Postgresql：EXECUTE sql_cmd 与 CREATE TEMP TABLE temp_tbl 合并 AS SELECT

Question

Soo，事情是这样的，我在我的数据库方法中使用了 2 种方法：

1.) 是从各种字符串中组合和SQL查询，这取决于我需要过滤掉的内容：

sql_cmd := 'SELECT count(*) FROM art_short_term_finished WHERE (entry_time <= ''' || timestamp_up || ''' AND exit_time >= ''' || timestamp_down || ''') AND ' ||  time_filter || ' AND entry_zone = ' || zone_parameter || ' AND park_uuid = ' || park_id_p || '';
EXECUTE sql_cmd INTO shortterm_counter;

2.) 将大 table 的一部分复制到较小的临时 table 中并使用它：

    -- Get the data from FPL into smaller table for processing
    DROP TABLE IF EXISTS temp_fpl_filtered;
    CREATE TEMP TABLE temp_fpl_filtered AS SELECT car_id FROM flexcore_passing_log fpl WHERE fpl.zone_leaved = '0' AND fpl.status IN (SELECT status_id FROM fpl_ok_statuses) AND fpl.park_uuid = park_id_p AND (fpl.datetime BETWEEN row_i.start_d AND row_i.end_d);

但是如果我想混合这两者呢？

我想让 CREATE TEMP TABLE temp_fpl_filtered AS 之后的 SELECT 根据存储过程的输入参数有不同的 WHERE 子句，而不必在一个存储过程中编写相同的语句 xy 次程序。

但我的做法是：

-- art class is shortterm, check shortterm history
IF art_class_p = 1 OR article_p = 0 THEN
  -- create temporary table derivated from shortterm history
  IF article_p = 0 THEN
    article_p_filter := '';
  ELSE
    article_p_filter := ' AND article_id = ' || article_p;
  END IF;

  short_cmd := 'SELECT car_id, article_id, entry_time, exit_time FROM art_short_term_finished WHERE zone_leaved = ''0'' AND status IN (SELECT status_id FROM fpl_ok_statuses) ''' || article_p_filter || ''' AND park_uuid = ''' || park_id_p || ''' AND (entry_time <= ''' || timestamp_up || ''' AND exit_time >= ''' || timestamp_down || ''')'; 

  DROP TABLE IF EXISTS temp_short_full;
  CREATE TEMP TABLE temp_short_full AS short_cmd;
  --EXECUTE sql_cmd INTO shortterm_counter;
END IF;

当我尝试插入存储过程时抛出异常：

psql:report_parking_average.sql:107: ERROR:  syntax error at or near "short_cmd"
LINE 50:       CREATE TEMP TABLE temp_fpl_filtered AS short_cmd;
                                                      ^

另外，再试一次：

EXECUTE short_cmd INTO TEMP TABLE temp_short_full;

不工作..

Answer 1

您需要将 CREATE TABLE 部分包含到您生成的 SQL 中：

short_cmd := 'CREATE TEMP TABLE temp_short_full AS SELECT car_id, article_id, entry_time, exit_time FROM art_short_term_finished WHERE zone_leaved = ''0'' AND status IN (SELECT status_id FROM fpl_ok_statuses) ''' || article_p_filter || ''' AND park_uuid = ''' || park_id_p || ''' AND (entry_time <= ''' || timestamp_up || ''' AND exit_time >= ''' || timestamp_down || ''')'; 

DROP TABLE IF EXISTS temp_short_full;
execute short_cmd;

Postgresql：EXECUTE sql_cmd 与 CREATE TEMP TABLE temp_tbl 合并 AS SELECT

Postgresql: EXECUTE sql_cmd merge with CREATE TEMP TABLE temp_tbl AS SELECT

postgresql

dynamic-sql

plpgsql