進展4GL查詢可選

Question

「的突破」我有一個查詢：

for each a where ..., 
    each b where ..., 
    each c where ..., 
     break by c.xxx by c.yyy by c.zzz. 

我需要的休息根據用戶輸入改變。

當我嘗試定義查詢：

def query qa for a, b, c. 
if ... then open qa for each a... (as above) 

那麼它將不能編譯，因爲：

BREAK requires query be defined SCROLLING. (14283) 

我怎樣才能「用破」設定的變量？

Answer 1

查找「query-prepare」。這就是讓您完全自定義查詢的神奇功能。

我今天早晨要編寫這樣的查詢：

/* dyn.p 
*/ 

define variable tbl as character no-undo. 
define variable brk as character no-undo. 

define variable b as handle no-undo. 
define variable q as handle no-undo. 

tbl = "customer". 
brk = "state". 

create query q. 
create buffer b for table tbl. 

q:set-buffers(b). 

q:query-prepare("for each " + tbl + " break by " + brk). 
q:query-open. 
q:get-next(). 

do while q:query-off-end = false: 

    if q:first-of(1) then clear all. 

    display 
    b:buffer-field('CustNum'):buffer-value() 
    b:buffer-field('Name' ):buffer-value() 
    b:buffer-field('State' ):buffer-value() 
    with 
    down 
    . 

    down 1. 

    q:get-next(). 


end. 

return. 

運行上面的代碼，反對「sports2000」。