Asp.net - inserting form data into a database

Here is a quick explanation for taking the information from a form throwing it into a database.

First let's import the libraries for connecting to SQL. These need to got at the very top of your code page.

Imports System.Data
Imports System.Data.SqlClient

Now the code. This will likely be placed in the click even of a button.

Dim sqlCon As New SqlConnection("Data Source=.\Sqlexpress;Initial Catalog=Sprinklers;Integrated Security=True")

Dim sql As String = "Insert into Sprinklers " & _
        " (sprinklername,description) " & _
        " values " & _
        " (@sprinklername, @description) "

Dim sqlCommand As New SqlCommand(sql, sqlCon)
sqlCommand.Parameters.Add(New SqlParameter("@sprinklername", SqlDbType.VarChar, 50))
sqlCommand.Parameters("@sprinklername").Value = txtName.Text
sqlCommand.Parameters.Add(New SqlParameter("@description", SqlDbType.VarChar, 500))
sqlCommand.Parameters("@description").Value = txtDesc.Text
sqlCommand.Connection.Open()
Try
sqlCommand.ExecuteNonQuery()
Catch ex As SqlException
MsgBox(ex.Message)
End Try

sqlCommand.Connection.Close()
sqlCommand = Nothing
sqlcon = Nothing

Now for the code with comments. This will explain line by line what is happening.

     ' We need to tell our program how to get to the database
   Dim sqlCon As New SqlConnection("Data Source=.\Sqlexpress;Initial Catalog=Sprinklers;Integrated Security=True")

   ' Here is the statement that inserts data into the database.
   ' Notice the @sprinklername type variable. We will use a parameters
   '  feature to replace those with our form values
   Dim sql As String = "Insert into Sprinklers " & _
             " (sprinklername,description) " & _
             " values " & _
             " (@sprinklername, @description) "

   ' The sql connection told our program where to go, 
   ' this tells the program what to do when it gets there
   ' We are passing in the sql statement and the connection we created before
   Dim sqlCommand As New SqlCommand(sql, sqlCon)

   ' Now its time to give some values to those @ variables
   ' First let's tell the program which param we are dealing with, @sprinklername in this case
   ' The sqldbtype and the last number in the variables here need to match the datatype
   ' and length that are set for the column we are inserting into.
   sqlCommand.Parameters.Add(New SqlParameter("@sprinklername", SqlDbType.VarChar, 50))
   ' Now that we've added a new parameter, let's give it a value.
   sqlCommand.Parameters("@sprinklername").Value = txtName.Text

   ' Do it again for the other variable
   sqlCommand.Parameters.Add(New SqlParameter("@description", SqlDbType.VarChar, 500))
   sqlCommand.Parameters("@description").Value = txtDesc.Text

   ' Our statement is fully prepared and we need to open the connection.
   sqlCommand.Connection.Open()

   Try
     ' This will do the actual execution of the query. We want this inside of
     ' a try in case something goes wrong.
     sqlCommand.ExecuteNonQuery()
   Catch ex As SqlException
     MsgBox(ex.Message)
   End Try

   ' Close the connection to the database
   sqlCommand.Connection.Close()

   ' Do away with the connection and command for memory management.
   sqlCommand = Nothing
   sqlCon = Nothing

Transferring users from one sql server to another

While setting up another server, I set about to learn how to transfer all of my students from one sql server to the new one. I came across this helpful article at: http://support.microsoft.com/kb/918992


To transfer the logins and the passwords from the instance of SQL Server on server A to the instance of SQL Server on server B, follow these steps:

1. On server A, start SQL Server Management Studio, and then connect to the instance of SQL Server from which you moved the database.
2. Open a new Query Editor window, and then run the following script.
   

    USE master 
   GO 
   IF OBJECT_ID ('sp_hexadecimal') IS NOT NULL 
    DROP PROCEDURE sp_hexadecimal 
   GO 
   CREATE PROCEDURE sp_hexadecimal 
     @binvalue varbinary(256), 
     @hexvalue varchar (514) OUTPUT 
   AS 
   DECLARE @charvalue varchar (514) 
   DECLARE @i int 
   DECLARE @length int 
   DECLARE @hexstring char(16) 
   SELECT @charvalue = '0x' 
   SELECT @i = 1 
   SELECT @length = DATALENGTH (@binvalue) 
   SELECT @hexstring = '0123456789ABCDEF' 
   WHILE (@i <= @length) 
   BEGIN 
    DECLARE @tempint int 
    DECLARE @firstint int 
    DECLARE @secondint int 
    SELECT @tempint = CONVERT(int, SUBSTRING(@binvalue,@i,1)) 
    SELECT @firstint = FLOOR(@tempint/16) 
    SELECT @secondint = @tempint - (@firstint*16) 
    SELECT @charvalue = @charvalue + 
     SUBSTRING(@hexstring, @firstint+1, 1) + 
     SUBSTRING(@hexstring, @secondint+1, 1) 
    SELECT @i = @i + 1 
   END 
    
   SELECT @hexvalue = @charvalue 
   GO 
     
   IF OBJECT_ID ('sp_help_revlogin') IS NOT NULL 
    DROP PROCEDURE sp_help_revlogin 
   GO 
   CREATE PROCEDURE sp_help_revlogin @login_name sysname = NULL AS 
   DECLARE @name sysname 
   DECLARE @type varchar (1) 
   DECLARE @hasaccess int 
   DECLARE @denylogin int 
   DECLARE @is_disabled int 
   DECLARE @PWD_varbinary varbinary (256) 
   DECLARE @PWD_string varchar (514) 
   DECLARE @SID_varbinary varbinary (85) 
   DECLARE @SID_string varchar (514) 
   DECLARE @tmpstr varchar (1024) 
   DECLARE @is_policy_checked varchar (3) 
   DECLARE @is_expiration_checked varchar (3) 
    
