Errors in SQL Server while importing CSV file despite varchar(MAX) being used for each column

In SQL Server Import and Export Wizard you can adjust the source data types in the Advanced tab (these become the data types of the output if creating a new table, but otherwise are just used for handling the source data).

The data types are annoyingly different than those in MS SQL, instead of VARCHAR(255) it's DT_STR and the output column width can be set to 255. For VARCHAR(MAX) it's DT_TEXT.

So, on the Data Source selection, in the Advanced tab, change the data type of any offending columns from DT_STR to DT_TEXT (You can select multiple columns and change them all at once).

This answer may not apply universally, but it fixed the occurrence of this error I was encountering when importing a small text file. The flat file provider was importing based on fixed 50-character text columns in the source, which was incorrect. No amount of remapping the destination columns affected the issue.

To solve the issue, in the "Choose a Data Source" for the flat-file provider, after selecting the file, a "Suggest Types.." button appears beneath the input column list. After hitting this button, even if no changes were made to the enusing dialog, the Flat File provider then re-queried the source .csv file and then correctly determined the lengths of the fields in the source file.

Once this was done, the import proceeded with no further issues.

I think its a bug, please apply the workaround and then try again: http://support.microsoft.com/kb/281517.

Also, go into Advanced tab, and confirm if Target columns length is Varchar(max).