'instance failure' error while connection string is correct - asp.net

I have following code on page load event:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
con = New SqlConnection("Data Source=14GRAFICALI\\SQLEXPRESS;Initial Catalog=sagar;Integrated Security=True")
'-----------------------fill name ddl------------------------------'
Try
da = New SqlDataAdapter("select EmpName from empMaster_VB", con)
ds = New DataSet()
da.Fill(ds)
For i As Integer = 0 To ds.Tables(0).Rows.Count
ddlName.Items.Add(ds.Tables(0).Rows(i)(0).ToString())
Next
Catch ex As Exception
End Try
'--------------------------------------------------------------------'
'----------------fill expence-------------------------------------'
Try
da = New SqlDataAdapter("select ExpName from expenceType_VB", con)
ds = New DataSet()
da.Fill(ds)
For i As Integer = 0 To ds.Tables(0).Rows.Count
ddlExpence.Items.Add(ds.Tables(0).Rows(i)(0).ToString())
Next
Catch ex As Exception
End Try
'---------------------------------------------------------------'
End Sub
This code is to fill drop downs with names and expence values in database tables.
I am getting 'instance failure' error while executing the code.
I checked one of the answers on stack and checked my connection string. But, my connection string is also correct.
Please help me if anything else is missing in this code.

As you got the error "instance failure", that might be the error with your SQL Server instance..
Make sure your SQL Server instance(MSSQLSERVER) is running, where you can check in: Services list. TO get into services list: open run dialog box and type: "services.msc" (without quotes) and hit Enter. That takes you to services management console, where you can check whether your instance in running or not..
If the problem still persists, then try using: Data Source=.\SQLEXPRESS instead.. :)
Happy Coding... :)

I have connection:
Data Source=MyComputerName\SQL2012ENTERPRS;Initial Catalog=RESTFUL; User Id=myuser; Password=mypass123;
My server is : MyComputerName\SQL2012ENTERPRS
But since I use string, I add more \ so, at my code It will be:
public string connectionString = "Data Source=DAFWKN409C67Q\\SQL2012ENTERPRS;Initial Catalog=RESTFUL; User Id=rest_user; Password=rest_pwd_01;";
I have forgoten that I must remove one of \ since I am not use default string block, I use XML file to save my connection string. Then everything is ok. So, my suggestion is your instance name is not correct.
This is my connection string sample it I use local pc using SQL express:
string servername = #"Data Source=.\SQLExpress;Initial Catalog=Workshop;Integrated Security=True";
You should modify with your server name, and instance name by yourself, make sure it correct.

I had this issue because I got the connection string from appsettings.Development.json:
"Server=msi\\DataBaseName;Database=Super25;Trusted_Connection=True;"
but when I changed to
"Data Source=msi\DataBaseName;Initial Catalog=Super25;Integrated Security=True;"
solved!

in my case just kick up the double \\ to one slush \
:=)

The root cause is Regular literal ("Backslash: \") and Verbatim literal ("#"Backslash: \"") .
Reference https://csharpindepth.com/Articles/Strings

Use the wildcard "#" before "Data Source" declaration. someting like this:
connetionString = #"Data Source=...
So you'll be able to use only a back slash. Like this: #"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\jcabarros...

I know this is an old thread, but perhaps a good update. I couldn't find a good answer on the web search.
I got the same 'Instance Failed' error when trying to reference a DbContext from another project in the same solution. The 1st project had a DbContext and the connection string, and the 2nd project in the solution was trying to reference it. The 1st app ran ok on its own, issue only occurred when running the 2nd app.
The issue was that the app.config file that had the connection string from the 1st project was not in view/scope of the 2nd project. So the connection string wasn't assembled.
My solution was to copy the app.config from the first project to the second project.
This was on VS 2019.
Hope this helps

Your answer lies in the connected services. edit provider and select the three dots once you find your database select advanced in the advanced you will see your connection string which looks like below.
Data Source=Server\ServerInstance;Initial Catalog=yourDatabaseName;Integrated Security=True
You can add more services and configure more there.

Related

ASP.NET modify connectionstring at runtime

I need to change dataset connectionstrings to point to different DBs at run time.
I've looked at a number of solutions however they all seem to be related to WinForms or web application projects or other technology slightly different than what I'm using, so I haven't figured out how apply them.
The application is like a discussion. It's a web site project based on code originally written under VS2005, and there's no budget (or personal talent!) for major changes at this time. The app is written in vb.net; I can understand answers in c#. I'm working in VS2013.
The app has three typed datasets pointing to one MDF, call it "MainDB.mdf". There are dozens of tableadapters among the three datasets.
I'm going to deploy the app it as an "alpha/demo" version. I would like to use the same code base for all users, and a separate physical version of MainDB for each user, to reduce chances that the users crash each other.
The initial demo access URL will contain query string information that I can use to connect the user with the right physical database file. I should be able to identify the database name and thus the connection string parameters from the query string information (probably using replace on a generic connection string). If necessary I could use appsettings to store fully formed connection strings, however, I would like to avoid that.
I would like to be able to change the connection strings for all the datasets at the time that the entry point pages for the app are accessed.
Changing the tableadapter connection strings at each instantiation of the tableapters would require too much code change (at least a couple of hundred instantiations); I'd just make complete separate sites instead of doing that. That's the fall back position if I can't dynamically change the connectionstrings at runtime (or learn some other way to make this general scheme work).
Any suggestions on how to approach this would be appreciated.
Thanks!
UPDATE: Per comments, here is a sample instantiation of tableadapter
Public Shared Sub ClearOperCntrlIfHasThisStaff( _
varSesnID As Integer, varWrkprID As Integer)
Dim TA As GSD_DataSetTableAdapters.OPER_CNTRLTableAdapter
Dim DR As GSD_DataSet.OPER_CNTRLRow
DR = DB.GetOperCntrlRowBySesnID(varSesnID)
If IsNothing(DR) Then
Exit Sub
End If
If DR.AField = varWrkprID Then
DR.AField = -1
TA.Update(DR)
DR.AcceptChanges()
End If
End Sub
UPDATE: Below is the test code I tried in a test site to modify the connectionString in a single instantiation of a tableadapter. It feeds a simple gridview. I tried calling this from Page_Load, Page_PreLoad, ObjectDataSource_Init, and Gridview_Databind. At the concluding response.writes, the wrkNewConnString looks changed to TestDB2, and the TA.Connection.ConnectionString value looks changed to TestDB2, but the displayed gridview data is still from TestDB1. Maybe it needs to be called from somewhere else?
Sub ChangeTableAdapter()
Dim wrkNewConnStr As String = ""
Dim wrkSel As Integer
wrkSel = 2
wrkNewConnStr = wrkNewConnStr & "Data Source=.\SQLEXPRESS;"
wrkNewConnStr = wrkNewConnStr & "AttachDbFilename=D:\9000_TestSite\App_Data\TESTDB1.MDF;Integrated Security=True;User Instance=True"
Select Case wrkSel
Case 1
wrkNewConnStr = wrkNewConnStr.Replace("TESTDB1", "TESTDB1")
Case 2
wrkNewConnStr = wrkNewConnStr.Replace("TESTDB1", "TESTDB2")
Case 3
wrkNewConnStr = "Data Source=localhost; Initial Catalog=test01;"
wrkNewConnStr = wrkNewConnStr & " User ID=testuser1; Password=testuserpw1"
End Select
Try
Dim TA As New DataSetTableAdapters.NamesTableAdapter
TA.Connection.ConnectionString = wrkNewConnStr
Response.Write("1 - " & wrkNewConnStr)
Response.Write("<br/>")
Response.Write("2 - " & TA.Connection.ConnectionString)
Catch ex As Exception
Dim exmsg As String = ex.Message
Response.Write(exmsg)
End Try
End Sub
The connection string:
<add name="TestDB1ConnectionString"
connectionString="Data Source=.\SQLEXPRESS;
AttachDbFilename=D:\9000_TestSite\App_Data\TESTDB1.MDF;Integrated Security=True;User Instance=True"
providerName="System.Data.SqlClient" />
UPDATE: the following post has lots of solutions, however, they seem to focus on web application projects, that have a project file with settings, which this web site project does not.
link with possible solutions
UPDATE: this next link was brought to my attention, and in working on it I did get it to work, however, it still relies either on having a web application project (with project file) or modifying each table adapter as they are instantiated. So, while I'm not going to implement it, I believe that is the technical answer.
modifying connection strings
sorry if this answer is too late, but I have exactly the same problem and eventually came up with a solution using Reflection.
My solution was to "save" a new default value for the connection string in the settings at run time, which means any further use of the table adapter uses the the new connection string.
It should be noted the term "save" is misleading as the new value is lost when the application closes.
Have tested and worked perfectly.
public void ChangeDefaultSetting(string name, string value)
{
if (name == null)
throw new ArgumentNullException("name");
if (value == null)
throw new ArgumentNullException("value");
Assembly a = typeof({Put the name of a class in the same assembly as your settings class here}).Assembly;
Type t = a.GetType("{Put the full name of your settings class here}");
PropertyInfo propertyInfo = t.GetProperty("Default");
System.Configuration.ApplicationSettingsBase def = propertyInfo.GetValue(null) as System.Configuration.ApplicationSettingsBase;
//change the "defalt" value and save it to memory
def[name] = value;
def.Save();
}

