sql multiple rows of data into the data row

Target: sql multiple rows of data into the data row

Involving grammar: decode, nvl, left join, subquery.

 　　　　--nvl (a, b) -> does not exist if a display b, or display a 
　　　　 --decode, Oracle unique if, else; eg: decode ( a, 1,2); if a = 1, it Back to 2 
2      the SELECT
 . 3          A.EMPLOYEE_GID, . 4          A.EVALUATE_YEAR, . 5          the DECODE (of the NVL (A.EVALUATION_STEP, 0), 0, 0,. 1,. 1) the AS STEP1,
 . 6          the DECODE (of the NVL (B.EVALUATION_STEP, 0), 0 , 0, 2,. 1) the AS STEP2,
 . 7          the DECODE (of the NVL (C.EVALUATION_STEP, 0), 0, 0,. 3,. 1) the AS STEP3,
 . 8          (of the NVL (C.EVALUATION_STEP, B.EVALUATION_STEP)
 . 9            || the DECODE ( of the NVL (A.EVALUATION_STEP, 0), 0, 0,. 1,. 1 )
 10            || the DECODE (of the NVL (B.EVALUATION_STEP, 0), 0, 0, 2,. 1)) COMBINE_STEP the AS,
 . 11         DECODE((NVL(C.EVALUATION_STEP, B.EVALUATION_STEP)
12                 || DECODE(NVL(A.EVALUATION_STEP, 0), 0, 0, 1, 1)
13                 || DECODE(NVL(B.EVALUATION_STEP, 0), 0, 0, 2, 1)), 311, 2, 301, 2, 300, 0, 310, 1, 211, 2, 201, 2) AS WITHDRAW_STEP14                 ,
15         DECODE((NVL(C.EVALUATION_STEP, B.EVALUATION_STEP)
16                 || DECODE(NVL(A.EVALUATION_STEP, 0), 0, 0, 1, 1)
17                 || DECODE(NVL(B.EVALUATION_STEP, 0), 0, 0, 2, 1)), 311, 1, 301, 0, 300, 0, 310, 0, 211, 1, 201, 0) AS WITHDRAW_COLOR18     FROM
19         (
20             SELECT
21                 *
22             FROM
23                 T_EVALUATION A
24             WHERE
25                 EVALUATION_STEP = 1
26         ) A
27         LEFT JOIN (
28             SELECT
29                 *
30             FROM
31                 T_EVALUATION A
32             WHERE
33                 EVALUATION_STEP = 2
34         ) B ON A.EVALUATE_YEAR = B.EVALUATE_YEAR
35                AND A.EMPLOYEE_GID = B.EMPLOYEE_GID
36         LEFT JOIN (
37             SELECT
38                 *
39             FROM
40                 T_EVALUATION A
41             WHERE
42                 EVALUATION_STEP = 3
43         ) C ON A.EVALUATE_YEAR = C.EVALUATE_YEAR
44                AND A.EMPLOYEE_GID = C.EMPLOYEE_GID
45     WHERE
46         A.EVALUATE_YEAR = (
47             SELECT
48                 VALUE
49             FROM
50                 S_SYSTEM_CONFIG
51             WHERE
52                 KEY = 'CURRENT_FINANCE_YEAR'
53                 AND ENABLE = 1
54         )
55         AND ( C.EVALUATION_STEP IS NOT NULL
56               OR B.EVALUATION_STEP IS NOT NULL )