这段SQL语句的各个意思？

Question

问题遇到的现象和发生背景

问题相关代码，请勿粘贴截图

SELECT
tt.ItemCode AS ItemCode,
tt.ItemName AS ItemName,
tt.BatchNum AS BatchNum,
sum(tt.Quantity) AS Quantity,
tt.InvntryUom AS InvntryUom,
tt.WhsCode AS WhsCode,
tt. STATUS AS STATUS,
tt.StorageTime AS StorageTime
FROM
(
SELECT
T2.CODE AS ItemCode,
T2.NAME AS ItemName,
T1.LOT_INFO_LOT AS BatchNum,
T0.QTY_BASE_QTY AS Quantity,
T0.QTY_PACKAGE_NAME AS InvntryUom,
T1.LOT_INFO_ERP_CODE AS WhsCode,
T0.INV_TYPE AS STATUS,
now() AS StorageTime,
T0.ID
FROM
wms_inventory T0
LEFT JOIN wms_item_key T1 ON T0.SKU_ITEM_KEY_ID = T1.ID
LEFT JOIN wms_item T2 ON T2.ID = T1.ITEM_ID
LEFT JOIN wms_asn asn ON asn.CUSTOMER_BILL = T1.LOT_INFO_ASN_CUSTOMER_BILL
LEFT JOIN wms_bill_type billType ON asn.BILL_TYPE_ID = billType.ID
WHERE
QTY_BASE_QTY <> 0
AND T1.LOT_INFO_ERP_CODE IN (
101,
103,
104,
108,
201,
301,
302,
307,
412,
903
)
AND (
billType.ID IN (13, 14, 15, 16, 17)
OR (
billType.ID IN (12)
AND asn.BE_FEEDBACK = TRUE
)
OR billType.ID IS NULL
)
AND T2.LOT = 'Y'
AND T0.INV_TYPE = 'Normal'
GROUP BY
T2.CODE,
T2.NAME,
T1.LOT_INFO_LOT,
T0.QTY_BASE_QTY,
T0.QTY_PACKAGE_NAME,
T1.LOT_INFO_ERP_CODE,
T0.INV_TYPE,
T0.ID
ORDER BY
T2.CODE,
T1.LOT_INFO_LOT
) tt
GROUP BY
tt.ItemCode,
tt.BatchNum,
tt.WhsCode

运行结果及报错内容

我的解答思路和尝试过的方法

我想要达到的结果

语句中的各个意思

Answer 1

从代码中能看到的意思如下：
总共分为内外两个查询，
先看内部查询：从关联表中筛选过查询条件，筛选完之后根据分组字段分组，然后（排序字段1）排序，查询出字段（字段2），生成新的结果表。
外部结构的意思是：在结果表中再排序（排序字段2），查询出字段（字段1）最后展示结果。
注：其中的AS后表示起的别名，ON后面的条件是两表之间的关系条件，IN后是属性包含的值，AND的是关联词（并且），OR是关联词（或者），IS NULL是不为空。
具体干了啥内容，就要看你表存储的是什么？条件是什么情况下？业务是什么？这就没有办法帮你解析了。