Datatable转为Sql语句，这里是转为Mysql，如果需要转为其他Sql，小小的修改即可

 public static string DataTableToSQL(DataTable dataTable, DataTableToSQLType tpye, string SQLWhere = null)
        {
            if (dataTable.TableName == "" || dataTable.TableName == null)
            {
                return "";
            }

            StringBuilder sb = new StringBuilder();
            int i = 0;
            int j = 0;
            if (tpye == DataTableToSQLType.INSERT)
            {
                for (i = 0; i < dataTable.Rows.Count; i++)
                {
                    sb.AppendFormat("INSERT INTO {0}(", dataTable.TableName);

                    //拼前半段INSERT
                    for (j = 0; j < dataTable.Columns.Count; j++)
                    {
                        if (j == dataTable.Columns.Count - 1)
                        {
                            sb.AppendFormat("{0})", dataTable.Columns[j].Caption);
                        }
                        else
                        {
                            sb.AppendFormat("{0},", dataTable.Columns[j].Caption);
                        }
                    }
                    //拼后半段VALUES
                    sb.Append(" VALUES(");
                    for (j = 0; j < dataTable.Columns.Count; j++)
                    {
                        var value = GetValue(dataTable.Columns[j].DataType, dataTable.Rows[i][j]);
                        if (j == dataTable.Columns.Count - 1)
                        {
                            if (string.IsNullOrEmpty(value + ""))
                                sb.AppendFormat("{0});", "NULL");
                            else
                                sb.AppendFormat("{0});", value);
                        }
                        else
                        {
                            if (string.IsNullOrEmpty(value + ""))
                                sb.AppendFormat("{0},", "NULL");
                            else
                                sb.AppendFormat("'{0}',", value);
                        }
                    }
                    sb.AppendLine();
                }
            }
            else if (tpye == DataTableToSQLType.UPDATE)
            {
                for (i = 0; i < dataTable.Rows.Count; i++)
                {
                    //判断行是否被修改,修改才生成sql
                    //if (dataTable.Rows[i].RowState == DataRowState.Modified)
                    //{
                    sb.AppendFormat("UPDATE {0} SET ", dataTable.TableName);
                    for (j = 0; j < dataTable.Columns.Count; j++)
                    {
                        var value = GetValue(dataTable.Columns[j].DataType, dataTable.Rows[i][j]);
                        if (dataTable.Columns[j].ColumnName == "update_time" && dataTable.Rows[i][j] != null)
                        {
                            value = Convert.ToDateTime(dataTable.Rows[i][j]).ToString("yyyy-MM-dd HH:mm:ss");
                        }
                        if (j == dataTable.Columns.Count - 1)
                        {
                            if (string.IsNullOrEmpty(value + ""))
                                sb.AppendFormat(" {0}={1}", dataTable.Columns[j].Caption, "NULL");
                            else
                                sb.AppendFormat(" {0}='{1}'", dataTable.Columns[j].Caption, value + "");
                        }
                        else
                        {
                            if (string.IsNullOrEmpty(value + ""))
                                sb.AppendFormat(" {0}={1},", dataTable.Columns[j].Caption, "NULL");
                            else
                                sb.AppendFormat(" {0}='{1}',", dataTable.Columns[j].Caption, value + "");
                        }
                    }
                    if (!string.IsNullOrEmpty(SQLWhere))
                        sb.AppendFormat(" WHERE ", SQLWhere);
                    else
                        sb.AppendFormat(" WHERE id='{0}';", dataTable.Rows[i]["id"]);
                    sb.AppendLine();
                }
                //}
            }
            else if (tpye == DataTableToSQLType.DELETE)
            {
                //判断用户是否录入自定义条件
                if (!string.IsNullOrEmpty(SQLWhere))
                    sb.AppendFormat("DELETE {0} WHERE {1} ", dataTable.TableName, SQLWhere);
                else
                {
                    sb.AppendFormat("DELETE {0} WHERE {1} IN (", dataTable.TableName, dataTable.Columns[0].Caption);
                    for (i = 0; i < dataTable.Rows.Count; i++)
                    {

                        if (i < dataTable.Rows.Count - 1)
                        {
                            sb.AppendFormat("'{0}',", dataTable.Rows[i][0]);
                        }
                        else
                        {
                            sb.AppendFormat("'{0}');", dataTable.Rows[i][0]);
                        }
                    }
                }

            }
            return sb.ToString();
        }

　　判断时间类型

 private static object GetValue(Type type, object value)
        {
            if (type == typeof(DateTime))
            {
                if (value != null&&value!=System.DBNull.Value)
                {
                    return Convert.ToDateTime(value).ToString("yyyy-MM-dd HH:mm:ss");
                }
            }
            return value;
        }

　　Sql操作模式

 public enum DataTableToSQLType
        {
            INSERT,
            UPDATE,
            DELETE
        }