Question

我有以下查询，其中我正在创建一个临时表来从不同的表中提取和插入数据，并在循环中选择记录。

DO $$
DECLARE
    --Only transactions found between the given start date and end date for the given events will be considered
  START_TIME_STR     VARCHAR := '2018-01-28 00:00:00';
  END_TIME_STR       VARCHAR := '2018-02-27 23:59:59';
  v_category         INTEGER := 2; 

BEGIN


  CREATE TEMPORARY TABLE cntr_track_detail (
    cntr_no      VARCHAR(11) NOT NULL,
    cntr_trxn_id BIGSERIAL   NOT NULL,
    surajbari    TEXT default null,
    mokha        TEXT default null,
    gate_in      TEXT default null,
    port_in      TEXT default null,
    terminal_in  TEXT default null,
    terminal_name VARCHAR(100) default null
  ) ON COMMIT DROP;


  CREATE TEMPORARY TABLE tranx1 ON COMMIT DROP AS select b.* from 
  (SELECT ctm.cntr_no,ctm.cntr_trxn_id FROM cntr_trxn_mapping ctm INNER JOIN cntr_track_time_log cttl 
    ON cttl.cntr_trxn_id = ctm.cntr_trxn_id AND ctm.cntr_cycle_id = v_category
    AND cttl.timestamp_gnrl >= start_time AND cttl.timestamp_gnrl <= end_time AND cttl.event_id in (13,21,1,19))b;

    raise notice 'size of tranx1 is,%', (select count(t.*) from tranx1 t);


  FOR v_intrim_loop IN (select distinct(t.*) from tranx1 t)
  LOOP
    BEGIN

      INSERT INTO cntr_track_detail (cntr_no, cntr_trxn_id, surajbari, mokha, gate_in, port_in, terminal_in, terminal_name) VALUES (v_intrim_loop.cntr_no, v_intrim_loop.cntr_trxn_id,
      (SELECT x from something LIMIT 1),

      (SELECT x from something LIMIT 1),


      (SELECT x from something LIMIT 1),


      (SELECT x from something LIMIT 1),


      (SELECT x from something LIMIT 1),

       (SELECT x from something LIMIT 1)
 );
 raise notice 'iteration ,%',iter;
 iter := iter +1;
    END;
  END LOOP;

END $$;
SELECT a.* FROM cntr_track_detail a ORDER BY a.cntr_no;

我想问一下，如果子查询什么都不返回，那么插入这种方式是否会导致迭代失败。感谢。

Answer 1

当您使用OrgRelations删除重复值时，可能您的表中包含重复值，因此会删除这些值，这就是为什么您的行数减少的原因。

如果子查询不返回任何内容，则可以将子查询中的值插入表中

1 个答案: