C#连接数据库的方法

cmd.CommandText = cmdText; cmd.Parameters.AddRange(parameters);

return cmd.ExecuteNonQuery();//返回执行了多少行 }

} public static object ExecuteScalar(SqlConnection conn, string cmdText,

params SqlParameter[] parameters) {

using (SqlCommand cmd = conn.CreateCommand()) {

cmd.CommandText = cmdText; cmd.Parameters.AddRange(parameters);

return cmd.ExecuteScalar(); }

} public static DataTable ExecuteDataTable(SqlConnection conn, string cmdText,

params SqlParameter[] parameters) {

using (SqlCommand cmd = conn.CreateCommand()) {

cmd.CommandText = cmdText; cmd.Parameters.AddRange(parameters);

using (SqlDataAdapter adapter = new SqlDataAdapter(cmd)) {

DataTable dt = new DataTable(); adapter.Fill(dt);

return dt; }

} }

public static object ToDBValue(this object value) {

return value == null ? DBNull.Value : value; }