与实体框架核心删除dbData.Database。我找不到一个解决方案来构建一个原始的SQL查询为我的全文搜索查询，将返回表数据和排名。
我所见过的在实体框架核心中构建原始SQL查询的唯一方法是通过dbData.Product。FromSql(“SQL脚本”);这是没有用的，因为我没有DbSet，将映射我在查询中返回的排名。
有什么想法?
当前回答
这样做的实体框架核心5，需要安装
Microsoft.EntityFrameworkCore.Relational
助手扩展方法
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.Storage;
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
public static class EfHelper
{
public static DbTransaction GetDbTransaction(this IDbContextTransaction source)
{
return (source as IInfrastructure<DbTransaction>).Instance;
}
private class PropertyMapp
{
public string Name { get; set; }
public Type Type { get; set; }
public bool IsSame(PropertyMapp mapp)
{
if (mapp == null)
{
return false;
}
bool same = mapp.Name == Name && mapp.Type == Type;
return same;
}
}
public static IEnumerable<T> FromSqlQuery<T>(this DbContext context, string query, params object[] parameters) where T : new()
{
const BindingFlags flags = BindingFlags.Public | BindingFlags.Instance | BindingFlags.NonPublic;
List<PropertyMapp> entityFields = (from PropertyInfo aProp in typeof(T).GetProperties(flags)
select new PropertyMapp
{
Name = aProp.Name,
Type = Nullable.GetUnderlyingType(aProp.PropertyType) ?? aProp.PropertyType
}).ToList();
List<PropertyMapp> dbDataReaderFields = new List<PropertyMapp>();
List<PropertyMapp> commonFields = null;
using (var command = context.Database.GetDbConnection().CreateCommand())
{
if (command.Connection.State != ConnectionState.Open)
{
command.Connection.Open();
}
var currentTransaction = context.Database.CurrentTransaction;
if (currentTransaction != null)
{
command.Transaction = currentTransaction.GetDbTransaction();
}
command.CommandText = query;
if (parameters.Any())
{
command.Parameters.AddRange(parameters);
}
using (var result = command.ExecuteReader())
{
while (result.Read())
{
if (commonFields == null)
{
for (int i = 0; i < result.FieldCount; i++)
{
dbDataReaderFields.Add(new PropertyMapp { Name = result.GetName(i), Type = result.GetFieldType(i) });
}
commonFields = entityFields.Where(x => dbDataReaderFields.Any(d => d.IsSame(x))).Select(x => x).ToList();
}
var entity = new T();
foreach (var aField in commonFields)
{
PropertyInfo propertyInfos = entity.GetType().GetProperty(aField.Name);
var value = (result[aField.Name] == DBNull.Value) ? null : result[aField.Name]; //if field is nullable
propertyInfos.SetValue(entity, value, null);
}
yield return entity;
}
}
}
}
/*
* https://entityframeworkcore.com/knowledge-base/35631903/raw-sql-query-without-dbset---entity-framework-core
*/
public static IEnumerable<T> FromSqlQuery<T>(this DbContext context, string query, Func<DbDataReader, T> map, params object[] parameters)
{
using (var command = context.Database.GetDbConnection().CreateCommand())
{
if (command.Connection.State != ConnectionState.Open)
{
command.Connection.Open();
}
var currentTransaction = context.Database.CurrentTransaction;
if (currentTransaction != null)
{
command.Transaction = currentTransaction.GetDbTransaction();
}
command.CommandText = query;
if (parameters.Any())
{
command.Parameters.AddRange(parameters);
}
using (var result = command.ExecuteReader())
{
while (result.Read())
{
yield return map(result);
}
}
}
}
}
模型
public class UserModel
{
public string Name { get; set; }
public string Email { get; set; }
public bool? IsDeleted { get; set; }
}
手动映射
List<UserModel> usersInDb = Db.FromSqlQuery
(
"SELECT Name, Email FROM Users WHERE Name=@paramName",
x => new UserModel
{
Name = (string)x[0],
Email = (string)x[1]
},
new SqlParameter("@paramName", user.Name)
)
.ToList();
usersInDb = Db.FromSqlQuery
(
"SELECT Name, Email FROM Users WHERE Name=@paramName",
x => new UserModel
{
Name = x["Name"] is DBNull ? "" : (string)x["Name"],
Email = x["Email"] is DBNull ? "" : (string)x["Email"]
},
new SqlParameter("@paramName", user.Name)
)
.ToList();
使用反射自动映射
List<UserModel> usersInDb = Db.FromSqlQuery<UserModel>
(
"SELECT Name, Email, IsDeleted FROM Users WHERE Name=@paramName",
new SqlParameter("@paramName", user.Name)
)
.ToList();
其他回答
我找到了EntityFrameworkCore包。RawSQLExtensions在github上。要使用它，添加nuget包。
<PackageReference Include="EntityFrameworkCore.RawSQLExtensions" Version="1.2.0" />
这个库没有文档，但下面是我在。net 6 + EF Core 6 + Npgsql 6中使用它
public class DbResult
{
public string Name { get; set; }
public int Age { get; set; }
}
using EntityFrameworkCore.RawSQLExtensions.Extensions;
var results = await context.Database
.SqlQuery<DbResult>(
@"select name, age from ""users"" where age > @Age",
new NpgsqlParameter("@Age", 15))
.ToListAsync();
在Core 2.1中，你可以这样做:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Query<Ranks>();
}
然后定义SQL过程，像这样:
