Concatenate vertically multiple tables with different dimensions

I'd like to concatenate vertically several tables with common and uncommon columns: in this example code columns is common to A and B but not the others. The example expected result is C. In this example Type doesnt exist for A, then in C it is replaced by Nan. In my example, there are only 2 tables with one common column. I need to do this for 8 tables with 3 common columns and 5-7 columns in total.

A =

  3×2 table

    code      Name               
    ____    _________     
    1001    {'Jones'} 
    1002    {'James'}
    1001    {'Robert'}
    
B =

  3×2 table

    code      Type      
    ____    _________    
    201    {'Car'}    
    201    {'Bus'}  
    203    {'Train'}  
    
C = code      Name              Type          
    ____    _________        _________
    1001    {'Jones'}           Nan
    1002    {'James'}           Nan
    1001    {'Robert'}          Nan
    201       Nan              {'Car'}    
    201       Nan              {'Bus'}  
    203       Nan              {'Train'} 

Answer 1

[the cyclist]

You can do this with the outerjoin command:

A = table([1001; 1002; 1003],{'Jones';'James';'Robert'},...
        'VariableNames',{'code','Name'});

B = table([201; 202; 203],{'Car'; 'Bus'; 'Train'},...
         'VariableNames',{'code' 'Type'});

outerjoin(A,B,'MergeKeys',true)

ans = 6x3 table
    code       Name          Type   
    ____    __________    __________

     201    {0×0 char}    {'Car'   }
     202    {0×0 char}    {'Bus'   }
     203    {0×0 char}    {'Train' }
    1001    {'Jones' }    {0×0 char}
    1002    {'James' }    {0×0 char}
    1003    {'Robert'}    {0×0 char}

Because the variables with missing values are character type, MATLAB will leave them as empty character arrays. (It would have used NaN for missing numeric variables.)

[John Taylor]

Thanks a lot, but what if there are same values in the common column?

A = 
    code      Name               
    ____    _________     
    201    {'Jones'} 
   
B =    
    code      Type      
    ____    _________    
    201    {'Car'}    

I dont want them to be joined, just really one below the other:

C = 
    code      Name              Type          
    ____    _________        _________
    201    {'Jones'}           Nan
    201     Nan               {'Car'}

[the cyclist]

Ah, sorry. I assume you wanted to merge data. I believe that to simply concatenate them, you'll need to add the "missing" columns to each table. For example:

A = table([1001; 1002; 1003; 201],{'Jones';'James';'Robert';'Nancy'},...
        'VariableNames',{'code','Name'});

B = table([201; 202; 203],{'Car'; 'Bus'; 'Train'},...
         'VariableNames',{'code' 'Type'});

% Add new columns corresponding to the missing ones
A.Type = cell(size(A,1),1);
B.Name = cell(size(B,1),1);

C = [A; B]

C = 7x3 table
    code        Name            Type    
    ____    ____________    ____________

    1001    {'Jones'   }    {0×0 double}
    1002    {'James'   }    {0×0 double}
    1003    {'Robert'  }    {0×0 double}
     201    {'Nancy'   }    {0×0 double}
     201    {0×0 double}    {'Car'     }
     202    {0×0 double}    {'Bus'     }
     203    {0×0 double}    {'Train'   }

I just did the laziest way I could think of to add "empty" data. You could do other things.

[John Taylor]

All good, thank you!