One of the oracle notes implements the statistics of multiple fields (multiple counts) in a table

One of the oracle notes implements the statistics of multiple fields (multiple counts) in a table the Requirements: Count the total number of work orders, the total number of unprocessed work orders, the total number of completed work orders, and the total number of unfinished work orders in the WAIT_ORDER table. the Table structure: For the convenience of examples, the WAIT_ORDER table has only two fields, namely ID and STATUS, where STATUS is the status of the work order. 1 means unprocessed, 2 means completed, 3 means total outstanding. the SQL: [sql] SELECT     COUNT(B.ID) AS The total number of work orders, COUNT(CASE           WHEN B.status IN ('1') THEN           'un_deal'   www.2cto.com           END) Total Open Work Orders,           COUNT(CASE         WHEN B.status IN ('2') THEN                                                     END) total number of completed work orders,   COUNT(CASE WHEN B.status = '3' THEN                          …