Question

我的DataBase中有两个表BUNTS，其中包含有关钢件的信息

CREATE TABLE BUNTS (
    BUNTCODE         INTEGER NOT NULL,
    BUNTNAME         VARCHAR(20),
    BUNTSTEEL        INTEGER,
    ......
);

和POLL_WEIGHT_BUNTS，其中包含有关对每个短信执行的操作的信息

CREATE TABLE POLL_WEIGHT_BUNTS (
    PWBCODE            INTEGER NOT NULL,
    PWBBUNTCODE        INTEGER,
    PWBDEPARTMENTFROM  INTEGER,
    PWBDEPARTMENTTO    INTEGER
    ....
);

这种关系是一对多的。我将这些表映射到模型。一切都很好。最近我决定在表BUNTS中添加一个字段，该字段将引用最后一次对bunt执行的操作：

BUNTLASTOPER     INTEGER

现在我的模型看起来像这样：

[Table("BUNTS")]
public class Bunt
{
    [Key]
    [Column("BUNTCODE")]
    public int? Code { set; get; }
    [Column("BUNTNAME")]
    public string Name { set; get; }
    [Column("BUNTSTEEL")]
    public int? SteelCode { set; get; }
    [Column("BUNTLASTOPER")]
    public int? LastOperationID { set; get; }
    [ForeignKey("LastOperationID")]
    public BuntOperation LastOperation { set; get; }
    public virtual ICollection<BuntOperation> Operations { set; get; }
}

[Table("POLL_WEIGHT_BUNTS")]
public class BuntOperation
{
    [Key]
    [Column("PWBCODE")]
    public int? Code { set; get; }
    [Column("PWBBUNTCODE")]
    public int? BuntCode { set; get; }
    [ForeignKey("BuntCode")]
    public Bunt Bunt { set; get; }
    [Column("PWBDEPARTMENTFROM")]
    public int? DepartmentFromCode { set; get; }
    .....
}

在我完成此操作后，当我尝试查询此类操作时

return _context.Operations;

它生成一个带有新的错误字段Bunt_Code

的SQL语句

SELECT 
"B"."PWBCODE" AS "PWBCODE", 
"B"."PWBBUNTCODE" AS "PWBBUNTCODE", 
"B"."PWBDEPARTMENTFROM" AS "PWBDEPARTMENTFROM", 
....
"B"."Bunt_Code" AS "Bunt_Code"
FROM   "POLL_WEIGHT_BUNTS" AS "B"

我假设现在EF查找的字段是BUNTS表的外键，并且无法找到它。因此它生成Bunt_Code字段，我的数据库中缺少该字段。但是我在Bunt类中已经有一个属性BuntOperation，它引用了BUNTS表。我错过了什么？

UPDATE 似乎这解决了我的问题

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<Bunt>().HasOptional(b => b.LastOperation).WithMany();
    modelBuilder.Entity<Bunt>().HasMany(b => b.Operations).WithRequired(op => op.Bunt);
}

Answer 1

似乎这解决了我的问题

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
     modelBuilder.Entity<Bunt>().HasOptional(b => b.LastOperation).WithMany();
     modelBuilder.Entity<Bunt>().HasMany(b => b.Operations).WithRequired(op => op.Bunt);
}

实体框架建议无效的字段名称

1 个答案: