我正在使用SQL Server 2012和Linq-to-SQL。
我有这个方法,可以在检查一些条件后更新数据库中的一行。
我用两种方式编写了它。哪一个更快,占用资源更少?(SQL查询、CPU数量...)
查询 #1:
在这个查询中,我使用了 IEnumerable
internal static bool CheckSecretCodeLoginkError(String License, String SecretCode, DataClasses1DataContext db)
{
IEnumerable<User> user = db.Users.Where(a => a.Licensekey == License).Select(a => a);
if (SecretCode != user.First().SecretCode && !user.First().SkipSecretCode)
{
if (user.First().LastSecretChangeDate > DateTime.UtcNow - TimeToPreventSecretCodeChange)
{
//secret error
return true;
}
else
{
//no error
//update secret code and last change
user.First().LastSecretChangeDate = DateTime.UtcNow;
user.First().SecretCode = SecretCode;
db.SubmitChanges();
return false;
}
}
else
{
return false;
}
}
查询2:
internal static bool CheckSecretCodeLoginkError(String License, String SecretCode, DataClasses1DataContext db)
{
User user = db.Users.Where(a => a.Licensekey == License).Single();
if (SecretCode != user.SecretCode && !user.SkipSecretCode)
{
if (user.LastSecretChangeDate > DateTime.UtcNow - TimeToPreventSecretCodeChange)
{
//secret error
return true;
}
else
{
//no error
//update secret code and last change
db.Users.Where(a => a.Licensekey == License).Select(a => a).First().LastSecretChangeDate = DateTime.UtcNow;
db.Users.Where(a => a.Licensekey == License).Select(a => a).First().SecretCode = SecretCode;
db.SubmitChanges();
return false;
}
}
else
{
return false;
}
}