I4GL循環查詢

Question

我試圖解決這個問題最近幾天，但不知道該怎麼做。我正在嘗試從列的表中獲取3條記錄。如果有任何Informix 4GL大師出現，我需要一些幫助。

 declare s_curs cursor for 
      SELECT * FROM crcharge 
       WHERE chargenum IN 
       (SELECT shtwrd_no FROM crbookid WHERE crbookid.book_no = rpt.book_no) 

        let chgkey_count = 1 
      FOREACH s_curs into z_charge.* 
        let t_col = 15 
       if chgkey_count <= 3 then 
        let chgkey_count = chgkey_count + 1 
        let chgkey_count = t_chgkey 
        let scratch = z_charge.chgkey 
        let rpt.chgkey = scratch 
        call make_charge_section(scratch) returning rpt.chgkey 
        print 
        column 1, ESC, "&a15.5R",ESC,"&a12C", rpt.chgkey #t_col+2 , 

       end if 
      END FOREACH 

Answer 1

我覺得你的問題是，我已經在代碼的下面（輕度）修訂註釋掉行：

DECLARE s_curs CURSOR FOR 
    SELECT * FROM crcharge 
    WHERE chargenum IN 
      (SELECT shtwrd_no FROM crbookid WHERE crbookid.book_no = rpt.book_no) 

LET chgkey_count = 0 
FOREACH s_curs INTO z_charge.* 
    IF chgkey_count >= 3 THEN 
     EXIT FOREACH 
    END IF 
    LET chgkey_count = chgkey_count + 1 
    --LET chgkey_count = t_chgkey  -- Probable problem 
    LET scratch = z_charge.chgkey 
    LET rpt.chgkey = scratch 
    CALL make_charge_section(scratch) RETURNING rpt.chgkey 
    PRINT COLUMN 1, ESC, "&a15.5R",ESC,"&a12C", rpt.chgkey 
END FOREACH 

而且我想我會通過寫作更加簡化代碼：

LET chgkey_count = 0 
FOREACH s_curs INTO z_charge.* 
    IF chgkey_count >= 3 THEN 
     EXIT FOREACH 
    END IF 
    LET chgkey_count = chgkey_count + 1 
    LET rpt.chgkey = make_charge_section(z_charge.chgkey) 
    PRINT COLUMN 1, ESC, "&a15.5R",ESC,"&a12C", rpt.chgkey 
END FOREACH