好的,让我们分解一下:
验证用户是否可以写入表(如果为真则返回 1,否则返回 0):
SELECT isnull(has_perms_by_name('MyDb.dbo.MyTable', 'OBJECT', 'INSERT'), 0)
验证用户是否可以编写该发布者:
SELECT count(*) FROM UserPermissions WHERE
UserName = 'username' AND Publisher = 'publisher'
现在,那是那些的 SQL,而不是实际的 C#。在 C# 中获取值:
SqlConnection SqlConn = new SqlConnection("connection_string_goes_here");
SqlCommand SqlCmd = new SqlCommand();
SqlConn.Open();
SqlCmd.Connection = SqlConn;
SqlCmd.CommandText = "SELECT isnull(has_perms_by_name('MyDb.dbo.MyTable', " +
"'OBJECT', 'INSERT'), 0)"
if (SqlCmd.ExecuteScalar())
{
SqlCmd.CommandText =
"SELECT count(*) FROM UserPermissions WHERE " +
"Username = " + System.Environment.UserDomainName + "\" +
System.Environment.UserName + " " +
AND Publisher = @Publisher";
SqlCmd.Parameters.Add("@Publisher", SqlDbType.NVarChar);
SqlCmd.Parameters("@Publisher").Value = PublisherInput;
if(SqlCmd.ExecuteScalar())
{
SqlCmd.Parameters.Clear();
SqlCmd.CommandText = "INSERT INTO Books (Title, Publisher) VALUES " +
"(@Title, @Publisher)";
SqlCmd.Parameters.Add("@Title", SqlDbType.NVarChar);
SqlCmd.Parameters.Add("@Publisher", SqlDbType.NVarChar);
SqlCmd.Parameters("@Title").Value = TitleInput;
SqlCmd.Parameters("@Publisher").Value = PublisherInput;
SqlCmd.ExecuteNonQuery();
}
}
SqlCmd.Dispose();
SqlConn.Close();
SqlConn.Dispose();
最后一点,清理您的输入。在您的应用程序中使用参数,不要信任任何用户,即使是内部用户。我怎么强调都不过分。
编辑:因为给猫剥皮的方法不止一种,我觉得不包括 LINQ to SQL 解决方案是愚蠢的(至少在计数问题上):
int PermsAvailable = (from up in db.UserPermissions
where up.Username ==
System.Environment.UserDomainName + "\" +
System.Environment.UserName
&& up.Publisher == PublisherInput
select up).Count();
if(PermsAvailable)
{
var NewBook = New Book with {.Title = TitleInput, .Publisher = PublisherInput};
db.Books.Add(NewBook);
}