a cell array containing datenums.

If you are using anything like a recent version of MATLAB, you will likely be better of using datetimes.

[JFz]

Thanks. I found out what the problem was: The keys were arrays of cells. I converted the cell array into array of doubles. I will post the answer soon.