public async Task<List<Ranks>> GetRanks(string value1, Nullable<decimal> value2)
{
SqlParameter value1Input = new SqlParameter("@Param1", value1?? (object)DBNull.Value);
SqlParameter value2Input = new SqlParameter("@Param2", value2?? (object)DBNull.Value);
List<Ranks> getRanks = await this.Query<Ranks>().FromSql("STORED_PROCEDURE @Param1, @Param2", value1Input, value2Input).ToListAsync();
return getRanks;
}
这样就不会在数据库中创建rank模型。
现在在你的控制器/动作中你可以调用:
List<Ranks> gettingRanks = _DbContext.GetRanks(value1,value2).Result.ToListAsync();
这样就可以调用原始SQL过程。
我使用Dapper绕过了Entity框架Core的这个约束。
IDbConnection.Query
正在处理带有多个参数的SQL查询或存储过程。 顺便说一下，它更快一些(参见基准测试)
Dapper很容易学。编写和运行带参数的存储过程需要15分钟。无论如何，你可以同时使用EF和Dapper。下面是一个例子:
public class PodborsByParametersService
{
string _connectionString = null;
public PodborsByParametersService(string connStr)
{
this._connectionString = connStr;
}
public IList<TyreSearchResult> GetTyres(TyresPodborView pb,bool isPartner,string partnerId ,int pointId)
{
string sqltext "spGetTyresPartnerToClient";
var p = new DynamicParameters();
p.Add("@PartnerID", partnerId);
p.Add("@PartnerPointID", pointId);
using (IDbConnection db = new SqlConnection(_connectionString))
{
return db.Query<TyreSearchResult>(sqltext, p,null,true,null,CommandType.StoredProcedure).ToList();
}
}
}
试试这个(创建扩展方法)
public static List<T> ExecuteQuery<T>(this dbContext db, string query) where T : class, new()
{
using (var command = db.Database.GetDbConnection().CreateCommand())
{
command.CommandText = query;
command.CommandType = CommandType.Text;
db.Database.OpenConnection();
using (var reader = command.ExecuteReader())
{
var lst = new List<T>();
var lstColumns = new T().GetType().GetProperties(BindingFlags.DeclaredOnly | BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic).ToList();
while (reader.Read())
{
var newObject = new T();
for (var i = 0; i < reader.FieldCount; i++)
{
var name = reader.GetName(i);
PropertyInfo prop = lstColumns.FirstOrDefault(a => a.Name.ToLower().Equals(name.ToLower()));
if (prop == null)
{
continue;
}
var val = reader.IsDBNull(i) ? null : reader[i];
prop.SetValue(newObject, val, null);
}
lst.Add(newObject);
}
return lst;
}
}
}
用法:
var db = new dbContext();
string query = @"select ID , Name from People where ... ";
var lst = db.ExecuteQuery<PeopleView>(query);
我的模型:(不在DbSet中):
public class PeopleView
{
public int ID { get; set; }
public string Name { get; set; }
}
在。net core 2.2和3.0中测试。
注意:该方案性能较慢
查询数据:不存在实体
string query = "SELECT r.Name as roleName, ur.roleId, u.Id as userId FROM dbo.AspNetUserRoles AS ur INNER JOIN dbo.AspNetUsers AS u ON ur.UserId = u.Id INNER JOIN dbo.AspNetRoles AS r ON ur.RoleId = r.Id ";
ICollection<object> usersWithRoles = new List<object>();
using (var command = _identityDBContext.Database.GetDbConnection().CreateCommand())
{
command.CommandText = query;
command.CommandType = CommandType.Text;
await _identityDBContext.Database.OpenConnectionAsync();
using (var reader = await command.ExecuteReaderAsync())
{
while (await reader.ReadAsync())
{
usersWithRoles.Add(new {
roleName = reader.GetFieldValueAsync<string>(0).Result,
roleId = reader.GetFieldValueAsync<string>(1).Result,
userId = reader.GetFieldValueAsync<string>(2).Result
});
}
}
}
详细:
[HttpGet]
[Route("GetAllUsersWithRoles")]
public async Task<IActionResult> GetAllUsersWithRoles()
{
string query = "SELECT r.Name as roleName, ur.roleId, u.Id as userId FROM dbo.AspNetUserRoles AS ur INNER JOIN dbo.AspNetUsers AS u ON ur.UserId = u.Id INNER JOIN dbo.AspNetRoles AS r ON ur.RoleId = r.Id ";
try
{
ICollection<object> usersWithRoles = new List<object>();
using (var command = _identityDBContext.Database.GetDbConnection().CreateCommand())
{
command.CommandText = query;
command.CommandType = CommandType.Text;
await _identityDBContext.Database.OpenConnectionAsync();
using (var reader = await command.ExecuteReaderAsync())
{
while (await reader.ReadAsync())
{
usersWithRoles.Add(new {
roleName = reader.GetFieldValueAsync<string>(0).Result,
roleId = reader.GetFieldValueAsync<string>(1).Result,
userId = reader.GetFieldValueAsync<string>(2).Result
});
}
}
}
return StatusCode(200, usersWithRoles); // Get all users
}
catch (Exception e)
{
return StatusCode(500, e);
}
}
结果如下所示:
[
{
"roleName": "admin",
"roleId": "7c9cb1be-e987-4ec1-ae4d-e4c9790f57d8",
"userId": "12eadc86-6311-4d5e-8be8-df30799df265"
},
{
"roleName": "user",
"roleId": "a0d5ef46-b1e6-4a53-91ce-9ff5959f1ed8",
"userId": "12eadc86-6311-4d5e-8be8-df30799df265"
},
{
"roleName": "user",
"roleId": "a0d5ef46-b1e6-4a53-91ce-9ff5959f1ed8",
"userId": "3e7cd970-8c52-4dd1-847c-f824671ea15d"
}
]
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