具有联接但列有效的无效标识符

Question

我正在尝试在Oracle SQL Developer中将Customer_ID上具有Order_Header的客户加入，并且即使两个表在两个表中都存在列的情况下也遇到“无效标识符”错误。

Select C.customer_name, Order_Header.total_sales, order_detail.quantity, 
C.customer_ID
From Customers C
Join Order_Header Using (Customer_ID);

Answer 1

您可以运行以下内容吗？

Select C.* From Customers C

和

Select O.* From Order_Header O

我想您可能缺少架构名称select t.* from schema.table。

Answer 2

阅读上面的评论，您一直在说

  

“订单详细信息”部分要进行第三次连接，但是即使删除了该部分，也存在相同的错误。

什么是“那部分”？如果您的意思是与ORDER_DETAILS表进行联接，则应添加而不是删除“部分”。或者，您应删除ORDER_DETAILS子句中不存在的属于FROM表的列。

如果提供表的描述，将会有所帮助；我使用最小列集自己创建了它们，以便查询正常工作。看看。

SQL> -- CUSTOMERS: column names taken from your query
SQL> create table customers
  2    (customer_id   number constraint pk_cust primary key,
  3     customer_name varchar2(20));

Table created.

SQL> -- ORDER_HEADER: ORDER_ID must exist in order to join it with ORDER_DETAIL
SQL> create table order_header
  2    (order_id      number constraint pk_oh primary key,
  3     customer_id   number constraint fk_oh_cust references customers (customer_id),
  4     total_sales   number);

Table created.

SQL> -- ORDER_DETAIL: I added ORDER_ID as a reference to ORDER_HEADER
SQL> create table order_detail
  2    (order_id      number constraint fk_od_oh references order_header (order_id),
  3     quantity      number);

Table created.

使用所有3个表的 full 查询将如下所示：

SQL> select c.customer_name,
  2         oh.total_sales,
  3         od.quantity,
  4         c.customer_id
  5  from customers c join order_header oh on oh.customer_id = c.customer_id
  6                   join order_detail od on od.order_id = oh.order_id;

no rows selected

---

截至您的查询：

SQL> -- query you wrote, slightly formatted:
SQL> Select C.customer_name,
  2         Order_Header.total_sales,
  3         order_detail.quantity,
  4         C.customer_ID
  5  From Customers C
  6  Join Order_Header Using (Customer_ID);
       C.customer_ID
       *
ERROR at line 4:
ORA-25154: column part of USING clause cannot have qualifier

这意味着您应该删除第4行中的“ C.”：

SQL> Select C.customer_name,
  2         Order_Header.total_sales,
  3         order_detail.quantity,
  4         customer_ID
  5  From Customers C
  6  Join Order_Header Using (Customer_ID);
       order_detail.quantity,
       *
ERROR at line 3:
ORA-00904: "ORDER_DETAIL"."QUANTITY": invalid identifier

现在，您遇到另一个错误-您正在引用QUANTITY子句中从未引用过的ORDER_DETAIL列；因此-从FROM中删除该列：

SELECT

或者，在SQL> Select C.customer_name, 2 Order_Header.total_sales, 3 -- order_detail.quantity, 4 customer_ID 5 From Customers C 6 Join Order_Header Using (Customer_ID); no rows selected 子句中添加ORDER_DETAIL，这将使您返回到我最初发布的查询。