SqlCommand,OracleCommand,OleDbCommand 或 OdbcCommand比较

4种连接方式异同比较

SqlCommand.Parameters中的参数变量要在前面加“@”

如:myCommand.CommandText = "SELECT CustomerID, CompanyName FROM Customers WHERE Country = @Country AND City = @City";OracleCommand.Parameters中的參數變量要在前面加“：”如:myCommand.CommandText = "UPDATE test SET test1 =:test1, test2 =:test2 WHERE id = :id";OleDbCommand 或 OdbcCommand 为“？”
如:myCommand.CommandText = "SELECT CustomerID, CompanyName FROM Customers WHERE Country = ? AND City = ?";

所以，需要注意：

OracleCommand oCmd = new OracleCommand();

oCmd.CommandText = "SELECT * FROM table WHERE Col = :Col ORDER BY Col2";

oCmd.Parameters.Add("Col",col);

而连接SQLServer：

SqlCommand sqlCmd = new SqlCommand();

sqlCmd .CommandText = "SELECT * FROM table WHERE Col = @Col ORDER BY Col2";

sqlCmd .Parameters.Add("@Col",col);