sql - 一起使用 SQL 和 Perl - 哪些应该用于通用功能？

Question

我没有发现这个问题的任何欺骗，但如果有一个或多个，我很抱歉 - 请用链接发表评论。

这个问题很基本，答案可能也是如此。如果我使用 Perl 来执行和操作数据库，当涉及共享函数时，我应该将负担放在哪个途径(Perl 与 SQL)上？

功能如 - LEN , IF/ELSE , CONCAT以及更多以及算术函数，例如，这两个系统都是通用的。

这个 SQL 语句加载了 case 块和其他可以用 Perl 复制的操作。那么，如果相同的逻辑可以在 Perl 中实现，是否值得重写？哪些条件会影响决定将一个系统的负担放在另一个系统上？

SELECT DISTINCT     s.id stu_id,
                    stu_id.fullname stu_name,
                    p.major1 major,
                    p.minor1 minor,
                    s.reg_hrs,
                    NVL(st.cum_earn_hrs,0) ttl_hrs,
                    p.adv_id curr_adv_id,
                    adv_id.fullname curr_adv_name,
                    CASE    WHEN    (p.adv_id <> 35808 AND p.major1 = 'NS')                 THEN    (1165)
                            WHEN    (p.adv_id = 35808 AND p.major1 = 'NS')                  THEN    (35808)
                            WHEN    (p.adv_id = 9179 AND p.major1 = 'DART')                 THEN    (9179)
                            WHEN    (p.minor1 IN ('RT','RESP') AND st.cum_earn_hrs >= 24)   THEN    (70897)
                            WHEN    (p.major1 IN ('CDSC','CDSD'))                           THEN    (52125)
                            WHEN    (p.major1 IN ('CA','CB'))                               THEN    (24702)
                            WHEN    (p.minor1 = 'NURS')                                     THEN    (51569)
                            WHEN    (p.major1 = 'LEG')                                      THEN    (13324)
                            WHEN    (p.major1 = 'CC')                                       THEN    (73837)
                            WHEN    (p.major1 = 'CCRE')                                     THEN    (1133)
                            WHEN    ((p.adv_id IN (SELECT DISTINCT id FROM fac_rec WHERE stat = 'I'))
                                    OR (st.cum_earn_hrs < 24 AND (p.adv_id||p.major1) IN (SELECT DISTINCT (id||major) FROM adv_detail WHERE stat = 'A' AND max_stu > 0 AND min_hrs >= 24))
                                    OR (s.id NOT IN (SELECT DISTINCT stu.id FROM stu_acad_rec stu, sess_info si WHERE stu.yr = si.prev_yr AND stu.sess = si.prev_sess AND stu.reg_hrs > 0 AND stu.reg_stat IN ('C','R') AND stu.prog = 'UNDG'))
                                    OR ((p.adv_id||p.major1) IN (SELECT DISTINCT (id||major) FROM adv_detail WHERE stat <> 'A' OR max_stu <= 0))
                                    OR ((p.adv_id||p.major1) NOT IN (SELECT DISTINCT (id||major) FROM adv_detail WHERE stat = 'A' AND max_stu > 0)))
                            THEN    (9238)
                            ELSE    (p.adv_id)
                    END     new_adv_id,
                    CASE    WHEN    (p.adv_id <> 35808 AND p.major1 = 'NS')                 THEN    ('Deborah')
                            WHEN    (p.adv_id = 35808 AND p.major1 = 'NS')                  THEN    ('Veronica')
                            WHEN    (p.adv_id = 9179 AND p.major1 = 'DART')                 THEN    ('Stella')
                            WHEN    (p.minor1 IN ('RT','RESP') AND st.cum_earn_hrs >= 24)   THEN    ('Lisa')
                            WHEN    (p.major1 IN ('CDSC','CDSD'))                           THEN    ('Joanne')
                            WHEN    (p.major1 IN ('CA','CB'))                               THEN    ('Barbara')
                            WHEN    (p.minor1 = 'NURS')                                     THEN    ('Karen')
                            WHEN    (p.major1 = 'LEG')                                      THEN    ('Nancy')
                            WHEN    (p.major1 = 'CC')                                       THEN    ('Alberta')
                            WHEN    (p.major1 = 'CCRE')                                     THEN    ('Naomi')
                            WHEN    ((p.adv_id IN (SELECT DISTINCT id FROM fac_rec WHERE stat = 'I'))
                                    OR (st.cum_earn_hrs < 24 AND (p.adv_id||p.major1) IN (SELECT DISTINCT (id||major) FROM adv_detail WHERE stat = 'A' AND max_stu > 0 AND min_hrs >= 24))
                                    OR (s.id NOT IN (SELECT DISTINCT stu.id FROM stu_acad_rec stu, sess_info si WHERE stu.yr = si.prev_yr AND stu.sess = si.prev_sess AND stu.reg_hrs > 0 AND stu.reg_stat IN ('C','R') AND stu.prog = 'UNDG'))
