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LINQtoSQL語(yǔ)句經(jīng)驗(yàn)總結(jié)
LINQ to SQL有很多值得學(xué)習(xí)的地方，這里我們主要介紹LINQ to SQL語(yǔ)句，包括介紹一對(duì)多關(guān)系和多對(duì)多關(guān)系等方面。
LINQ to SQL語(yǔ)句簡(jiǎn)單形式
說(shuō)明：new一個(gè)對(duì)象，使用InsertOnSubmit方法將其加入到對(duì)應(yīng)的集合中，使用SubmitChanges()提交到數(shù)據(jù)庫(kù)。
- NorthwindDataContext db = new NorthwindDataContext();
- var newnewCustomer = new Customer
- {
- CustomerID = "MCSFT",
- CompanyName = "Microsoft",
- ContactName = "John Doe",
- ContactTitle = "Sales Manager",
- Address = "1 Microsoft Way",
- City = "Redmond",
- Region = "WA",
- PostalCode = "98052",
- Country = "USA",
- Phone = "(425) 555-1234",
- Fax = null
- };
語(yǔ)句描述：使用InsertOnSubmit方法將新客戶添加到Customers 表對(duì)象。調(diào)用SubmitChanges 將此新Customer保存到數(shù)據(jù)庫(kù)。
LINQ to SQL語(yǔ)句一對(duì)多關(guān)系
說(shuō)明：Category與Product是一對(duì)多的關(guān)系，提交Category(一端)的數(shù)據(jù)時(shí)，LINQ to SQL會(huì)自動(dòng)將Product(多端)的數(shù)據(jù)一起提交。
- var newnewCategory = new Category
- {
- CategoryName = "Widgets",
- Description = "Widgets are the ……"
- };
- var newnewProduct = new Product
- {
- ProductName = "Blue Widget",
- UnitPrice = 34.56M,
- Category = newCategory
- };
語(yǔ)句描述：使用InsertOnSubmit方法將新類(lèi)別添加到Categories表中，并將新Product對(duì)象添加到與此新Category有外鍵關(guān)系的Products表中。調(diào)用SubmitChanges將這些新對(duì)象及其關(guān)系保存到數(shù)據(jù)庫(kù)。
LINQ to SQL語(yǔ)句多對(duì)多關(guān)系
說(shuō)明：在多對(duì)多關(guān)系中，我們需要依次提交。
- var newnewEmployee = new Employee
- {
- FirstName = "Kira",
- LastName = "Smith"
- };
- var newnewTerritory = new Territory
- {
- TerritoryID = "12345",
- TerritoryDescription = "Anytown",
- Region = db.Regions.First()
- };
- var newnewEmployeeTerritory = new EmployeeTerritory
- {
- Employee = newEmployee,
- Territory = newTerritory
- };
網(wǎng)頁(yè)標(biāo)題：LINQtoSQL語(yǔ)句經(jīng)驗(yàn)總結(jié)
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