如何在 Oracle 存储过程中获取逗号分隔值

Question

我必须将FlightDate、FlightNumbers 作为参数传递给 Oracle 存储过程，如下所示。

CREATE OR REPLACE PROCEDURE GetPaxDetails(
   FlyingDate IN PAX_DETAILS.FlightDate%TYPE, 
   FlightNumbers IN VARCHAR(300))
IS
BEGIN
    -- Assume that we've received **FlightNumbers** as '0620,0712,0154'
    -- Basically I am trying to select all passenger details (PAX_DETAILS) 
    -- for those flights passed in as a parameter(**FlightNumbers**) 
    -- for the specified dates
    -- In this procedure the query should be generated something like below:
    SELECT * 
      FROM PAX_DETAILS 
     WHERE TO_DATE(FlightDate,'DDMONYY') BETWEEN TO_DATE(FlyingDate,'DDMONYY') 
                                             AND TO_DATE(FlyingDate,'DDMONYY') + 1 
       AND FlightNo IN ('0620,0712,0154')

END

我不明白如何在查询中将 FlightNumbers 参数转换为 AND FlightNo IN ('0620,0712,0154') 之类的参数。

Answer 1

作为方法之一，regexp_substr() 和 regexp_count() 正则表达式函数可用于将源字符串拆分为表行，然后您可以轻松地将结果包含在您的 IN 子句中：

-- splitting a comma separated string
select regexp_substr(FlightNumbers, '[^,]+', 1, level) as num
  from dual
connect by level <= regexp_count(FlightNumbers, '[^,]+')

因此，例如，如果您将FlightNumbers 传递为“0620,0712,0154”，则上述查询将产生以下结果：

NUM
--------
0620
0712
0154

有了这些，您的最终查询将是：

with numbers(num) as(
   select regexp_substr(FlightNumbers, '[^,]+', 1, level) as num
     from dual
  connect by level <= regexp_count(FlightNumbers , '[^,]+')
 )
SELECT *           -- do not forget INTO clause
  FROM PAX_DETAILS 
 WHERE TO_DATE(FlightDate,'DDMONYY') BETWEEN TO_DATE(FlyingDate,'DDMONYY') 
                                         AND TO_DATE(FlyingDate,'DDMONYY') + 1 
   AND FlightNo IN (select num
                      from numbers);