                                    OR ((p.adv_id||p.major1) IN (SELECT DISTINCT (id||major) FROM adv_detail WHERE stat <> 'A' OR max_stu <= 0))
                                    OR ((p.adv_id||p.major1) NOT IN (SELECT DISTINCT (id||major) FROM adv_detail WHERE stat = 'A' AND max_stu > 0)))
                            THEN    ('Staff')
                            ELSE    (adv_id.fullname)
                    END     new_adv_name,
                    CASE    WHEN    (p.adv_id <> 35808 AND p.major1 = 'NS')                 THEN    ('NS majors not assigned to Veronica go to Debbie')
                            WHEN    (p.adv_id = 35808 AND p.major1 = 'NS')                  THEN    ('NS majors stay with Veronica')
                            WHEN    (p.adv_id = 9179 AND p.major1 = 'DART')                 THEN    ('DART majors stay with Stella')
                            WHEN    (p.minor1 IN ('RT','RESP') AND st.cum_earn_hrs >= 24)   THEN    ('RT-RESP minors go to Lisa')
                            WHEN    (p.major1 IN ('CDSC','CDSD'))                           THEN    ('CDSC-CDSD majors go to Joanne')
                            WHEN    (p.major1 IN ('CA','CB'))                               THEN    ('CA-CB majors go to Barbara')
                            WHEN    (p.minor1 = 'NURS')                                     THEN    ('NURS minors go to Karen')
                            WHEN    (p.major1 = 'LEG')                                      THEN    ('LEG majors go to Nancy')
                            WHEN    (p.major1 = 'CC')                                       THEN    ('CC majors go to Alberta')
                            WHEN    (p.major1 = 'CCRE')                                     THEN    ('CCRE majors go to Naomi')
                            WHEN    (p.adv_id IN (SELECT DISTINCT id FROM fac_rec WHERE stat = 'I'))
                            THEN    ('Current advisor is inactive')
                            WHEN    (st.cum_earn_hrs < 24 AND (p.adv_id||p.major1) IN (SELECT DISTINCT (id||major) FROM adv_detail WHERE stat = 'A' AND max_stu > 0 AND min_hrs >= 24))
                            THEN    ('Total credits for this student did not meet the advisor reqs for this major')
                            WHEN    (s.id NOT IN (SELECT DISTINCT stu.id FROM stu_acad_rec stu, sess_info si WHERE stu.yr = si.prev_yr AND stu.sess = si.prev_sess AND stu.reg_hrs > 0 AND stu.reg_stat IN ('C','R') AND stu.prog = 'UNDG'))
                            THEN    ('This student did not attend '||si.prev_sess||si.prev_yr)
                            WHEN    ((p.adv_id||p.major1) IN (SELECT DISTINCT (id||major) FROM adv_detail WHERE (stat <> 'A' OR max_stu <= 0)))
                            THEN    ('Current advisor is not advising students with this major')
                            WHEN    ((p.adv_id||p.major1) NOT IN (SELECT DISTINCT (id||major) FROM adv_detail WHERE stat = 'A' AND max_stu > 0))
                            THEN    ('Current advisor is not advising students with this major')
                            ELSE    ('Student will stay with current advisor')
                    END     change_comm
FROM                stu_acad_rec s,
                    prog_enr_rec p,
                    OUTER stu_stat_rec st,
                    id_rec stu_id,
                    id_rec adv_id,
                    sess_info si
WHERE               s.id = p.id
                    AND s.id = st.id
                    AND s.id = stu_id.id
                    AND p.adv_id = adv_id.id
                    AND s.yr = si.curr_yr
                    AND s.sess = si.curr_sess
                    AND s.reg_hrs > 0
                    AND s.reg_stat IN ('C','R')
                    AND s.prog = 'UNDG'
                    AND p.prog = 'UNDG'
                    AND st.prog = 'UNDG'
                    AND s.id NOT IN (3,287,9238,59999) {System test use IDs}
INTO TEMP           stu_list
WITH NO LOG;

Answer 1

我会从性能的角度和重用的角度来看待这个问题。

如果你在两边都试一试，你可能会发现一个比另一个快得多——这将是一个很好的指标。

如果您将在多个地方重复使用某个查询，那么您可能希望将大部分业务逻辑合并到查询中，因此您不需要在 GUI 中复制这些逻辑。

(我不得不说，虽然严格来说不是你问题的一部分，但大部分案例逻辑看起来你可以在模式中建立一个很好的模型，并用正常连接替换案例到一些关联表)