Viastudy ef core_cheat_sheet

Viastudy ef core_cheat_sheet

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  Entity Framework CoreCheat Sheet 1 Viastudy.com Platforms .NET Framework (Console, Winform, WPF, ASP.NET) .NET Core (Console, ASP.NET Core) Mono & Xamarin (in-progress) UWP (in-progress) EF Core - Working with DbContext Create and use DbContext object using (var context = new SchoolContext()) { //work with context here } Create Operation context.Add<Student>(newStudentObj); context.SaveChanges() //or context.Students.Add(newStudentObj); context.SaveChanges(); // or context.Entry(newStudentObj).State = EntityState.Added; context.SaveChanges(); Update Operation context.Update<Student>(StudentObj); context.SaveChanges(); //or context.Entry(studentObj).State = EntityState.Modified; context.SaveChanges(); Delete Operation Context.Remove(studentObj); context.SaveChanges(); //or context.Entry(studentObj).State = EntityState.Deleted; context.SaveChanges(); Get the current State of an entity varstate = context.Entry<Student>(studentObj).State; Execute raw SQL query for entity types varsList = context.Students.FromSql($"Select * from Student where StudentName=’name’").ToList<Student>(); Execute raw SQL commands int noOfRowsAffected = context.Database.ExecuteSqlCommand("CUD command"); Explicitly load navigation /reference entity context.Entry(student).Reference(s => s.Grade).Load(); Explicitly Load Collection context.Entry(student).Collection(s=>s.Courses).Load(); Find by PrimaryKey var student = context.Students.Find(1); Disable automatic detect changes context.ChangeTracker.AutoDetectChangesEnabled = false Disable Query Tracking context.ChangeTracker.QueryTrackingBehavior = QueryTrackingBehavior.NoTracking; Disable Automatic Detect Changes context.ChangeTracker.AutoDetectChangesEnabled = false; Eager Loading context.Students.Where(s => s.FirstName == "Bill") .Include(s => s.Grade).FirstOrDefault(); Multi Level Eager Loading context.Students.Where(s => s.FirstName == "Bill") .Include(s => s.Grade) .ThenInclude(g => g.Teachers); EF Core Conventions Schema dbo Table Name Same as DbSet<TEntity> property name in the context class. Primary key Name 1) Id 2) <Entity Class Name> Id (case insensitive) e.g. Id or StudentId property becomes primary key of Student by default. Foreign key property Name EF Core API will create a foreign key column for each reference navigation property in an entity with one of the following naming patterns. 1. <Reference Navigation Property Name>Id 2. <Reference Navigation Property Name><Principal Primary Key Property Name> Null column All reference type properties and nullable primitive properties. NotNull Column PrimaryKey properties and non-nullable primitive properties (int, decimal, datetime, float etc.) Index Clustered index on PrimaryKey columns. Non-clustered index on Foreignkey columns. Properties mapping to DB By default all properties will map to database. Cascade delete Enabled by default. EF Core Fluent API - Entity Type Configurations ToTable() - Maps an entity to database table modelBuilder.Entity<Student>().ToTable("StudentInfo"); modelBuilder.Entity<Student>() .ToTable("StudentInfo", "dbo"); ToTable() – Maps two entities to one database table modelBuilder.Entity<Student>().ToTable("Student"); modelBuilder.Entity<StudentDeail>() .ToTable("Student"); HasKey() - Configures Primary Key(s) modelBuilder.Entity<Student>().HasKey(s => s.StudId); HasAlternateKey() - Configures an alternate key in the EF model modelBuilder.Entity<Student>().HasAlternateKey(s=>s.Id)
