I have a database table on a development server that is now fully populated after I set it running with an import routine for a CSV file containing 1.4 million rows.
use the sqlcmd tool to execute the file..
sqlcmd -S myServer\instanceName -i C:\myScript.sql
In case your have an unexplained "script error" for large sql files (> 100MB) which includes several INSERT, just replace "INSERT INTO" by "GO INSERT INTO" in your file, which will reduce size of transaction.