Find the writing of a SQL statement.

shitgeb

Sorry, I would like to ask, can such a query be used on a database with a large amount of data? For example, if the query is performed on a data table with 5 million records, will it be very slow?

westevil

If there are other methods, this method can of course not be used. Of course, this method is a bit inefficient.

The problem is that I want to group the InQuantOrders and OutStockOrders statistics based on ModelsInfoNO and ShopWarehouseNO.

waxiaoning

The specified join must have a relationship and describe
FROM
(
SELECT DISTINCT ModelInfoNO FROM [InStockOrder Details]
union
SELECT DISTINCT ModelInfoNO FROM [OutStockOrder Details]
) A_x
INNER JOIN
(
SELECT DISTINCT InShopWarehouseNO AS ShopWarehouseNO FROM [InStockOrders]
union
SELECT DISTINCT OutShopWarehouseNO FROM [OutStockOrders]
)A_y
Is there a relationship description? ?

westevil

I just don't know how to connect the two sets behind FROM, and there is no relationship between the two sets after FROM. I just have to do the following queries based on these two sets.


Is there any other way to achieve my desired function?

waxiaoning

from a join c on a.column=c.column join b on b.column=c.column

westevil

no, sorry,

There are two behind my from

Such as
select ... from a,b
left join c on a.col = c.col and b.col = c.col2
left join d on a.col = d.col and b.col = d.col2

left join e on e.col = b.col
left join f on f.col = a.col

order by a.col

waxiaoning

What is the relationship between the two, united, or are they related to the latter?
What is your intention?
Fight 2V1 or 1V1V1

westevil

The two behind from have nothing to do with each other, they are relatively independent, but the left join on will use them for query conditions. You can look at all the codes above.

waxiaoning

from a join c on a.column=c.column join b on b.column=c.column

westevil

No, the eldest brother upstairs, I changed it as you did, but the data I found is wrong.

Don't you help me write it out completely.