This is my database
Product
+----+----------+
| Id | Name |
+----+----------+
| 1 | Product1 |
| 2 | Product2 |
| 3 | Product3 |
+----+----------+
Category
+----+-----------+
| Id | Name |
+----+-----------+
| 1 | Category1 |
| 2 | Category2 |
| 3 | Category3 |
+----+-----------+
ProductCategory
+----+------------+------------+
| Id | ProductId | CategoryId |
+----+------------+------------+
| 1 | 1 | 1 |
| 2 | 1 | 1 |
| 3 | 2 | 2 |
+----+------------+------------+
Now, I want to get all products with its categories. In my repository I added this code:
public async Task<IEnumerable<Product>> GetAllProducts()
{
var products = await _dbConnection.QueryAsync<Product, Category, Product>(
#"
SELECT p.Id, p.Name, c.Id, c.Name
FROM Product p
LEFT JOIN ProductCategory pc on pc.ProductId = p.Id
LEFT JOIN Category c on c.Id = pc.CategoryId
",
(product, category) =>
{
product.Categories.Add(category);
return product;
}, splitOn: "Id",
transaction: _dbTransaction
);
return products.GroupBy(p => p.Id).Select(g =>
{
var product = g.First();
product.Categories = g.Select(p => p.Categories.Single()).ToList();
return product;
});
}
In results, I got list of 3 items:
Product1 with 2 categories (Category1, Category2)
Product2 with 1 category (Category2)
Product3 with 1 category (null)
The problem is that I don't want Product3 to have filled category list with null value. What I wanted is to have empty Category list in this case. What should I do to achieve that?
Why not just change the mapping function to?:
(product, category) =>
{
if (category!=null)
{
product.Categories.Add(category);
}
return product;
}
That will of course fail for the .Single() in GroupBy, but how would you group by missing category anyway?
It's easier to return the raw data from the query first and then do some processing. Then you have all logic in one place. For example:
var products = await _dbConnection
.QueryAsync<Product, Category, (Product Product, Category Category)>(
#"
SELECT p.Id, p.Name, c.Id, c.Name
FROM Product p
LEFT JOIN ProductCategory pc on pc.ProductId = p.Id
LEFT JOIN Category c on c.Id = pc.CategoryId
"
,(product, category) => (product, category)
, splitOn: "Id"
,transaction: _dbTransaction
);
return products.GroupBy(pc => pc.Product.Id)
.Select(g =>
{
var product = g.First().Product;
product.Categories = g.Select(pc => pc.Category)
.Where(c => c != null).ToList();
return product;
});
The null check skips the null category that's inevitably in the SQL result set because of the outer joins.
Related
I have 3 tables:
Recipe
RecipeIngredient (fk RecipeId)
RecipeTag (fk RecipeId)
Recipe
+-----+------------+-------------+------+
| Id | Name | Ingredients | Tags |
+-----+------------+-------------+------+
| 99 | Mango Sago | | |
| 100 | Tuna Melt | | |
+-----+------------+-------------+------+
RecipeIngredient
+-----+----------+------------+---------------------------------------------+----------+
| Id | Quantity | UOM | Name | RecipeId |
+-----+----------+------------+---------------------------------------------+----------+
| 115 | 2 | Pieces | Whole Ripe Mangoes | 99 |
| 116 | 1 | Pieces | Jolly Coconut Milk, 400ml | 99 |
| 117 | 2 | Tablespoon | Sugar | 99 |
| 118 | 1 | Cup | Cooked Tapioca Pearls | 99 |
| 119 | NULL | NULL | Mango Cubes | 99 |
| 120 | 1 | Pieces | Doña Elena 100% Tuna Shredded 185g, drained | 100 |
| 121 | 2 | Tablespoon | White Onion, chopped | 100 |
| 122 | 2 | Tablespoon | Jolly Real Mayonnaise | 100 |
| 123 | 1 | Tablespoon | Celery or Pickle Relish, finely chopped | 100 |
| 124 | 8 | Pieces | White Bread | 100 |
| 125 | 4 | Pieces | Cheddar or Mozzarella Cheese | 100 |
+-----+----------+------------+---------------------------------------------+----------+
RecipeTag
+----+-----------------+----------+
| Id | Name | RecipeId |
+----+-----------------+----------+
| 72 | Filipino Desert | 99 |
| 73 | Quick Recipe | 99 |
| 74 | Quick Recipe | 100 |
+----+-----------------+----------+
How do I add all the RecipeIngredient to the Ingredients column in the Recipe table and add all the RecipeTag to the Tags column in the Recipe table in the controller?
public JsonResult GetAllRecipes()
{
var recipes = db.Recipes.OrderBy(a => a.Name).ToList();
return new JsonResult { Data = recipes, JsonRequestBehavior = JsonRequestBehavior.AllowGet };
}
public JsonResult GetAllRecipes()
{
var recipes = (from rec db.Recipes
join ing in db.Ingredients on rec.Id equals ing.RecipeId into subIngrs
from subIngr in subIngrs.DefaultIfEmpty()
join tag in db.RecipeTags on rec.Id equals tag.RecipeId into subTags
from subTag in subTags.DefaultIfEmpty()
order by rec.Name
select new
{
rec.Id,
rec.Name,
Quantity = subIngr == null ? null : subIngr.Quantity,
IngrName = subIngr == null ? null : subIngr.Name,
UOM = subIngr == null ? null : subIngr.UOM,
TagName = subTag == null ? null : subTag.Name
}).ToList()
.GroupBy(x => new { x.Id, x.Name }).Select(x => new
{
x.Key.Id,
x.Key.Name,
Ingredients = string.Join("," x.Where(y => y.IngrName != null).Select(y => $"{y.Quantity} {y.UOM} {y.Name}").Distinct()),
Tags = string.Join("," x.Where(y => y.TagName != null).Select(y => y.TagName).Distinct())
}).ToList();
return new JsonResult { Data = recipes, JsonRequestBehavior = JsonRequestBehavior.AllowGet };
}
You can use STUFF if you want to do it in sql.
SELECT a.Id,
Recipe = a.Name,
Ingredient = STUFF((
SELECT ','
+ CAST(b.Quantity AS NVARCHAR(10)) + ' '
+ b.UOM + ' '
+ b.Name
FROM dbo.RecipeIngredient b
WHERE a.Id = b.RecipeId
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 1, ''),
Tag = STUFF((
SELECT ',' + c.Name
FROM dbo.RecipeTag c
WHERE a.ID = c.RecipeId
FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 1, '')
FROM Recipe a
Here's a Demo.
To execute the stored procedure and return the results as a json in your controller method
var recipies = db.Database.SqlQuery<RecipeVM>("NameOfStoredProcedure");
return Json(recipes, JsonRequestBehavior = JsonRequestBehavior.AllowGet);
where RecipeVM is
public class RecipeVM
{
public int Id { get; set; }
public string Name { get; set; }
public string Ingredient { get; set; }
public string Tag { get; set; }
}
Assuming you have set up your navigation properties correctly (i.e. Recipe contains public virtual ICollection<RecipieIngredient> Ingredients { get; set; } etc) then to get the data in the concatenated format you want,
public JsonResult GetAllRecipes()
{
var recipes = db.Recipes
.OrderBy(r => r.Name)
.ToList() // this is necessary because we need Linq to Objects for the string formatting
.Select(r => new // can be anonymous objects because we are returning a JsonResult
{
Id = r.Id,
Name = r.Name,
Ingredients = r.Ingredients
.Select(i => string.Format("{0} {1} {2}", i.Quantity, i.UOM, i.Name).TrimStart())
.Aggregate((c, n) => c + ", " + n),
Tags = r.Tags
.Select(t => t.Name)
.Aggregate((c, n) => c + ", " + n)
});
return Json(recipes, JsonRequestBehavior = JsonRequestBehavior.AllowGet);
}
Side note, your RecipeIngredient table indicates nullable values for Quantity and UOM hence the TrimStart. I am assuming that if either Quantity or UOM is null, then the other is also null
Alternatively, (in LINQ to SQL) you can use
var recipes = (from r in db.Recipies
join i in db.RecipeIngredient on r.Id equals i.RecipeId into Ingedients
join t in db.RecipeTag on r.Id equals t.RecipeId into Tags
orderby r.Name
select new
{
Name = r.Name,
Ingedients = Ingedients,
Tags = Tags
}).ToList()
.Select(x => new
{
Name = x.Name,
Ingredients = x.Ingedients
.Select(y => string.Format("{0} {1} {2}", y.Quantity, y.UOM, y.Name).Trim())
.Aggregate((c, n) => c + ", " + n),
Tags = x.Tags
.Select(y => y.Name)
.Aggregate((c, n) => c + ", " + n)
});
return Json(recipes, JsonRequestBehavior = JsonRequestBehavior.AllowGet);
I'm not exactly sure what you're trying to accomplish, but if you're trying to programatically insert this data from user input, you could just iterate over the ingredients/tags and build a string to insert into the relevant tables.
If you're trying to do this from existing data, then I'm not sure EF is the tool to use. I would just write SQL scripts to handle that.
I have a table that I need to summarize in a report. This is my sample table.
Orders
_____________________________________
CustomerId | CustomerName | OrderType
___________|______________|__________
1 | Adam | Shoe
1 | Adam | Shoe
1 | Adam | Shoe
1 | Adam | Hat
1 | Adam | Hat
2 | Bill | Shoe
2 | Bill | Hat
3 | Carl | Sock
3 | Carl | Hat
I am trying to summarize this to pass back in my viewmodel without a loop. This is the result that I am attempting to achieve.
CustomerName | Shoe | Hat | Sock | Total Orders
------------ | ---- | --- | ---- | ------------
Adam | 3 | 2 | 0 | 5
Bill | 1 | 1 | 0 | 2
Carl | 0 | 1 | 1 | 2
//var resultList = dbContext.Orders.OrderBy(o => o.CustomerId);
How can I use GroupBy and Count to achieve my desired results? Would that be the best approach to take?
group clause (C# Reference)
var summary = from order in dbContext.Orders
group order by order.CustomerId into g
select new {
CustomerName = g.First().CustomerName ,
Shoe = g.Count(s => s.OrderType == "Shoe"),
Hat = g.Count(s => s.OrderType == "Hat"),
Sock = g.Count(s => s.OrderType == "Sock"),
TotalOrders = g.Count()
};
if items are fixed:
public List<OrderViewModel> GetCustOrders()
{
var query = orders
.GroupBy(c => c.CustomerName)
.Select(o => new OrderViewModel{
CustomerName = o.Key,
Shoe = o.Where(c => c.OrderType == "Shoe").Count(c => c.CustomerId),
Hat = o.Where(c => c.OrderType == "Hat").Count(c => c.CustomerId),
Sock = o.Where(c => c.OrderType == "Sock").Count(c => c.CustomerId),
Total = o.Count(c => c.CustomerId)
});
return query;
}
use SQL is one option, i tested it and get exactly what you want:
select p.*, t.total as 'Total Orders' from
(
select CustomerName, count(CustomerId) total from Orders group by CustomerName
) as t inner join
(
select * from Orders
pivot(count(CustomerId)
for OrderType in ([Shoe], [Hat], [Sock])
) as piv
)as p on p.CustomerName = t.CustomerName
i want to join different column where the output would be this using linq
| Name | Address | Cellphone | Email |
| John | NY | n/a | johndoe#y.c |
| John | NY | 123456781 | n/a |
And i want my output to be one liner combined
| Name | Address | Cellphone | Email |
| John | NY | 123456781 | johndoe#y.c |
I Tried it on SQL server and this is the Query that answers the needed output
select a.ID, a.Name , a.Address ,(
SELECT wc1.[Values]
FROM Contact as wc1 where wc1.infoID = a.ID and wc1.ContactTypeID = 56) as Email
,(
SELECT wc1.[Values]
FROM Contact as wc1 where wc1.infoID = a.ID and wc1.ContactTypeID = 59) as Cellphone
from Info as a where a.ID = 100
Also tried it on Linq but it produces different row with same ID
var an = (from a in db.Info
join b in db.Contact on a.ID equals b.InfoID
where b.ContactTypeID == 56
|| b.ContactTypeID == 59
select new
{
a.ID,
a.LastName,
a.FirstName,
a.MiddleName,
b.ContactTypeID,
b.Values
}).ToList();
List<InfoList> wlist = new List<InfoList>();
foreach (var row in an)
{
InfoList ci = new InfoList
{
ID = row.ID,
Name = row.FirstName + " " + row.MiddleName + " " + row.LastName,
ContactType = GetLookupDisplayValById(row.ContactTypeID),
ContactValue = row.Values
};
wlist.Add(ci);
}
return Json(wlist.ToList(), JsonRequestBehavior.AllowGet);
Can someone help me translate this to a Linq Statement
Your SQL does not use JOIN, so why are you trying to introduce it in LINQ?
var an = (from a in db.Info
select new
{
a.ID,
a.LastName,
a.FirstName,
a.MiddleName,
Email = db.Contact.FirstOrDefault(b => b.InfoID == a.ID && b.ContactTypeIF == 56).Values,
Cellphone = db.Contact.FirstOrDefault(b => b.InfoID == a.ID && b.ContactTypeIF == 59).Values,
}).FirstOrDefault(x => x.ID == 100);
You can use the Pivot table the mentioned link shows how to use it: http://www.codeproject.com/Tips/500811/Simple-Way-To-Use-Pivot-In-SQL-Query
I have a property database and I am trying to get all properties added by an user. The main table is called 'Property' and there are other tables which are 'PropertyPhotos', 'City' etc. A sample database is as follows:
'Property' table
PropertyId| Area| State| UserId | ...
1 | 1 | 1 | AAA | ...
2 | 2 | 3 | BBB | ...
3 | 1 | 1 | AAA | ...
'PropertyPhotos'
PropertyPhotoId| PropertyId| FileName | MainPic
1 | 1 | x1.jpg | 1
2 | 1 | X2.jpg | 0
3 | 2 | x3.jpg | 1
4 | 3 | x4.jpg | 1
5 | 3 | x5.jpg | 0
6 | 3 | x6.jpg | 0
'AreaLookUp'
AreaLookUpId | AreaDescription
1 | London
2 | Birmingham
3 | Manchester
I am trying to write a LINQ query to get information on property added by a particular user. But I am stuck when trying to retrieve the 'FileName' of the MainPic and also get count. See code below with comments.
So, for the data above, this query should return the following for "UserId = AAA"
PropertyId | ... | MainPicSrc | PhotoCount
1 | ... | x1.jpg | 2
3 | ... | xr4jpg | 3
Please help!
public IEnumerable<PropertyExcerptViewModel> GetAddedPropertyVmByUserId(string userId)
{
var addedProperties = from p in db.Property where p.UserId == userId
join pp in db.PropertyPhotos on p.PropertyId equals pp.PropertyId
join a in db.AreaLookUp on p.Area equals a.AreaLookUpId
select new PropertyExcerptViewModel
{
PropertyId = p.PropertyId,
PropertyType = p.PropertyType,
TransactionType = p.TransactionType,
IsPropertyDisabled = p.IsPropertyDisabled,
IsPropertyVerified = p.IsPropertyVerified,
IsPropertyNotified = p.IsPropertyNotified,
MainPicSrc = pp.FileName, // How to put where condition to only get FileName of just the Main Pic
PhotoCount = pp.Count(), // How to get count of all pics with a particular proprtyId
Price = p.Price,
NoOfBedrooms = p.NoOfBedrooms,
Area = a.AreaLookUpDescription,
ShortDescription = (p.Description.Length > 300) ? p.Description.Substring(0,300) : p.Description
};
return addedProperties.ToList();
}
I think where statement might be easier if you care about clear match
var data=(from c in db.Property from v in db.PropertyPhotos from
n in db.AreaLookUpId
where c.PropertyId==v.PropertyId && c.Area==n.AreaLookUpId && c.UserId=="AAA"
// the rest is your select
PhotoCount = v.Where(j=>j. PropertyId==c.PropertyId).Count()
This also works - I ended up doing it this way
var addedProperties = from p in db.Property
join ppic in db.PropertyPhotos on p.PropertyId equals ppic.PropertyId into pp
join a in db.AreaLookUp on p.Area equals a.AreaLookUpId
join cal in db.CalendarEvent on p.PropertyId equals cal.PropertyId into c
where p.UserId == userId
select new PropertyExcerptViewModel
{
PropertyId = p.PropertyId,
PropertyType = p.PropertyType,
PropertyCategoryDescription = pc.PropertyCategoryDescription,
TransactionType = p.TransactionType,
IsPropertyDisabled = p.IsPropertyDisabled,
IsPropertyVerified = p.IsPropertyVerified,
IsPropertyNotified = p.IsPropertyNotified,
MainPicSrc = pp.Where(e => e.MainPic == true).FirstOrDefault().PhotoLocation,
PhotosCount = pp.Count(),
Price = p.Price,
NoOfBedrooms = p.NoOfBedrooms,
Area = a.AreaLookUpDescription,
ShortDescription = (p.Description.Length > 300) ? p.Description.Substring(0, 300) : p.Description,
LatestCalendarEvent = c.OrderByDescending(e => e.DateSaved).FirstOrDefault()
};
return addedProperties.ToList();
I want to make recursive category menu for product categories on my web page.Each category must retrieve related first item according to CategoryId on "Product" table but this category should be disappear if category hasn't any product.Actually, i can make to easily with using INNER JOIN for non-recursive category menu.How can i solve this issue?Is there any idea?
I can use a method as follow but this method both amateur and may be null first item.
Category table
+--------------+---------------+------------+
| CategoryId | CategoryName | ParentId |
+--------------+---------------+------------+
| 1 | Cookware | NULL |
+--------------+---------------+------------+
| 2 | Tableware | NULL |
+--------------+---------------+------------+
| 3 | Teapots | 1 |
+--------------+---------------+------------+
| 4 | Cutleries | 3 |
+--------------+---------------+------------+
| 5 | 30pcs Cutlery | 2 |
+--------------+---------------+------------+
Product table
+--------------+--------------+--------------------+------------+
| ProductId | ProductCode | ProductName | CategoryId |
+--------------+--------------+--------------------+------------+
| 1 | G110090 | Teapot | 3 |
+--------------+--------------+--------------------+------------+
| 2 | D220623 | Cutlery Set | 5 |
+--------------+--------------+--------------------+------------+
RecursiveCategory method
public string RecursiveCategory(IEnumerable<Category> category, int? parent)
{
string catNode = string.Empty;
if(category.Any(n=>n.ParentId == parent))
{
catNode += "<ul>";
foreach(Category c in category)
{
catNode += "<li>";
catNode += "<a href='/Detail/" + GetFirstItem(c.CategoryId).ProductId + "'>"+c.CategoryName+"</a>";
catNode += RecursiveCategory(category, c.ParentId);
catNode += "</li>";
}
catNode += "</ul>"
}
return catNode;
}
GetFirstItem method
public Product GetFirstItem(int categoryId)
{
Product prod = new Product();
foreach(Product p in db.Product.Where(n=>n.CategoryId == categoryId))
{
prod.ProductId = p.ProductId;
prod.ProductName = p.ProductName;
...
}
return prod;
}
Try this to construct a hierarchy from a given point (using null in the first call will give you the full tree with the products for each category). As a modification you could make product lazy load if you need to:
public class Category
{
IEnumerable<Category> Children {get;set;}
IEnumerable<Product> Products {get;set;}
}
public IEnumerable<Category> GetCategory(int? parent)
{
var result = new List<Category>();
foreach (var cat in categories.Where(p => p.parentId = parent)
{
var generatedCategory = new Category();
generatedCategory.Children = GetCategory(cat.id);
generatedCategory.Products = products.Where(p => p.CategoryId = cat.CategoryId);
result.Add(generatedCategory);
}
return result;
}
Note: I haven't tested the code just a guide about how to construct it easily.