If the first row was not string, and first value was double, then any string later will be null

[JawadJaber]

See this stackoverflow case https://stackoverflow.com/a/28862382/4516125

[Bosti1904]

I have the same problem. Suggestion: When defining the mapping you could also specify a type to which the mapping should "convert" or extend the transformations in that way.

[JawadJaber]

Can you show me an example? Mapping does not work for me.

[Bosti1904]

My previous comment is not relevant, becasue OleDbDataAdapter "decides" what data types are the columns going to be. Based on my research you can't define a columns's data type when reading from excel (I have downloaded the solution in debugged it and seen how the dataadapter works). Normally it analyses the first 8 rows and defines the data type based on the pattern from this rows. You could change the number of how many rows should he read in the registry but I do not garanty that will work.

In my case there where 3 rows empty, then one had a number and the 5 where empty and the one had a string. So the adapter defined the column as a number which was wrong. The only thing that seem to work for me was to define the cell/column type from "general" to "text", then all the values where read as string.

[JawadJaber]

Thank you very much, this conversion from "general" to "text" worked well with me

[Kavya27]

Is any other solution for this? that done by some setting in code.