Question

我刚写完第一个PLSQL函数。这就是它的作用。

SQL函数尝试将重复的时间戳重置为NULL。

从表call_records中找到所有重复的时间戳。（使用分组依据）
循环遍历每个时间戳。查找具有相同时间戳的所有记录（时间为1，因此在给定时间内仅存在1条记录）
从步骤2中找到的所有记录中将时间戳更新为NULL

这里是SQL函数的样子。

CREATE OR REPLACE FUNCTION nullify() RETURNS INTEGER AS $$
DECLARE
T call_records.timestamp%TYPE;
-- Not sure why row_type does not work
-- R call_records%ROWTYPE;
S integer;
CRNS bigint[];
TMPS bigint[];
sql_stmt varchar = '';
BEGIN
FOR T,S IN (select timestamp,count(timestamp) as times from call_records where timestamp IS NOT NULL group by timestamp having count(timestamp) > 1)
LOOP
  sql_stmt := format('SELECT ARRAY(select plain_crn from call_records where timestamp=%s limit %s)',T,S-1);
  EXECUTE sql_stmt INTO TMPS;
  CRNS := array_cat(CRNS,TMPS);
END LOOP;

  sql_stmt = format('update call_records set timestamp=null where plain_crn in (%s)',array_to_string(CRNS,','));
  RAISE NOTICE '%',sql_stmt;
  EXECUTE sql_stmt ;
  RETURN 1;
END
$$ LANGUAGE plpgsql;

帮助我了解更多PL / pgSQL语言，我建议如何更好地完成它。

@a_horse_with_no_name：这是DB结构的样子 \ d + call_records;

id  integer primary key
plain_crn  bigint
timestamp  bigint
efd        integer default 0




    id    |    efd     | plain_crn  | timestamp 
----------+------------+------------+-----------
    1     | 2016062936 | 8777444059 | 14688250050095        
    2     | 2016062940 | 8777444080 | 14688250050095
    3     | 2016063012 | 8880000000 | 14688250050020      
    4     | 2016043011 | 8000000000 | 14688240012012
    5     | 2016013011 | 8000000001 | 14688250050020 
    6     | 2016022011 | 8440000001 |

现在，

select timestamp,count(timestamp) as times from call_records where timestamp IS NOT NULL group by timestamp having count(timestamp) > 1 

  timestamp      |    count 
-----------------+-----------
 14688250050095  |      2
 14688250050020  |      2

我想要的只是将重复的时间戳更新为null，以便只有其中一个记录具有给定的时间戳。

简而言之，上面的查询应该像这样返回结果

   select timestamp,count(timestamp) as times from call_records where timestamp IS NOT NULL group by timestamp;

      timestamp      |    count 
    -----------------+-----------
     14688250050095  |      1
     14688250050020  |      1

Answer 1

您可以直接使用数组变量（使用谓词<?xml version="1.0" encoding="UTF-8"?> <api context="/omdbapi" name="omdbapi" xmlns="http://ws.apache.org/ns/synapse"> <resource methods="GET" uri-template="/*"> <inSequence> <send> <endpoint> <address trace="disable" uri="http://www.omdbapi.com/"/> </endpoint> </send> </inSequence> <outSequence> <datamapper config="gov:datamapper/omdbapiConfig.dmc" inputSchema="gov:datamapper/omdbapiConfig_inputSchema.json" inputType="XML" outputSchema="gov:datamapper/omdbapiConfig_outputSchema.json" outputType="XML"/> <respond/> </outSequence> <faultSequence/> </resource> </api>进行过滤 - 使用动态SQL是错误的：

postgres=# DO $$
DECLARE x int[] = '{1,2,3}'; 
result int[];
BEGIN
  SELECT array_agg(v) 
    FROM generate_series(1,10) g(v) 
   WHERE v = ANY(x)
    INTO result;
  RAISE NOTICE 'result is: %', result;
END;
$$;
NOTICE:  result is: {1,2,3}
DO

接下来 - 这是典型的无效功能 - 它不会返回任何有趣的内容。通常这些函数在一切正常或引发异常时都不返回任何内容。返回1 =ANY()是没用的。

RETURN 1

改进PL / pgSQL函数

1 个答案: