public static void Show()
{
///一次SaveChanges 多个数据操作都生效了
///事务
//using (EFCoreMigrationContext context = new EFCoreMigrationContext())
//{
// SysUserInfo sysUserInfo1 = context.SysUserInfo.FirstOrDefault(a => a.Id == 6);
// SysUserInfo sysUserInfo2 = context.Set<SysUserInfo>().Find(5);
// sysUserInfo1.Name += "-AA";
// sysUserInfo2.Name += "-BB";
// context.SaveChanges();
//}
///DbContext SaveChanges 事务提交 事务提交
///事务特点：要不都成功 要么都知道
//using (EFCoreMigrationContext context = new EFCoreMigrationContext())
//{
// SysLog log = context.SysLog.FirstOrDefault(l => l.Id == 1);
// context.SysLog.Remove(log);
// SysUserInfo sysUserInfo1 = context.SysUserInfo.FirstOrDefault(a => a.Id == 6);
// SysUserInfo sysUserInfo2 = context.Set<SysUserInfo>().Find(5);
// sysUserInfo1.Name += "-AA";
// sysUserInfo2.Name += "-BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
// context.SysLog.Add(new SysLog()
// {
// UserName = "******",
// Introduction="描述一下"
// });
// context.SaveChanges();
//}
//1.单例 DbContext 整个进程中就只有一个实例 不行；
//2.多线程中 是不是可以使用同一个DbContext 实例？ 一般情况下不要使用同一个实例；除非（特定业务下）
//一个请求一个DbContext实例！
#region 扩展SaveChanges
{
//using (EFCoreMigrationContext context = new EFCoreMigrationContext())
//{
// context.SysLog.Add(new SysLog()
// {
// UserName = "******",
// Introduction = "描述一下",
// CreateTime = DateTime.Now
// });
// context.SaveChanges();
// SysLog log = context.SysLog.OrderByDescending(a => a.Id).FirstOrDefault();
// log.UserName = "******";
// //log.LastModifyTime = DateTime.Now;
// //log.CreateTime
// //每修改一次都需要重新设置值
// ///能不能从框架层面扩展后来自动维护呢？
// context.SaveChanges();
//}
}
#endregion
{
/////如果我需要把两个SaveChange 事务一下的？
using (EFCoreMigrationContext context = new EFCoreMigrationContext())
{
IDbContextTransaction tans = null;
try
{
tans = context.Database.BeginTransaction(); //框架对事务的支持
context.SysLog.Add(new SysLog()
{
UserName = "******",
Introduction = "第一次SaveChanges",
CreateTime = DateTime.Now
});
context.SaveChanges();
context.SysLog.Add(new SysLog()
{
UserName = "******",
Introduction = "第二次SaveChanges",
CreateTime = DateTime.Now
});
context.SaveChanges();
tans.Commit(); //代码只有执行到这里事务才能生效
}
catch (Exception ex)
{
if (tans != null)
{
tans.Rollback();//事务回退
}
Console.WriteLine(ex.Message);
}
finally
{
tans.Dispose();
}
}
}
//{
// ///如果我需要把两个SaveChange 事务一下的？
// using (EFCoreMigrationContext context1 = new EFCoreMigrationContext()) //招商银行的数据库
// using (EFCoreMigrationContext context2 = new EFCoreMigrationContext())////腾讯平台的数据库
// {
// //需要引入System.Transactions.Local.dll
// using (TransactionScope transactionScope = new TransactionScope())
// {
// try
// {
// context1.SysLog.Add(new SysLog()
// {
// UserName = "******",
// Introduction = "context1新增一条测试数据",
// CreateTime = DateTime.Now
// });
// context1.SaveChanges();
// context2.SysLog.Add(new SysLog()
// {
// UserName = "******",
// Introduction = "context2新增一条测试数据",
// CreateTime = DateTime.Now
// });
// context2.SaveChanges();
// transactionScope.Complete();//提交事务
// }
// catch (Exception ex)
// {
// Console.WriteLine(ex.Message);
// }
// }
// }
//}
}
public static void Show()
{
#region 其他查询
using (EFCoreMigrationContext dbContext = new EFCoreMigrationContext())
{
{
var list = dbContext.SysUserInfo.Where(u => 1 == 1 && !(new int[] { 1, 2, 3, 5, 7, 8, 9, 10, 11, 12, 14, 17 }.Contains(u.Id)));//in查询
foreach (var user in list)
{
System.Console.WriteLine(user.Name);
}
}
{
var list = from u in dbContext.SysUserInfo
where new int[] { 1, 2, 3, 5, 7, 8, 9, 10, 11, 12, 14, 17 }.Contains(u.Id)
select u;
foreach (var user in list)
{
System.Console.WriteLine(user.Name);
}
}
{
var list = dbContext.SysUserInfo.Where(u => new int[] { 1, 2, 3, 5, 7, 8, 9, 10, 11, 12, 14, 17 }.Contains(u.Id))
.OrderBy(u => u.Id)
.Select(u => new
{
Name = u.Name,
Pwd = u.Password
}).Skip(3).Take(5);
foreach (var user in list)
{
System.Console.WriteLine(user.Name);
}
}
{
var list = dbContext.SysUserInfo.Where(u => u.Name.StartsWith("Richard") && u.Name.EndsWith("老师"))
.Where(u => u.Name.EndsWith("老师"))
.Where(u => u.Name.Contains("Richard"))
.Where(u => u.Name.Length < 10)
.OrderBy(u => u.Id);
foreach (var user in list)
{
System.Console.WriteLine(user.Name);
}
}
{
var list = from u in dbContext.SysUserInfo
join c in dbContext.SysUserRoleMapping on u.Id equals c.SysUserId
where new int[] { 1, 2, 3, 5, 7, 8, 9, 10, 11, 12, 14, 17 }.Contains(u.Id)
select new
{
Name = u.Name,
Pwd = u.Password,
RoleId = c.SysRoleId
};
foreach (var user in list)
{
System.Console.WriteLine("{0} {1}", user.Name, user.Pwd);
}
}
{
var list = from u in dbContext.SysUserInfo
join m in dbContext.SysUserRoleMapping on u.Id equals m.SysUserId
join r in dbContext.SysRole on m.SysRoleId equals r.Id
where new int[] { 1, 2, 3, 5, 7, 8, 9, 10, 11, 12, 14, 17 }.Contains(u.Id)
select new
{
Name = u.Name,
Pwd = u.Password,
RoleId = m.SysRoleId,
RoleName = r.Name
};
foreach (var user in list)
{
System.Console.WriteLine("{0} {1} {2}", user.Name, user.Pwd, user.RoleName);
}
}
}
using (EFCoreMigrationContext dbContext = new EFCoreMigrationContext())
{
{
try
{
string sql = "Update Zhaxoxi.SysUser Set UserName='******' WHERE Id=@Id";
SqlParameter parameter = new SqlParameter("@Id", 1);
dbContext.Database.ExecuteSqlRaw(sql, parameter);
}
catch (Exception ex)
{
throw ex;
}
}
}
//using (EFCoreMigrationContext dbContext = new EFCoreMigrationContext())
//{
// {
// DbContextTransaction trans = null;
// try
// {
// trans = dbContext.Database.BeginTransaction();
// string sql = "Update [SysUserInfo] Set Name='王一-小王子' WHERE Id=@Id";
// SqlParameter parameter = new SqlParameter("@Id", 10);
// dbContext.Database.ExecuteSqlCommand(sql, parameter);
// trans.Commit();
// }
// catch (Exception ex)
// {
// if (trans != null)
// trans.Rollback();
// throw ex;
// }
// finally
// {
// trans.Dispose();
// }
// }
// {
// DbContextTransaction trans = null;
// try
// {
// trans = dbContext.Database.BeginTransaction();
// string sql = "SELECT * FROM [SysUserInfo] WHERE Id=@Id";
// SqlParameter parameter = new SqlParameter("@Id", 1);
// List<SysUserInfo> userList = dbContext.Database.SqlQuery<SysUserInfo>(sql, parameter).ToList();
// trans.Commit();
// }
// catch (Exception ex)
// {
// if (trans != null)
// trans.Rollback();
// throw ex;
// }
// finally
// {
// trans.Dispose();
// }
// }
//}
#endregion
}
