Question

我有一个具有以下结构的表：

#include <stdio.h>
#include <stdlib.h>

typedef struct celltag{
    char name[11];
    double time;
    struct celltag *next;
} celltype;

int compare (const void *ap, const void *bp)
{
    celltype *a = *((celltype * const *)ap);
    celltype *b = *((celltype * const *)bp);

    return (a->time > b->time) - (a->time < b->time);
}

int main (void) {

    celltype    c1 = { .name = "three", .time = 127.21 },
                c2 = { .name = "one", .time = 127.1 },
                c3 = { .name = "two", .time = 127.19 },
            *pc[] = { &c1, &c2, &c3 };
    size_t n = sizeof pc / sizeof *pc;

    qsort (pc, n, sizeof *pc, compare);

    for (size_t i = 0; i < n; i++)
        printf ("%-5s  %6.2f\n", pc[i]->name, pc[i]->time);
}

我需要将这些值转换为以下格式：

$ ./bin/qsort_ptp_struct
one    127.10
two    127.19
three  127.21

Answer 1

您无需使用 PIVOT ，您可以使用一个简单的查询即可。

SELECT t1.refno, 
       t1.code AS Code1, 
       t2.code AS Code2, 
       t1.trantype, 
       t1.amount 
FROM   @table t1 
       INNER JOIN @table t2 
               ON t1.refno = t2.refno                      
                  AND T1.code < T2.code

Online Demo

Answer 2

您可以尝试以下查询。

;WITH Tab (RefNo,Code,TranType,Remarks,Amount,rowno) 
AS
(SELECT  T.RefNo 
         , T.Code
         ,TranType
         ,Remarks
         ,Amount
         , RN = ROW_NUMBER() OVER (PARTITION BY T.RefNo ORDER BY  T.Code )
   FROM   Table1 T)

   SELECT RefNo,Code1 = MAX( CASE WHEN N.rowno=1 THEN N.Code ELSE 0 END ),
   Code2 = MAX( CASE WHEN N.rowno=2 THEN N.Code ELSE 0 END ) ,
   TranType,Remarks,Amount FROM Tab n
   GROUP BY N.RefNo,TranType,Remarks,Amount

使用Pivot或Unpivot将值分配到特定列

2 个答案: