I have Image
table with 3 columns: Id
, Name
, and RefId
- It will contain Id
from other table (with this example is Category
table and Product
table).
Category
table with 3 columns: Id
, Name
and ProductId
. Product
table includes 3 columns: Id
, Name
.
This is Product's data:
Id Name
659543D6-1A0D-4151-B94C-F44CCDA752B5 Product1
5C1A5A2F-4579-41D2-8FAE-93EF71451285 Product2
2C35A651-1681-4E5E-9F0C-315169BDFA1D Product3
And Category
's data:
Id Name ProductId
F3FFF612-1D6D-4447-B472-2486C4893CDD Category1 659543D6-1A0D-4151-B94C-F44CCDA752B5
4A2FF39D-13E0-4365-8DEA-7FAD6D6DF405 Category2 659543D6-1A0D-4151-B94C-F44CCDA752B5
599AEA59-8A85-409C-9026-7E4313AF523D Category3 659543D6-1A0D-4151-B94C-F44CCDA752B5
Image's data:
Id Name RefId
BDD396A2-37A7-4B20-B8C5-8EF2CD58D4C0 Image1 659543D6-1A0D-4151-B94C-F44CCDA752B5
7CDA01FF-B98A-4CDC-A92B-0E31A9CDCD20 Image2 F3FFF612-1D6D-4447-B472-2486C4893CDD
Please see this data for the example: Image1 is the image of the product and Image2 is the image of the category. And my query:
SELECT Category.Id, Category.Name, Product.Name, Image.Name
FROM Category
INNER JOIN Product
ON Category.ProductId = Product.Id
INNER JOIN Image
ON Category.Id = Image.RefId
-- ON Product.Id = Image.RefId
With this query only get Image2 or Image1. My problem is how to get 2 Image with only one query?
Are you looking for something like this?
SELECT c.Id category_id,
c.Name category_name,
p.Name product_name,
i1.Name category_image,
i2.Name product_image
FROM Category c JOIN Product p
ON c.ProductId = p.Id LEFT JOIN Image i1
ON c.Id = i1.RefId LEFT JOIN Image i2
ON p.Id = i2.RefId
Output:
| CATEGORY_ID | CATEGORY_NAME | PRODUCT_NAME | CATEGORY_IMAGE | PRODUCT_IMAGE | -------------------------------------------------------------------------------------------------------- | F3FFF612-1D6D-4447-B472-2486C4893CDD | Category1 | Product1 | Image2 | Image1 | | 4A2FF39D-13E0-4365-8DEA-7FAD6D6DF405 | Category2 | Product1 | (null) | Image1 | | 599AEA59-8A85-409C-9026-7E4313AF523D | Category3 | Product1 | (null) | Image1 |
Here is SQLFiddle demo