我正在尝试编写一个查询来让系统中的用户拥有他/她的所有角色.用户和角色之间存在多对多关系. joiner表是SystemUserUserRole,其中包含UserId和RoleId列.我的模型如下:
SystemUser模型
[Key] public int UserId { get; set; } [required] [MaxLength(75)] public string FirstName { get; set; } [required] [MaxLength(75)] public string LastName { get; set; } [required] [MaxLength(15)] public string Phone { get; set; } [required] [MaxLength(250)] public string Email { get; set; } public virtual List<UserRole> UserRoles { get; set; }
UserRole模型
[Key] public int RoleId { get; set; } [required] [MaxLength(250)] public string RoleName { get; set; } public virtual List<SystemUser> SystemUsers { get; set; }
我想在下面做一些没有运气的事情.关于我做错了什么的任何建议.
string query = "SELECT u.*,r.* FROM SystemUser u INNER JOIN SystemUserUserRole ur ON u.UserId = ur.UserId INNER JOIN UserRole r on ur.RoleId = r.RoleId WHERE Email = @email AND IsActive = true;"; SystemUser user = con.Query<SystemUser,UserRole,SystemUser>(query,(SystemUser,UserRole) => { SystemUser.UserRoles = UserRole; return SystemUser; }).First();
解决方法
这将有效:
public SystemUser() { UserRoles = new List<UserRole>(); }
然后告诉Dapper,对于每个连接的行,UserRole应该添加到SystemUser.UserRoles:
SystemUser user = con.Query<SystemUser,UserRole) => { SystemUser.UserRoles.Add(UserRole); return SystemUser; },splitOn: "RoleId").First();
请注意,最后一部分是添加splitOn参数,因为Dapper期望将标识列命名为Id,否则您需要明确地告诉它列名.