   DECLARE @defaultdb sysname 
     
   IF (@login_name IS NULL) 
    DECLARE login_curs CURSOR FOR 
    
      SELECT p.sid, p.name, p.type, p.is_disabled, p.default_database_name, l.hasaccess, l.denylogin FROM  
   sys.server_principals p LEFT JOIN sys.syslogins l 
      ON ( l.name = p.name ) WHERE p.type IN ( 'S', 'G', 'U' ) AND p.name <> 'sa' 
   ELSE 
    DECLARE login_curs CURSOR FOR 
    
    
      SELECT p.sid, p.name, p.type, p.is_disabled, p.default_database_name, l.hasaccess, l.denylogin FROM  
   sys.server_principals p LEFT JOIN sys.syslogins l 
      ON ( l.name = p.name ) WHERE p.type IN ( 'S', 'G', 'U' ) AND p.name = @login_name 
   OPEN login_curs 
    
   FETCH NEXT FROM login_curs INTO @SID_varbinary, @name, @type, @is_disabled, @defaultdb, @hasaccess, @denylogin 
   IF (@@fetch_status = -1) 
   BEGIN 
    PRINT 'No login(s) found.' 
    CLOSE login_curs 
    DEALLOCATE login_curs 
    RETURN -1 
   END 
   SET @tmpstr = '/* sp_help_revlogin script ' 
   PRINT @tmpstr 
   SET @tmpstr = '** Generated ' + CONVERT (varchar, GETDATE()) + ' on ' + @@SERVERNAME + ' */' 
   PRINT @tmpstr 
   PRINT '' 
   WHILE (@@fetch_status <> -1) 
   BEGIN 
    IF (@@fetch_status <> -2) 
    BEGIN 
     PRINT '' 
     SET @tmpstr = '-- Login: ' + @name 
     PRINT @tmpstr 
     IF (@type IN ( 'G', 'U')) 
     BEGIN -- NT authenticated account/group 
    
      SET @tmpstr = 'CREATE LOGIN ' + QUOTENAME( @name ) + ' FROM WINDOWS WITH DEFAULT_DATABASE = [' + @defaultdb + ']' 
     END 
     ELSE BEGIN -- SQL Server authentication 
       -- obtain password and sid 
         SET @PWD_varbinary = CAST( LOGINPROPERTY( @name, 'PasswordHash' ) AS varbinary (256) ) 
       EXEC sp_hexadecimal @PWD_varbinary, @PWD_string OUT 
       EXEC sp_hexadecimal @SID_varbinary,@SID_string OUT 
     
       -- obtain password policy state 
       SELECT @is_policy_checked = CASE is_policy_checked WHEN 1 THEN 'ON' WHEN 0 THEN 'OFF' ELSE NULL END FROM sys.sql_logins WHERE name = @name 
       SELECT @is_expiration_checked = CASE is_expiration_checked WHEN 1 THEN 'ON' WHEN 0 THEN 'OFF' ELSE NULL END FROM sys.sql_logins WHERE name = @name 
     
         SET @tmpstr = 'CREATE LOGIN ' + QUOTENAME( @name ) + ' WITH PASSWORD = ' + @PWD_string + ' HASHED, SID = ' + @SID_string + ', DEFAULT_DATABASE = [' + @defaultdb + ']' 
    
       IF ( @is_policy_checked IS NOT NULL ) 
       BEGIN 
        SET @tmpstr = @tmpstr + ', CHECK_POLICY = ' + @is_policy_checked 
       END 
       IF ( @is_expiration_checked IS NOT NULL ) 
       BEGIN 
        SET @tmpstr = @tmpstr + ', CHECK_EXPIRATION = ' + @is_expiration_checked 
       END 
     END 
     IF (@denylogin = 1) 
     BEGIN -- login is denied access 
      SET @tmpstr = @tmpstr + '; DENY CONNECT SQL TO ' + QUOTENAME( @name ) 
     END 
     ELSE IF (@hasaccess = 0) 
     BEGIN -- login exists but does not have access 
      SET @tmpstr = @tmpstr + '; REVOKE CONNECT SQL TO ' + QUOTENAME( @name ) 
     END 
     IF (@is_disabled = 1) 
     BEGIN -- login is disabled 
      SET @tmpstr = @tmpstr + '; ALTER LOGIN ' + QUOTENAME( @name ) + ' DISABLE' 
     END 
     PRINT @tmpstr 
    END 
    
    FETCH NEXT FROM login_curs INTO @SID_varbinary, @name, @type, @is_disabled, @defaultdb, @hasaccess, @denylogin 
     END 
   CLOSE login_curs 
   DEALLOCATE login_curs 
   RETURN 0 
   GO

   
   Note This script creates two stored procedures in the master database. The two stored procedures are named the sp_hexadecimal stored procedure and the sp_help_revlogin stored procedure.
3. Run the following statement.

   EXEC sp_help_revlogin

   The output script that is generated by the sp_help_revlogin stored procedure is the login script. This login script creates the logins that have the original Security Identifier (SID) and the original password.
4. On server B, start SQL Server Management Studio, and then connect to the instance of SQL Server to which you moved the database.
   
   Important Before you go to step 5, review the information in the "Remarks" section.
5. Open a new Query Editor window, and then run the output script that is generated in step 3.