How import excel file into mysql DB

If this is something you'll do only once, consider using EXCEL string functions to generate 'INSERT' statements.
Eg:

A                     | B                  | C                  | D
FOO                   | BAR                | BAZ                | 
12                    | 15                 | Beer               | "INSERT INTO MY_TABLE(FOO, BAR, BAZ) VALUES (" + A2 + ", " + B2 + ", '" + C2 + "');" 
999                   | 4                  | Winw               | "INSERT INTO MY_TABLE(FOO, BAR, BAZ) VALUES (" + A3 + ", " + B3 + ", '" + C3 + "');" 

If you need to programatically read an EXCEL file using C#, see this link. Then you can connect to MYSQL and generate insert commands from your C# code.

Hope this helps,
Pablo.