validation - Attempting to validate username (email address) and password - having issues - vb.net -

i have windows form app not validating user input information. need help. inserted microsoft login form , writing code verify user credentials. using access db store , retrieve info. 2 tables - 1 email address , password.
verify format of email addy using regex. works well. validate email address in correct form , verify in table (this works well). attempt read password (appears not working expected) , read both bits of information tables. next, test make sure both present. if both present control passed form.

my issue reading/verifying password.

here visual studio vb.net code.

private sub ok_click(sender system.object, e system.eventargs) handles ok.click      try          if msgbox("is information correct?", msgboxstyle.yesno, "m&p records") = msgboxresult.yes              dim pattern string = "^[a-z][a-z|0-9|]*[a-z][a-z|0-9|]*([_][a-z|0-9]+)*([.][a-z|0-9]+([_][a-z|0-9]+)*)?@[a-z][a-z|0-9|]*\.([a-z][a-z|0-9]*(\.[a-z][a-z|0-9]*)?)$"              dim match system.text.regularexpressions.match = regex.match(txtusername.text.trim(), pattern, regexoptions.ignorecase)             if (match.success)                   try                     if = 0                         provider = "provider=microsoft.ace.oledb.12.0;data source ="                          'change following access database location                         datafile = "\11_2017_spring\csci-2999_capstone\db_m&precords.accdb"                          connstring = provider & datafile                         myconnection.connectionstring = connstring                         myconnection.open()                         = 1                     end if                  catch ex exception                     '  error occured!  show error user , exit.                     messagebox.show(ex.message)                 end try                   'the query:                  dim cmd oledbcommand = new oledbcommand("select * [emailaddress] [emailaddress] = '" & txtusername.text & "'", myconnection)                 dim com oledbcommand = new oledbcommand("select * [password] [password] = '" & txtpassword.text & "'", myconnection2)                  dim dr oledbdatareader = cmd.executereader()                 dim drp oledbdatareader = com.executereader()                  ' following variable hold true if emailaddress found, , false if emailaddress not found                  dim userfound boolean = false                  ' following variable hold true if password found, , false if password not found                  dim passwordfound boolean = false                  ' following variables hold emailaddress , password if found.                 dim emailaddresstext string = ""                 dim passwordtext string = ""                  'if found:                 while dr.read()                     userfound = true                     emailaddresstext = dr("emailaddress").tostring                 end while                  while drp.read()                     passwordfound = true                     passwordtext = drp("password").tostring                 end while                  'checking result                 if userfound = true , passwordfound = true                     frmmain.show()                     frmmain.label1.text = "welcome " & emailaddresstext & " "                 else                     msgbox("sorry, username or password not found", msgboxstyle.okonly, "m&p records - invalid login")                      txtpassword                         .clear()                     end                      txtusername                         .clear()                         .focus()                     end                  end if              else                 messagebox.show("please enter valid email address", "m&p records - email check")                  txtpassword                     .clear()                 end                  txtusername                     .clear()                     .focus()                 end             end if          end if      catch ex exception         '  error occured!  show error user , exit.         messagebox.show(ex.message)     end try  end sub 

well first approach isn't safe due fact the password isn't encrypted , either there no link between email , password ideally have table example:

user --uid --email

pass --id --uid --pass

and hash password example sha512 furthermore more security use salt , certificates secure database connection.

then do: hash current password in textbox , execute:

"select user.email user,pass user.email='textbox_email' , user.uid = pass.uid" 

check if have result if yes connected.

however tried correct bit did in above code. having used sqlclient , not olecommand tried keep did there might few syntax errors should ok:

try     if msgbox("is information correct?", msgboxstyle.yesno, "m&p records") = msgboxresult.yes         dim pattern string = "^[a-z][a-z|0-9|]*[a-z][a-z|0-9|]*([_][a-z|0-9]+)*([.][a-z|0-9]+([_][a-z|0-9]+)*)?@[a-z][a-z|0-9|]*\.([a-z][a-z|0-9]*(\.[a-z][a-z|0-9]*)?)$"         dim match system.text.regularexpressions.match = regex.match(txtusername.text.trim(), pattern, regexoptions.ignorecase)         if (match.success)             dim passwordfound boolean             dim userfound boolean             using con new sqlclient.sqlconnection("provider=microsoft.ace.oledb.12.0;data source =\ 11_2017_spring\csci-2999_capstone\db_m&precords.accdb")                 'using make sure connection disposed                 'open connection                 con.open()                 'prepare sql                 dim command new oledbcommand("select [emailaddress] [emailaddress] [emailaddress] = '" & txtusername.text & "';", con)                 'create reader                 dim reader oledbdatareader = command.executereader()                 dim id string = ""                 ' call read before accessing data.                 while reader.read()                     'get data                     id = reader(0)                 end while                 'close reader                 reader.close()                 if id <> ""                     'user found                     userfound = true                     'prepare second sql                      dim command2 new oledbcommand("select [password] [password] [password] = '" & txtpassword.text & "';", con)                     'prepare second reader                     dim reader2 oledbdatareader = command.executereader()                     dim pass string = ""                     ' call read before accessing data.                     while reader2.read()                         'get tdata                         pass = reader2(0)                     end while                     reader.close()                     if pass <> ""                         'pass found                         passwordfound = true                     else                         passwordfound = false                     end if                 else                     userfound = false                 end if                 'close connection                 con.close()                 'clear connection pool                 sqlconnection.clearpool(con)             end using             'checking result             if userfound = true , passwordfound = true                 frmmain.show()                 frmmain.label1.text = "welcome " & emailaddresstext & " "             else                 msgbox("sorry, username or password not found", msgboxstyle.okonly, "m&p records - invalid login")                 txtpassword                     .clear()                 end                 txtusername                     .clear()                     .focus()                 end             end if         else             messagebox.show("please enter valid email address", "m&p records - email check")             txtpassword                 .clear()             end             txtusername                 .clear()                 .focus()             end         end if     end if catch ex exception     '  error occured!  show error user , exit.     messagebox.show(ex.message) end try