数据库中批量插入数据的方法

If using SQL Server, 

SqlBulkCopy.WriteToServer(DataTable)

SqlBulkCopy.WriteToServer Method (DataTable)
Or also with SQL Server, you can write it to a .csv and use 

BULK INSERT

BULK INSERT (Transact-SQL)
If using MySQL, you could write it to a .csv and use 

LOAD DATA INFILE

LOAD DATA INFILE Syntax
If using Oracle, you can use the array binding feature of ODP.NET

Bulk Insert to Oracle using .NET
If SQLite:

How do I bulk insert with SQLite?
Faster bulk inserts in sqlite3?