[英]Nested mysql while loop not returning expected results
I have 2 tables, and I'm trying to use a nested while loop to list all possibilities. 我有2个表,并且尝试使用嵌套的while循环列出所有可能性。 Unfortunately, I'm only getting a small subset of results. 不幸的是,我只得到一小部分结果。 Any help is much appreciated. 任何帮助深表感谢。
Products Table 产品表
Product_ID | Product_Name | Product_Desc
0 | Box | Big Box
1 | Toy | Nice Toy
City Table 城市表
City_ID | City_Name
0 | Cincinnati
1 | Detroit
2 | San Francisco
3 | San Diego
4 | New York
Expected desired results: 预期的预期结果:
0 Box Big Box 0 Cincinnati
0 Box Big Box 1 Detroit
0 Box Big Box 2 San Francisco
0 Box Big Box 3 San Deigo
0 Box Big Box 4 New York
1 Toy Nice Toy 0 Cincinnati
1 Toy Nice Toy 1 Detroit
1 Toy Nice Toy 2 San Francisco
1 Toy Nice Toy 3 San Diego
1 Toy Nice Toy 4 New York
My Incorrect Results: 我不正确的结果:
0 Box Big Box 0 Cincinnati
1 Toy Nice Toy 0 Cincinnati
Here is my code: 这是我的代码:
query = "SELECT * FROM Products";
$result = mysqli_query($con, $query);
$query2 = "SELECT * FROM Cities";
$result2 = mysqli_query($con, $query2);
while($row = mysqli_fetch_assoc($result))
{
$product_id = $row['Product_ID'];
$product_name = $row['Product_Name'];
$product_desc = $row['Product_Desc'];
while($row = mysqli_fetch_assoc($result2))
{
$city_id = $row['City_ID'];
$city_name = $row['City_Name'];
}
echo "$product_id $product_name $product_desc $city_id $city_name\n";
}
Unfortunately, the above is not working and I'm only getting this result. 不幸的是,上述方法不起作用,我只能得到这个结果。 Should I be using a foreach product instead? 我应该改用foreach产品吗?
实际上,您可以使用单个查询获得相同的结果,而无需使用嵌套循环
$query = "SELECT p.*,c.* FROM Products p,City c";
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