There are four types of Connection classes: SqlConnection, OleDbConnection, OdbcConnection and OracleConnection.
(1) The object connection of the Sqlconnection class is a SQL Server database;
(2) The object connection of the OracleConnection class is connected to the Oracle database;
(3) OleDbConneetion connection supports OLEDB databases, such as Access;
(4) The object connection of the OdbcConnection class supports ODBC databases.
All communication with the database is done through the Connection object.
To use OleDbConnection to read excel files in C#, you can follow the following steps: 1. Introduce System.Data.Ole