Dapper关联查询

时间:2023-03-09 22:53:00
Dapper关联查询

1、一对一:

  using (IDbConnection connecton = new MySqlConnection(ConfigurationManager.ConnectionStrings["default"].ConnectionString))
{
string sql = @"SELECT *
from expand_userbasicinformation b
JOIN expand_users u on b.UserId = u.UserId";
var infos = connecton.Query<UserInfo, User, UserInfo>(sql, (info, user) =>
{
info.User = user;
return info;
}, splitOn: "UserId");
}

其中,实体定义如下:

  public class UserInfo
{
public string InformationId { get; set; } public string UserId { get; set; } public User User { get; set; } public string RealName { get; set; }
} public class User
{
public string UserId { get; set; } public string LoginName { get; set; } public string LoginPassword { get; set; }
}

2、一对多:

using (IDbConnection connecton = new MySqlConnection(ConfigurationManager.ConnectionStrings["crmcontroller"].ConnectionString))
{
List<Client> clients = new List<Client>();
string sql = @"SELECT *
from crm_client_list
join crm_client_field_value on ClientId = ModelId";
var infos = connecton.Query<Client, ClientField, Client>(sql, (c, f) =>
{
var currentClient = clients.Find(x => x.ClientId == c.ClientId);
if (currentClient == null)
{
c.Fields.Add(f);
clients.Add(c);
return c;
}
else
{
currentClient.Fields.Add(f);
return currentClient;
}
}, splitOn: "ModelId");
}

其中,实体定义如下:

  public class Client
{
public Client()
{
this.Fields = new List<ClientField>();
} public string ClientId { get; set; } public string Name { get; set; } public string PhoneNumber { get; set; } public string IDNumber { get; set; } public List<ClientField> Fields { get; private set; }
} public class ClientField
{
public string FieldValueId { get; set; } public string ModelId { get; set; } public string FieldId { get; set; } public string FieldValue { get; set; }
}