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

In one of the INSERT statements you are attempting to insert a too long string into a string (varchar or nvarchar) column.

If it's not obvious which INSERT is the offender by a mere look at the script, you could count the <1 row affected> lines that occur before the error message. The obtained number plus one gives you the statement number. In your case it seems to be the second INSERT that produces the error.

From @gmmastros's answer

Whenever you see the message....

string or binary data would be truncated

Think to yourself... The field is NOT big enough to hold my data.

Check the table structure for the customers table. I think you'll find that the length of one or more fields is NOT big enough to hold the data you are trying to insert. For example, if the Phone field is a varchar(8) field, and you try to put 11 characters in to it, you will get this error.

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 :)

I had this issue although data length was shorter than the field length. It turned out that the problem was having another log table (for audit trail), filled by a trigger on the main table, where the column size also had to be changed.