NetCore + Mysql + EF:No coercion operator is defined between types 'System.Int16' and 'System.Boolea...

总结三种解决办法：

1.Mysql升级到7

 

2.Nuget安装Pomelo.EntityFrameworkCore.MySql 2.2.0替代MySql.Data.EntityFrameworkCore 8.0.16后正常.

  PS：如果使用Pomelo库的SQL语句查询Convert.ToDateTime(item["createtime"]).ToString("yyyy-MM-dd HH:mm:ss")会报Unable to cast object of type 'MySql.Data.Types.MySqlDateTime' to type 'System.IConvertible'.  要改成Convert.ToDateTime(item["dskuupdatetime"].ToString()).ToString("yyyy-MM-dd HH:mm:ss").

 

3.EF上下文添加转换代码

 1 protected override void OnModelCreating(ModelBuilder builder)
 2 {
 3             base.OnModelCreating(builder);
 4 
 5             foreach (var entityType in builder.Model.GetEntityTypes())
 6             {
 7                 foreach (var property in entityType.GetProperties())
 8                 {
 9                     if (property.ClrType == typeof(bool))
10                     {
11                         property.SetValueConverter(new BoolToIntConverter());
12                     }
13                 }
14             }
15 }

 1 public class BoolToIntConverter : ValueConverter<bool, int>
 2     {
 3         public BoolToIntConverter( ConverterMappingHints mappingHints = null)
 4             : base(
 5                   v => Convert.ToInt32(v),
 6                   v => Convert.ToBoolean(v),
 7                   mappingHints)
 8         {
 9         }
10 
11         public static ValueConverterInfo DefaultInfo { get; }
12             = new ValueConverterInfo(typeof(bool), typeof(int), i => new BoolToIntConverter(i.MappingHints));
13     }

 

PS: Linq Any转换失败：

　　　　var isExist = db.MyDbTable.Any(o => o.Id == id);

　　　　//throw No coercion operator is defined between types 'System.Int16' and 'System.Boolean',

              要改成

              var isExist = db.MyDbTable.FirstOrDefault(o => o.Id == id) != null;

     对于Linq Any有其他解决办法吗？

 

转载于:https://www.cnblogs.com/ZpfCoder/p/10968026.html