How to trace a call to a stored procedure and get feedback out of its execution?

I have a stored procedure that I'm calling from asp.net and I'm adding 47 parameters mostly from values selected on drop downs and radio buttons and text boxes from a form. I also have (for some reason beyond my pay grade) some parameters that are set to Null..these are also a source of some hair pulling and I don't know if these are the problems or not.
Dim Parameter As SqlParameter = New SqlParameter("#type", "u")
Dim Parameter1 As SqlParameter = New SqlParameter("#user", User)
Dim Parameter2 As SqlParameter = New SqlParameter("#term", terminal)
Dim Parameter3 As SqlParameter = New SqlParameter("#url", accesslevel)
Dim Parameter4 As SqlParameter = New SqlParameter("#name", firstname & " " & lastname)
Dim Parameter5 As SqlParameter = New SqlParameter("#mgr", mgr)
Dim Parameter6 As SqlParameter = New SqlParameter("#mgrEmail", mgr)
Dim Parameter7 As SqlParameter = New SqlParameter("#phone", mgr)
Dim Parameter8 As SqlParameter = New SqlParameter("#title", titletitle)`
... and on and on until Parameter48...
Dim myCommand As New SqlCommand("dbo.proc_vsSpacAccess", conn)
myCommand.CommandType = CommandType.StoredProcedure
myCommand.Parameters.Add(Parameter)
myCommand.Parameters.Add(Parameter1)
myCommand.Parameters.Add(Parameter2)
myCommand.Parameters.Add(Parameter3)
myCommand.Parameters.Add(Parameter4)
... and on until Parameter48... and then finally I run the stored proc..
myCommand.ExecuteNonQuery()
end of subroutine...
I run this and get nothing, no feedback, nothing. How do I know what's wrong if things aren't working? do I debug from SQL Server (I can't change the stored procedure it's not mine to change btw) or try to debug the stored procedure from Visual Studio?
I REPEAT, I CANNOT CHANGE THE STORED PROCEDURE IT IS READ ONLY FOR ME..
ExecuteNonQuery won't return anything unless you explicitly catch the return value.
If you want to know how query is executing, you can view using SQL Server Profiler.
Set a break point right after ExecuteNonQuery
Let SQL Server Profiler run at the background
See the executed query
You can even copy the query from Profiler, and run it in SSMS to make sure it even works.
Let me give you some advice on debugging. First run profiler when you run your application (on dev!) and grab the SQL that is generated.
Next open up SSMS and put that SQL in it and see if it generated valid sql. Sometimes you qwill find it did not. Then the problem is in how you are building the sql. If the SQL is valid, either it ran but didn't give you a return message or the problem is the proc itself or the data in the parameters.
Then open up the stored proc to see what it does; if it is inserting to a table or updating a table, check that table in the db to see if the data was inserted or updated based on teh variables you sent. You should always have unit tests built to check the results of an action stored proc, if you do not, then write them now, so the next time you test, you know what you should see in the database as a result of running the proc.
If you did not get the action you expected, try running the proc from SSMS with the profiled data. If the data still doesn't insert or update, you may need to ask the people responsible for the proc to track down what the problem is. Likely in this case, soemthing is wrong with the particular parameters you are sending although it could bea genuiine bug of a case taht was not expected. For instance you may be sending a null for a reuired field. Not all procs are built to properly handle errors, so it may not be sending one up the chain to you.
Lets start from the point that when it comes to executing stored procedures, you need to design it to return some feedback. Just the fact that you have stored procedure, doesn't mean that you will have any feedback. For example (pseudo-code)
Create procedure MyProc()
Begin
Try
-- Do something
-- And it happens to error here
Catch
' do nothing
End Try
End
Now, this one, will never give you any info of what happened, success or failure because error is handled within
Lets look at this one now, again, pseudo-code
Create procedure MyProc(#retVal int out)
Begin
set #retVal = -1 -- assume it failed
Try
-- Do something
set #retVal = 0 -- a flag that it is success
Catch
' do nothing
End Try
End
Now, with this you can go to your vb code and test
myCommand.ExecuteNonQuery()
Dim val as Object = myCommand.Parameters(0).Value
If CInt(val) = 0 Then
' success route
Else
' error route
End If
Basically, this is the example of one of the few methods how to obtain info about state of execution of your stored procedure. But again, you need to code for this.
Now, if you want to know in details, what is your SP doing while it is executing, again, you need to code for this. You can create a log table, in which you will store data that you scrape within your SP. I've seen designs where each SP had one parameter #debug. And, when called in debug mode, it would post logs about its execution data.

