progress-4gl - SELECT IN 语句的 ABL 等价物是什么

Question

任何人请帮助我为 SELECT IN 声明等效的 ABL例如

SELECT column_name(s)
FROM table_name
WHERE column_name IN (value1,value2,...);

Answer 1

OR 显然是最简单的，但既然它已被宣布为 Not Acceptable ，也许这可以满足需要？

define variable i as integer no-undo.
define variable n as integer no-undo.
define variable cityList as character no-undo.

cityList = "boston,new york,chicago,...".

n = num-entries( cityList ).
do for i = 1 to n:
  for each customer no-lock where city = entry( i, cityList ):
    display customer.name customer.city.
  end.
end.

这将避免表扫描并且与 OR 一样高效，因为字段比较是相等匹配。