我有一个日志查看应用程序，它将日志语句写入数据库，然后将它们从数据库发送到日志查看器 GUI。我希望能够打开多个日志查看器实例，但是当我这样做时，它将创建一个与查看器的前一个实例同名的数据库。如果已经创建了一个数据库，我尝试创建一个具有不同名称的数据库，但这似乎不起作用。有什么建议么？这是创建/访问/销毁数据库的代码：
public class Database
{
public bool hasAdminPriv
{
get;
set;
}
public bool hasBeenCreated
{
get;
set;
}
public Database()
{
hasAdminPriv = true;
//Construction checks to see if user has Admin priveleges
bool isElevated;
WindowsIdentity identity = WindowsIdentity.GetCurrent();
WindowsPrincipal principal = new WindowsPrincipal(identity);
isElevated = principal.IsInRole(WindowsBuiltInRole.Administrator);
if (!isElevated)
hasAdminPriv = false;
}
//returns true if the database creation was successful
public bool CreateDatabase()//creates a database dynamically by making a query request to the server
{
String str;
SqlConnection myConn = new SqlConnection("Data Source=" + Environment.UserName + "-D1SD\\SQLEXPRESS; Initial Catalog=Master;Integrated Security=True");
str = "CREATE DATABASE MyDatabase ON PRIMARY " +
"(NAME = MyDatabase_Data, " +
"FILENAME = 'C:\\Program Files (x86)\\Microsoft SQL Server\\MSSQL.1\\MSSQL\\Data\\MyDatabaseData.mdf', " +
"SIZE = 30MB, MAXSIZE = 10GB, FILEGROWTH = 20%) " +
"LOG ON (NAME = MyDatabase_Log, " +
"FILENAME = 'C:\\Program Files (x86)\\Microsoft SQL Server\\MSSQL.1\\MSSQL\\Data\\MyDatabaseLog.ldf', " +
"SIZE = 10MB, " +
"MAXSIZE = 1GB, " +
"FILEGROWTH = 10%)";
SqlCommand myCommand = new SqlCommand(str, myConn);
try
{
myConn.Open();
myCommand.ExecuteNonQuery();
}
catch (System.Exception ex)
{
int done = 0;
while (done < 10)
{
String str2 = "CREATE DATABASE" + done + " MyDatabase ON PRIMARY " +
"(NAME = MyDatabase_Data, " +
"FILENAME = 'C:\\Program Files (x86)\\Microsoft SQL Server\\MSSQL.1\\MSSQL\\Data\\MyDatabaseData.mdf', " +
"SIZE = 30MB, MAXSIZE = 10GB, FILEGROWTH = 20%) " +
"LOG ON (NAME = MyDatabase_Log, " +
"FILENAME = 'C:\\Program Files (x86)\\Microsoft SQL Server\\MSSQL.1\\MSSQL\\Data\\MyDatabaseLog.ldf', " +
"SIZE = 10MB, " +
"MAXSIZE = 1GB, " +
"FILEGROWTH = 10%)";
SqlCommand myCommand2 = new SqlCommand(str2, myConn);
try{
myCommand2.ExecuteNonQuery();
}
catch{
++done;
}
myConn.Close();
hasBeenCreated = true;
return true;
}
return false;
}
finally
{
if (myConn.State == ConnectionState.Open)
{
myConn.Close();
}
}
hasBeenCreated = true;
return true;
}
//Creates the table in the database by a query request
//a return value of true means Database was created succesfully
public bool CreateTable()
{
SqlConnection myConn = new SqlConnection("Data Source=" + Environment.UserName + "-D1SD\\SQLEXPRESS; Initial Catalog=MyDatabase;Integrated Security=True");
string createString = "CREATE TABLE storage (ID INT NOT NULL, Level varchar(255) , LevelInt INT, DateTime varchar(255),Counter smallint,Device varchar(255), Source varchar(255), Description varchar(255),PRIMARY KEY (ID))"; //YOUR SQL COMMAND TO CREATE A TABLE
SqlCommand create = new SqlCommand(createString, myConn);
myConn.Open();
create.ExecuteNonQuery();
myConn.Close();
return true;
}
//Add the element's values to the database/table to later recall/reorder
public bool addElement(LogParse log,int num)
{
SqlConnection con = new SqlConnection("Data Source=" + Environment.UserName + "-D1SD\\SQLEXPRESS;Initial Catalog=MyDatabase;Integrated Security=True");
try
{
con.Open();
SqlCommand cmd = new SqlCommand("Insert into storage(ID, Level, LevelInt, DateTime, Counter, Device, Source, Description) values(" + num + ",@Level, @LevelInt, @DataTimeItem,@counterItem,@deviceItem,@sourceItem,@descItem)", con);
cmd.Parameters.AddWithValue("@Level", log.Level);
cmd.Parameters.AddWithValue("@LevelInt", log.LevelInt);
cmd.Parameters.AddWithValue("@DataTimeItem", log.TimeStamp);
cmd.Parameters.AddWithValue("@counterItem", log.SequentialNumber);
cmd.Parameters.AddWithValue("@deviceItem", log.Device);
cmd.Parameters.AddWithValue("@sourceItem", log.Source);
cmd.Parameters.AddWithValue("@descItem", log.Description);
cmd.ExecuteNonQuery();
con.Close();
}
catch (Exception ee)
{
return false;
}
return true;
}
//outputs a string array with all the values in the database
public LogParse[] readValue(int start, int end)
{
SqlConnection con = new SqlConnection("Data Source=" + Environment.UserName + "-D1SD\\SQLEXPRESS;Initial Catalog=MyDatabase;Integrated Security=True");
con.Open();
LogParse[] s = new LogParse[end - start];
try
{
using (var oCommand = new SqlCommand("SELECT * From storage WHERE ID BETWEEN @Start AND @End", con))
{
oCommand.Parameters.AddWithValue("@Start", start);
oCommand.Parameters.AddWithValue("@End", end);
using (var oReader = oCommand.ExecuteReader())
{
int i = 0;
while (oReader.Read() && i < end-start)
{
//s[i] = oReader.GetString(1) + oReader.GetString(2) + oReader.GetString(3);
String Level = oReader.GetString(1);
Int32 LevelInt = oReader.GetInt32(2);
String Datetime = oReader.GetString(3);
Int16 SequentialNumber = (Int16)oReader.GetValue(4);
String Device = oReader.GetString(5);
String Source = oReader.GetString(6);
String Description = oReader.GetString(7);
s[i] = new LogParse();
s[i].Level = Level;
s[i].LevelInt = LevelInt;
s[i].TimeStamp = DateTime.Parse(Datetime);
s[i].SequentialNumber = SequentialNumber;
s[i].Device = Device;
s[i].Description = Description;
s[i].Source = Source;
++i;
}
}
}
}
catch
{
}
con.Close();
return s;
}
//Deletes the database by a query statement
//a return value of true means the delete was succesful
public static bool deleteDatabase()
{
String str;
SqlConnection myConn = new SqlConnection("Data Source=" + Environment.UserName + "-D1SD\\SQLEXPRESS; Initial Catalog=Master;Integrated Security=True");
str = @"ALTER DATABASE MyDatabase SET SINGLE_USER WITH ROLLBACK IMMEDIATE;DROP DATABASE [MyDatabase]";
SqlCommand myCommand = new SqlCommand(str, myConn);
try
{
myConn.Open();
myCommand.ExecuteNonQuery();
}
catch (System.Exception ex)
{
return false;
}
finally
{
if (myConn.State == ConnectionState.Open)
{
myConn.Close();
}
}
return true;
}
}