ASP to SQL Server connection basics?

I apologize in advance if the question is too noobish. I am new to the ASP and SQL server world (i've been using PHP and MySQL up to this point) (I've read other topics here, but none seemed to give me a clear answer)
I want to connect my ASP website to my SQL database (using sql server 2005 currently), how would i do that? I've been trying to use numerous connection strings, but everything seems confusing to me right now (too many varieties)
Also, how do i execute queries after making a succesful connection?
I believe an answer to those two would get me started on, i hope i'm not asking for much or something. Thanks in advance!
Dim objDbCon
Dim dataCount
Dim sqlQuery
Set objDbCon = Server.CreateObject("ADODB.Connection")
'Change the parameters with your own environment'
objDbCon.ConnectionString = "Provider=SQLOLEDB; Data Source=120.120.120.120; Initial Catalog=Database name; User Id=user1; Password=1234;"
objDbCon.Open
'Put sql script which you want to get result set'
sqlQuery = "SELECT COUNT(*) AS CNT FROM TABLE_NAME"
'This is how you execute sql script and bind the result set to dataset object'
Set Rs = objDbCon.Execute(sqlQuery)
dataCount = Rs("CNT")
Rs.Close
To add sql connection to a asp.net webpage, First we have to get the connection string.
For that open server explorer ->Data connections ->add connection.
Give the servername and database name in the given popup box.
After adding the connection take the property window of added connection, From there we will get the connection string.
After that write the following code:
using System.Data;
using System.Data.SqlClient;
public void dbconnection
{
SqlConnection con;
con = new SqlConnection("connectionstring");
con.Open();
SqlCommand cmd=new SqlCommand("Your sql query",con);
cmd.ExecuteNonQuery();
con.close();
}
for insert,update and delete queries we use ExecuteNonQuery().
for select queries we use
SqlDataReader dr = cmd.ExecuteReader();

