[sql] error, string or binary data would be truncated when trying to insert

Just want to contribute with additional information: I had the same issue and it was because of the field wasn't big enough for the incoming data and this thread helped me to solve it (the top answer clarifies it all).

BUT it is very important to know what are the possible reasons that may cause it.

In my case i was creating the table with a field like this:

Select '' as  Period, * From Transactions Into #NewTable

Therefore the field "Period" had a length of Zero and causing the Insert operations to fail. I changed it to "XXXXXX" that is the length of the incoming data and it now worked properly (because field now had a lentgh of 6).

I hope this help anyone with same issue :)