SQL查詢，用於將當前行值與先前的行值合並

Question

我有以下格式的源數據。

RN  ID  NAME
1   1   P
2   2   Q
3   3   R
4   4   S
5   5   T
6   1   A
7   2   B
8   3   C
9   4   D
10  5   E

我需要以下輸出。

RN  ID  NAME
1   1   P
2   2   PQ
3   3   PQR
4   4   PQRS
5   5   PQRST
6   1   A
7   2   AB
8   3   ABC
9   4   ABCD
10  5   ABCDE

請為此提供SQL查詢。

Answer 1

SQL小提琴

Oracle 11g R2架構設置 ：

CREATE TABLE table_name ( RN, ID, NAME ) As
SELECT  1, 1,   'P' FROM DUAL UNION ALL
SELECT  2, 2,   'Q' FROM DUAL UNION ALL
SELECT  3, 3,   'R' FROM DUAL UNION ALL
SELECT  4, 4,   'S' FROM DUAL UNION ALL
SELECT  5, 5,   'T' FROM DUAL UNION ALL
SELECT  6, 1,   'A' FROM DUAL UNION ALL
SELECT  7, 2,   'B' FROM DUAL UNION ALL
SELECT  8, 3,   'C' FROM DUAL UNION ALL
SELECT  9, 4,   'D' FROM DUAL UNION ALL
SELECT 10, 5,   'E' FROM DUAL

查詢1 ：

SELECT RN,
       ID,
       REPLACE( SYS_CONNECT_BY_PATH( NAME, ',' ), ',' ) AS NAME
FROM   TABLE_NAME
START WITH ID = 1
CONNECT BY PRIOR ID + 1 = ID
AND        PRIOR ASCII(NAME) + 1 = ASCII(NAME)

結果 ：

| RN | ID |  NAME |
|----|----|-------|
|  1 |  1 |     P |
|  2 |  2 |    PQ |
|  3 |  3 |   PQR |
|  4 |  4 |  PQRS |
|  5 |  5 | PQRST |
|  6 |  1 |     A |
|  7 |  2 |    AB |
|  8 |  3 |   ABC |
|  9 |  4 |  ABCD |
| 10 |  5 | ABCDE |

查詢2 ：

SELECT RN,
       ID,
       REPLACE( SYS_CONNECT_BY_PATH( NAME, ',' ), ',' ) AS NAME
FROM   TABLE_NAME
START WITH ID = 1
CONNECT BY PRIOR ID + 1 = ID
AND        PRIOR RN + 1 = RN

結果 ：

| RN | ID |  NAME |
|----|----|-------|
|  1 |  1 |     P |
|  2 |  2 |    PQ |
|  3 |  3 |   PQR |
|  4 |  4 |  PQRS |
|  5 |  5 | PQRST |
|  6 |  1 |     A |
|  7 |  2 |    AB |
|  8 |  3 |   ABC |
|  9 |  4 |  ABCD |
| 10 |  5 | ABCDE |