How to check whether a column exist in a table?

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Alon Rozen
Alon Rozen el 24 de Nov. de 2016
Comentada: Nachiket Wadwankar el 9 de Feb. de 2024
Hi all,
I search for this question in the web and found the following solution: Suppose I have a table named 'My_Table' and want to check if it contains a column (field) named 'My_Column'. The code:
Exist_Column = strmatch('My_Column',My_Table.Properties.VariableNames)
should result in logical that answer the question. I checked it and it works. However, the Matlab editor commented that 'strmatch' is not a recommended function to use because it is about to be removed in future version and suggest instead the use of either 'strncmp' or 'validatestring'. Problem is that both do not return a logical and more steps are required to get the answer.
So, my question is: what is the simplest recommended way to determine if a certain column name exist in a table?
Thanks,
Alon
  1 comentario
Carlos Aguilar
Carlos Aguilar el 31 de Dic. de 2017
Just came across to this question. An anonymous function will also do the job (and will be reusable within the scope):
isTableCol = @(t, thisCol) ismember(thisCol, t.Properties.VariableNames);

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Respuesta aceptada

KSSV
KSSV el 24 de Nov. de 2016
Exist_Column = strcmp('My_Column',My_Table.Properties.VariableNames)
val = Exist_Column(Exist_Column==1) ;
  6 comentarios
Gabriel Blanco
Gabriel Blanco el 25 de Jun. de 2019
Bonjour Nic!
Nikolaus Koopmann
Nikolaus Koopmann el 29 de Nov. de 2022
any("MyColumn" == string(My_Table.Properties.VariableNames))

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Más respuestas (2)

jkr
jkr el 14 de Mayo de 2019
sum(ismember(mx.Properties.VariableNames,'NameYouWantToCheck'))
returns 1 if found, 0 if not
  2 comentarios
AusPollen
AusPollen el 23 de Mayo de 2021
Nice! although you don't need to sum if you switch the ismember arguments, ie. use ismember('My_Column',My_Table.Properties.VariableNames)
Nachiket Wadwankar
Nachiket Wadwankar el 9 de Feb. de 2024
This is exactly what I wanted. Thanks a lot for this trick!!

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Sean Lynch
Sean Lynch el 5 de Sept. de 2021
I used "any", but agree "ismember" is even better
exists = any(strcmp('Column-Name', My_Table.Properties.VariableNames))

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