说我有以下型号：
[Table("Record")]
public class RecordModel
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
[Display(Name = "Record Id")]
public int RecordId { get; set; }
[StringLength(150)]
public string Name { get; set; }
[required]
[StringLength(15)]
public string IMEI { get; set; }
}
解决方法
根据这个链接：
Creating Indexes via Data Annotations with Entity Framework 5.0
你应该写一些类型的扩展代码：
你应该写一些类型的扩展代码：
using System;
[AttributeUsage(AttributeTargets.Property,Inherited = false,AllowMultiple = true)]
public class IndexAttribute : Attribute
{
public IndexAttribute(string name,bool unique = false)
{
this.Name = name;
this.IsUnique = unique;
}
public string Name { get; private set; }
public bool IsUnique { get; private set; }
}
和第二类：
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;
using System.Linq;
using System.Reflection;
public class IndexInitializer<T> : IDatabaseInitializer<T> where T : DbContext
{
private const string CreateIndexQueryTemplate = "CREATE {unique} INDEX {indexName} ON {tableName} ({columnName})";
public void InitializeDatabase(T context)
{
const BindingFlags PublicInstance = BindingFlags.Public | BindingFlags.Instance;
foreach (var dataSetProperty in typeof(T).GetProperties(PublicInstance).Where(
p => p.PropertyType.Name == typeof(DbSet<>).Name))
{
var entityType = dataSetProperty.PropertyType.GetGenericArguments().Single();
TableAttribute[] tableAttributes = (TableAttribute[])entityType.GetCustomAttributes(typeof(TableAttribute),false);
foreach (var property in entityType.GetProperties(PublicInstance))
{
IndexAttribute[] indexAttributes = (IndexAttribute[])property.GetCustomAttributes(typeof(IndexAttribute),false);
NotMappedAttribute[] notMappedAttributes = (NotMappedAttribute[])property.GetCustomAttributes(typeof(NotMappedAttribute),false);
if (indexAttributes.Length > 0 && notMappedAttributes.Length == 0)
{
ColumnAttribute[] columnAttributes = (ColumnAttribute[])property.GetCustomAttributes(typeof(ColumnAttribute),false);
foreach (var indexAttribute in indexAttributes)
{
string indexName = indexAttribute.Name;
string tableName = tableAttributes.Length != 0 ? tableAttributes[0].Name : dataSetProperty.Name;
string columnName = columnAttributes.Length != 0 ? columnAttributes[0].Name : property.Name;
string query = CreateIndexQueryTemplate.Replace("{indexName}",indexName)
.Replace("{tableName}",tableName)
.Replace("{columnName}",columnName)
.Replace("{unique}",indexAttribute.IsUnique ? "UNIQUE" : string.Empty);
context.Database.CreateIfNotExists();
context.Database.ExecutesqlCommand(query);
}
}
}
}
}
}
之后,您可以使用您的索引：
[required] [Index("IMEIIndex",unique: true)] [StringLength(15)] public string IMEI { get; set; }