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  Entity Framework CoreCheat Sheet 2 Viastudy.com HasIndex() - Configures an index on the specified properties modelBuilder.Entity<Student>().HasIndex(s => s.Id) HasOne() - Configures the One part of the relationship modelBuilder.Entity<Student>().HasOne(s => s.Grade) HasMany() - Configures the Many part of the relationship modelBuilder.Entity<Student>().HasMany(s => s.Courses) OwnsOne() - Configures a relationship where the target entity is owned by this entity modelBuilder.Entity<Student>() .OwnsOne(p => p.HomeAddress) .OwnsOne(p => p.PermanentAddress); EF Core Fluent API – Property Configuration HasColumnType - Configures a column data type modelBuilder.Entity<Student>() .Property(s => s.StudentName) .HasColumnType("varchar"); HasColumnName - Configures a Column name modelBuilder.Entity<Student>() .Property(s => s.StudentName) .HasColumnName("Name"); HasDefaultValue - Configures a default value modelBuilder.Entity<Student>() .Property(s => s.PendingFees) .HasDefaultValue(100); HasComputedColumnSql - Configures a computed column modelBuilder.Entity<Student>() .Property(s => s.PendingFees) .HasComputedColumnSql(“Sql here”); IsRequired - Configures a Null column modelBuilder.Entity<Student>().Property(s => s.DoB).IsRequired(false); IsRequired - Configures a NotNull column modelBuilder.Entity<Student>() .Property(s => s.DoB) .IsRequired(); HasMaxLength - Configures maximum Length for string column modelBuilder.Entity<Student>() .Property(s => s.StudentName) .HasMaxLength(50); IsUnicode - Configures a Unicode string column modelBuilder.Entity<Student>() .Property(s => s.StudentName) .IsUnicode(); //or modelBuilder.Entity<Student>() .Property(s => s.StudentName) .IsUnicode(false); IsConcurrencyToken – Configures a concurrency property modelBuilder.Entity<Student>() .Property(p => p.StudentName) .IsConcurrencyToken(); //or modelBuilder.Entity<Student>() .Property(p => p.RowVersion) .IsRowVersion(); HasField - Configures a backing field modelBuilder.Entity<Student>() .Property(s => s.StudentName) .HasField("_StudentName"); EF Core Fluent API – Relationship Configurations One-to-zero-or-one modelBuilder.Entity<Student>() .HasOne<StudentAddress>(s => s.Address) .WithOne(ad => ad.Student) One-to-Many modelBuilder.Entity<Student>() .HasOne<Grade>(s => s.Grade) .WithMany(g => g.Students) Many-to-Many modelBuilder.Entity<StudentCourse>() .HasKey(sc => new { sc.StudentId, sc.CourseId }); modelBuilder.Entity<StudentCourse>() .HasOne<Student>(sc => sc.Student) .WithMany(s => s.StudentCourses); modelBuilder.Entity<StudentCourse>() .HasOne<Course>(sc => sc.Course) .WithMany(s => s.StudentCourses);
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  Entity Framework CoreCheat Sheet 3 Viastudy.com Features EF Core DB-First - Command line 1.0 DB-First -VS Wizard X Identity Key Generation 1.0 Global query filter 2.0 DB Scalar function 2.0 Model-First X Code-First 1.0 Mixed client/server evaluation 1.0 DbContext & DbSet 1.0 LINQ-to-Entities 1.0 ChangeTracker 1.0 Automated Migration X Code-based Migration 1.0 Eager Loading 1.0 Proxy Entity X Interception X Simple Logging X GroupBy Transaction 2.1 Graphical Visualization X of EDM Raw SQL Queries: Entity Types 1.0 EDM Wizard X Raw SQL Queries: non- 2.1 Querying using EntitySQL X entity types DbContext Pooling 2.0 Table per hierarchy 1.0 Table per type X Data annotations 1.0 Fluent API 1.0 Table per concrete class X Model Format: EDMX X Many-to-Many without X join entity (XML) Entity Splitting X Spatial Data X Lazy loading 2.1 Stored procedure mapping with entity for X CUD operation Seed Data 2.1 Complex Type/Owned X types Table splitting 2.0 Field Mapping 1.1 Shadow properties 1.0 Alternate Keys 1.0