Entity Framework Code First 對應規則設定

Oct 27, 2014

4 mins read

Code First Entity Framework
Code first Entity framework

要改變預設對應規則，可以用兩種方式 一種是使用Attributes的方式，例如[key] 一種是覆寫DbContext的OnModelCreating，透過DbModelBuilder使用Fluent API方式來設定

資料表名稱和主索引

[Table("Table1")]
public class Table1
{
    [Key]
    public int id { get; set; }
}

public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; x.id);
}



}
自動編號

[Table("Table1")]
public class Table1
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int id { get; set; }
}

public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; x.id);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.id)
        .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
}



}
欄位名稱 
[Table(“Table1”)]
public class Table1
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
[Column(“sid”)]
public int id { get; set; }
}


public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; x.id);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.id)
        .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
        .HasColumnName("sid");
}



}
欄位型態

[Table("Table1")]
public class Table1
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Column("sid", TypeName = "bigint")]
    public int id { get; set; }
}

public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; x.id);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.id)
        .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
        .HasColumnName("sid")
        .HasColumnType("bigint");
}



}
不可為空(文字)

[Table("Table1")]
public class Table1
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Column("sid", TypeName = "bigint")]
    public int id { get; set; }

[Required]
public string s1 { get; set; }



}


public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; x.id);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.id)
        .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
        .HasColumnName("sid")
        .HasColumnType("bigint");
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.s1)
        .IsRequired();
}



}
最大長度(文字)

[Table("Table1")]
public class Table1
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Column("sid", TypeName = "bigint")]
    public int id { get; set; }

[Required]
[MaxLength(10)]
public string s1 { get; set; }



}


public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; x.id);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.id)
        .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
        .HasColumnName("sid")
        .HasColumnType("bigint");
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.s1)
        .IsRequired()
        .HasMaxLength(10);
}



}
varchar, char(文字)

[Table("Table1")]
public class Table1
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Column("sid", TypeName = "bigint")]
    public int id { get; set; }

[Required]
[MaxLength(10)]
[Column(TypeName="char")]
public string s1 { get; set; }



}


public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; x.id);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.id)
        .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
        .HasColumnName("sid")
        .HasColumnType("bigint");
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.s1)
        .IsRequired()
        .HasMaxLength(10)
        .IsFixedLength()
        .IsUnicode(false);
}



}
精準度(浮點數)

[Table("Table1")]
public class Table1
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Column("sid", TypeName = "bigint")]
    public int id { get; set; }

[Required]
[MaxLength(10)]
[Column(TypeName="char")]
public string s1 { get; set; }

public decimal c1 { get; set; }



}


public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; x.id);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.id)
        .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
        .HasColumnName("sid")
        .HasColumnType("bigint");
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.s1)
        .IsRequired()
        .HasMaxLength(10)
        .IsFixedLength()
        .IsUnicode(false);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.c1)
        .HasPrecision(18, 2);
}



}
時間戳記

[Table("Table1")]
public class Table1
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Column("sid", TypeName = "bigint")]
    public int id { get; set; }

[Required]
[MaxLength(10)]
[Column(TypeName = "char")]
public string s1 { get; set; }

public decimal c1 { get; set; }

[Timestamp]
public byte[] t1 { get; set; }



}


public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; x.id);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.id)
        .HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
        .HasColumnName("sid")
        .HasColumnType("bigint");
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.s1)
        .IsRequired()
        .HasMaxLength(10)
        .IsFixedLength()
        .IsUnicode(false);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.c1)
        .HasPrecision(18, 2);
    modelBuilder.Entity&lt;Table1&gt;().Property(x =&gt; x.t1)
        .IsRowVersion();
}



}
複合索引

[Table("Table1")]
public class Table1
{
    [Key]
    [Column(Order = 1)]
    public int id1 { get; set; }

[Key]
[Column(Order = 2)]
public int id2 { get; set; }



}


public class DemoContext : DbContext
{
public DbSet<Table1> Table1 { get; set; }


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity&lt;Table1&gt;().ToTable("Table1").HasKey(x =&gt; new { x.id1, x.id2 });
}



}

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