ADODB.Recordset error '800a0bb9' : Arguments are of the wrong type

Set rsPlanID = Server.CreateObject("ADODB.Recordset")
rsPlanID.CursorLocation = adUseClient
strSQL = "SELECT PlanID FROM ATTJournals WHERE ATTUserDataID = " & ATTUserDataID
rsPlanID.Open strSQL, m_objConn, adOpenStatic, adLockOptimistic
If Not rsPlanID.EOF Then
response.Write "New PlanID:" & rsPlanID("PlanID")
End If
The above code is in classic asp.
I am getting the following error:
ADODB.Recordset error '800a0bb9'
Arguments are of the wrong type, are out of acceptable range, or are in conflict with one another.
Dows anyone know the cause this error and how to fix it?
The most like cause is that you haven't included "ADOVBS.INC" or the equavalent META:-
<!--METADATA
TYPE="TypeLib"
NAME="Microsoft ActiveX Data Objects 2.6 Library"
UUID="{00000206-0000-0010-8000-00AA006D2EA4}"
VERSION="2.6"
-->
Hence the adxxxx constants do not exist. However your primary mistake is not including Option Explicit at the top your script. This will save you bucket loads of time hunting silly mistakes and typos.
BTW What happens if ATTUserDataID contained "0; DELETE ATTJournals;" ?
Avoid composing SQL using concatenation like the plague. Search for "ASP SQL Injection" to find examples of using parameterised command objects instead.
Unless you need to navigate back and forth in the recordset, just use the default settings:
strSQL = "SELECT PlanID FROM ATTJournals WHERE ATTUserDataID = " & ATTUserDataID
Set rsPlanID = m_objConn.Execute(strSQL)
Also, your code is wide open for SQL Injection attacks - you better learn about it and change your code to use Parameters instead.
I feel like I searched the whole internet and couldn't find the solution to this problem, and just as I was about to give up, I realized that I had declared my connection variable within an "If" statement and because the if statement did not execute neither did my command to the database giving the error as mentioned in your question.
First, when I devoleped application with vbscript I used always the numbers to open a recordset. I recommend following line:
rsPlanID.Open strSQL, m_objConn, 3, 3
Make sure that you include the file adovbs.inc first. The numbers are conntected to the different types of recordset properties. And don't foregt to open the databse connection first.
Second, I think you don't need the line
rsPlanID.CursorLocation = adUseClient
Thrird, see also this thread. Maybe it is a good template for you.
Function SQL_getRecordset(strQuery)
'On Error Resume Next
'Create Database connection object
Set objConnection = CreateObject("ADODB.Connection")
'Create Recordset object
Set objrecordset = CreateObject("ADODB.Recordset")
'Specify the connection string
strConnectionstring = "Provider=SQLOLEDB.1;Data Source=*<Server name>*;Initial Catalog=*<database>*;Integrated Security=SSPI"
objConnection.Open strConnectionstring
'Execute the Query
Set objrecordset = objConnection.Execute(strQuery)
'Return Recordset
Set SQL_getRecordset = objrecordset
'Release objects from the memory
Set objConnection = Nothing
Set objrecordset = Nothing
End Function

Local Server Vs. Production Server

Im kinda going a little crazy here. I moved my web application to a server and im getting this error below, but on my localhost it works great. Im kinda at a loss of what i should try. Any help would be very much appreciated. Im finding that the error has to have something to do with the dataset not pulling back any data, when I do a for each statement. But the weird thing is that I do a for each statement on another page and it works fine. Here is my for each statement, that im assuming doesnt work. The reason im assuming it b/c when i test it on local it works fine:
Dim retObj As New ClassLibrary1.sql_class
For Each row As DataRow In retObj.sel_all_email_list(company).tables(0).rows
email += row("EMAIL_ADDRESS") & "/"
Next
'*****************************
sql_class
query = "SELECT * " _
& " FROM EMAIL_LIST " _
& " WHERE UCASE(COMPANY) = '" & company & "'"
Dim adapter As New OleDbDataAdapter(query, myConnection)
Dim ds As New DataSet
Try
myConnection.Open()
adapter2.Fill(ds, "test_table")
*returns the dataset, didnt want to type all of the code
Catch ex As Exception
Finally
myConnection.Close()
End Try
'*****************************************************
Error:
Exception Details: System.IndexOutOfRangeException: Cannot find table 0.
Check the SQL DB running in Production.
The SQL statement used to fill the Dataset isn't returning any data. That leads to the Dataset not having any tables.
As a result when you make your call to Dataset.Tables(0) a System.IndexOutOfRangeException gets thrown (as there are no tables in the Tables collection).
You can mitigate against this by calling Dataset.Tables.Count to ensure it has items before attempting to access the collection.
If retObj.sel_all_email_list(company).tables.count > 0 Then
'Do something
End If

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