当不同表中的两列具有相同名称时，如何使用SqlDataReader读取数据？

I have two columns named 'Name' in two different tables. One is in the Store table the other is in the Product table. How do I differentiate which one is read?

我在两个不同的表中有两个名为“Name”的列。一个在Store表中,另一个在Product表中。如何区分读取哪一个?

The data is taken from 4 different tables using left joins as shown in the query below.

使用左连接从4个不同的表中获取数据,如下面的查询所示。

var conn = new SqlConnection("serverinfo");
SqlCommand query = new SqlCommand("SELECT Store.StoreID, Store.Name, 
Product.Name, " +
" StockRequest.Quantity, StoreInventory.StockLevel from Store" +
" LEFT JOIN StoreInventory ON StoreInventory.StoreID = Store.StoreID" 
+ " LEFT JOIN Product ON StoreInventory.ProductID = 
Product.ProductID" + " LEFT JOIN StockRequest ON StockRequest.StoreID 
= Store.StoreID", conn);

SqlDataReader read;

        try {
            conn.Open();
            read = query.ExecuteReader();
            while (read.Read()) {
                Console.WriteLine("{0} {1} {2} {3} {4}",
                                  read["StoreID"],
                                  read["Name"],
                                  read["Name"],
                                  read["Quantity"],
                                  read["StockLevel"]);

            }
            conn.Close();
            } catch (Exception e) {}

The table names are Store, Product, StockRequest, StoreInventory.

表名是Store,Product,StockRequest,StoreInventory。

Right now the data for both of the 'Name' columns are taken from the Store table. I am unable to take the 'Name' data from the Product table.

现在,两个“名称”列的数据都来自Store表。我无法从Product表中获取'Name'数据。

1 个解决方案

#1

You could use alias to give a different name to the duplicate column.

您可以使用别名为重复列指定不同的名称。

SqlCommand query = new SqlCommand("SELECT Store.StoreID, 
"Store.Name as StoreName," + 
"Product.Name as ProductName," +
" StockRequest.Quantity, StoreInventory.StockLevel from Store" +
" LEFT JOIN StoreInventory ON StoreInventory.StoreID = Store.StoreID" 
+ " LEFT JOIN Product ON StoreInventory.ProductID = 
Product.ProductID" + " LEFT JOIN StockRequest ON StockRequest.StoreID 
= Store.StoreID", conn);

Then just use the right name when reading it, like:

然后在阅读时使用正确的名称,例如:

read["StoreID"],
read["StoreName"], read["ProductName"],
read["Quantity"], read["StockLevel"]

#1