我是公司IT部门的新开发人员。我觉得完全失去了很多在我们的代码中编写的sql。有许多查询长达数百行。这是＆＃34;较小＆＃34;的一个例子。一个（表/字段名称已被修改，但结构相同）。我只是吮吸这个还是真的很难理解？您如何重写它以使其更易于管理/可理解？
SELECT pd.commission_header_id COMMISSION_HEADER_ID
,pd.sales_rep_id DIRECT_SALESREP_ID
,pd.org_id ORG_ID
,LEAST(100, innview.spilt_percent) SPLIT_PCT
,pd.source SOURCE
,pd.application APPLICATION
,pd.plan PLANE
,pd.pay_freq pay_freq
,pd.emp_app_count EMP_APP_COUNT
,pd.client_name CLIENT_NAME
,pd.fed_id FED_ID
,pd.off_nbr OFF_NBR
,pd.payroll_num payroll_num
,TO_DATE(pd.product_start_date,'DD-MON-YY') PRODUCT_START_DATE
,pd.loss_date LOSS_DATE
,pd.acquisitions_ind ACQUISITIONS_IND
,pd.source_of_business SOURCE_OF_BUSINESS
,pd.prev_br_clt_nbr PREV_BR_CLT_NBR
,pd.previous_method PREVIOUS_METHOD
,pd.natl_acct_number NATL_ACCT_NUMBER
,pd.product_name PRODUCT_NAME
,pd.lost_reason LOST_REASON
,pd.client_id CLIENT_ID
,pd.lead_nbr LEAD_NBR
,pd.processed_date PROCESSED_DATE
,pd.rep_type REP_TYPE
,pd.order_number ORDER_NUMBER
,pd.conversion_type CONVERSION_TYPE
,SUBSTR(original_billing_info,1,INSTR(original_billing_info,'|',1,1)-1) BILLING_APPLICATION
,SUBSTR(original_billing_info,INSTR(original_billing_info,'|',1,1)+1,INSTR(original_billing_info,'|',1,2)-INSTR(original_billing_info,'|',1,1)-1) BILLING_CODE
,SUBSTR(original_billing_info,INSTR(original_billing_info,'|',1,2)+1,INSTR(original_billing_info,'|',1,3)-INSTR(original_billing_info,'|',1,2)-1) BILLING_PROD_GRP_NM
,SUBSTR(original_billing_info,INSTR(original_billing_info,'|',1,3)+1) BILLING_FIELD_FOR_CHRGS
,SUBSTR(original_discount_info,1,INSTR(original_discount_info,'|',1,1)-1) DISCOUNT_APPLICATION
,SUBSTR(original_discount_info,INSTR(original_discount_info,'|',1,1)+1,INSTR(original_discount_info,'|',1,2)-INSTR(original_discount_info,'|',1,1)-1) DISCOUNT_CODE
,CASE WHEN (NVL(innview.trans,0)) = 0
THEN 0
ELSE ( NVL(innview.comm,0)) / ( NVL(innview.trans,0))
END ORIGINAL_COMM_PCT
,pd.record_type RECORD_TYPE
,innview.trans PAR_SUM
,NVL(ocp.oic_clients_pk, pxmis.oic_client_products_pk_seq.nextval) CLIENT_PRODUCT_ID
,pd.associated_with ASSOCIATED_WITH_ID
,pd.refferal_sale refferal_sale
,pd.parent_client_nbr PARENT_CLIENT_NBR
FROM pxmis.pd_commissions pd
JOIN pxmis.oic_lookback_months olm ON (pd.application = olm.application
AND pd.plan = olm.plan)
LEFT OUTER JOIN pxmis.oic_client_products ocp ON (pd.off_nbr = ocp.off_nbr
AND pd.payroll_num = ocp.payroll_num
AND pd.application = ocp.application
AND pd.plan = ocp.plan
AND pd.sales_rep_id = ocp.direct_salesrep_id
AND pd.source = ocp.source
AND ocp.record_type in (:1,:2)
AND NVL(pd.refferal_sale,'NON REF') = NVL(ocp.refferal_sale,'NON REF'))
JOIN (SELECT SUM(NVL(transaction_amount,0)) as trans
