一条SQL语句

    SELECT distinct 
    [[shipment_requests.*]],
    [[shippingaddress.*]],
    [[billingaddress.*]],
    [[orders.*]],
    [[rep_infos.*]],
    [[warehouses.*]]
    FROM warehouses 
    INNER JOIN
    (select top {2} * 
     from shipment_requests 
     where warehouse_id={0} and shipment_requests.status_code='{1}') shipment_requests 
    　　ON warehouses.id = shipment_requests.warehouse_id 
    INNER JOIN shipment_request_line_items 
　　　　 ON shipment_requests.id = shipment_request_line_items.shipment_request_id 
　　 LEFT JOIN comments 
　　　　 ON shipment_requests.id=comments.shipment_request_id 
　　 LEFT JOIN orders 
        ON shipment_requests.order_id = orders.id 
    LEFT JOIN order_line_items 
        ON orders.id=order_line_items.order_id  
    INNER JOIN rep_infos 
        ON shipment_requests.rep_info_id=rep_infos.id 
    INNER JOIN addresses shippingaddress 
        ON shipment_requests.shipping_address_id = shippingaddress.id 
    INNER JOIN addresses billingaddress 
        ON shipment_requests.billing_address_id = billingaddress.id

首先遇到的问题是[[shipment_requests.*]],两个中括号是什么意思。单步跟到程序里发现被替换成了{shipment_requests.*}。这{}又不能直接在SQLSERVER里面运行。后问了老人才知道，这{}是hibernate框架自己定义的一个与类关联的东西。

然后就是不明白连续的连接是怎么运行的。

比如:

select ... from A

LEFT JOIN B ON A.id = B.id

LEFT JOIN C ON B.id = C.id。

困惑的是，C表究竟是和Ａ表做了左连接；还是Ｃ表和Ｂ表做了左连接。

思考之后发现，这两个猜想得出的结果是一样。所以，这个过程可以理解成这样，就是进行了 select ... from A LEFT JOIN B ON A.id = B.id 得出的结果集，再和C表做了左连接。