,SUM(commission_amount) as comm
,SUM(pd2.oic_split_percent) as spilt_percent
,pd2.application as application
,pd2.plan as code
,pd2.sales_rep_id as sales_rep_id
,pd2.payroll_num as client_nbr
,LPAD(pd2.off_nbr,4,0) as off_nbr
FROM pxmis.pd_commissions pd2
JOIN pxmis.oic_lookback_months olm2 ON (pd2.application = olm2.application
AND pd2.plan = olm2.plan)
WHERE CASE WHEN (pd2.record_type IN ('SAPBA','ASAPBA'))
THEN pd2.SUB_RECORD_TYPE
ELSE 'Eligible'
END = 'Eligible'
AND pd2.record_type IN ('SDBDA', 'ASDBDA',
decode(:3,'CHCST','SAPBA',NULL),
decode(:4,'CHCST','ASAPBA',NULL),
'SAPBP','ASAPBP')
AND pd2.processed_date BETWEEN ADD_MONTHS(:5,(olm2.lookback_months_high - 1) * -1) AND ADD_MONTHS(:6, (olm2.lookback_months_low - 2) * -1) - 1
and :7 between olm2.effective_start_date and olm2.effective_end_date
and olm2.function_type = :8
GROUP BY pd2.application
,pd2.plan
,pd2.sales_rep_id
,pd2.payroll_num
,LPAD(pd2.off_nbr,4,0)) innview on (innview.application = pd.application
AND innview.code = pd.plan
AND innview.sales_rep_id = pd.sales_rep_id
AND innview.client_nbr = pd.payroll_num
AND innview.off_nbr = LPAD(pd.off_nbr,4,0))
WHERE :9 BETWEEN olm.effective_start_date AND olm.effective_end_date
AND pd.sales_rep_id <> -3
AND pd.record_type IN ('SAPBP','ASAPBP')
AND NOT EXISTS(SELECT 'X'
FROM pxmis.pd_commissions pd3
WHERE pd3.application = pd.application
AND pd3.plan = pd.plan
AND pd3.sales_rep_id = pd.sales_rep_id
AND pd3.payroll_num = pd.payroll_num
AND (pd3.record_type in ('CHCST','ACHCST')
or ( pd3.record_type = 'SAPBA'
and pd3.sub_record_type = 'Chargeback')))
AND pd.commission_header_id = (SELECT MAX(pd4.commission_header_id)
FROM pxmis.pd_commissions pd4
WHERE pd4.application = pd.application
AND pd4.plan = pd.plan
AND pd4.sales_rep_id = pd.sales_rep_id
AND pd4.payroll_num = pd.payroll_num
AND pd4.record_type = pd.record_type)
AND olm.function_type = :10
AND pd.processed_date BETWEEN ADD_MONTHS(:11,(olm.lookback_months_high - 1) * -1) AND ADD_MONTHS(:12, (olm.lookback_months_low - 2) * -1) - 1
AND pd.source = :13
AND pay_freq IS NOT NULL
AND pd.core_conversion_revenue IS NULL;
答案 0 :(得分：0)
旁注:(由于我的声誉，我无法发表评论：）
这是我第一次回答。希望它会有所帮助。 我不知道它是否有帮助，但大多数SQL脚本（可能全部）都可以用其他语言重写。例如，您可以在C＃.NET LINQ中使用 JOINS 。
但我通常将SQL脚本分开的方法是查找关键字并查看它们的作用。不要混淆小字母的大字母。
SELECT 功能选择所有数据。
TO_DATE 函数表示它会将字符串转换为日期（来源：http://www.techonthenet.com/oracle/functions/to_date.php）
LEAST 函数返回您作为参数的变量之间的最小数字（来源：http://www.techonthenet.com/oracle/functions/least.php）
您可以为每个功能执行此操作，并尝试掌握脚本的功能。
我认为你可以在这里结束脚本：FROM pxmis.pd_commissions pd
我也看到你做了 JOIN 。 在这里，您可以正确地创建一个新脚本并运行该代码。
现在我可能无法使其更具可读性。 （主要是因为我使用.NET C＃linqs。）
希望它在某种程度上有所帮助。