CODEWITHSUNDEEP
c#databaseconnection-string
Markus
Markus

Reputation: 133

Extracting connection string from configuration manager

I have a problem. I am trying To extract a connection string through 

sqlConnStr = new qlConnection(ConfigurationManager.ConnectionStrings["PlacementConnectionString"].ConnectionString);

but it keeps failing :

Object Ref not set to an instance of an object

I check with the debugger and this is the value of the connectionStr

{Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\Placement.accdb}

I have imported my database through VS2012's DataSet wizard so what am I doing wrong?

PS: I have tested the connection numerous times.

<connectionStrings>
   <add name="_201103578_P09.Properties.Settings.PlacementConnectionString" 
        connectionString="Provider=Microsoft.ACE.OLEDB.12.0;DataSource=|DataDirectory|\Placement.accdb"
        providerName="System.Data.OleDb" />
</connectionStrings>

Kind regards

Markus

[UPDATE]

I changed from

sqlAdapter = new SqlDataAdapter();

try
{
    sqlConnStr = new SqlConnection(ConfigurationManager.ConnectionStrings["PlacementConnectionString"].ConnectionString);
}

to 

sqlAdapter = new SqlDataAdapter();
string s = ConfigurationManager.ConnectionStrings[1].ConnectionString;

try
{
    sqlConnStr = new SqlConnection(s);
}

I inspect s and the value is 

Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\Placement.accdb

Now an error is thrown

System.ArgumentException: Keyword not supported: 'provider'

At wits' end;

=================================================================

TO EVERYONE - THANK YOU the problem was (I forgot) when using an Access database you have to use OleDbCommand and not SqlCommand. Thank you everything works fine now! – Markus just now edit

Upvotes: 1

Views: 5594

Answers (2)

Esen
Esen

Reputation: 973

Your connectionstring name is incorrect

<connectionStrings>
 <add name="_201103578_P09.Properties.Settings.PlacementConnectionString" 
    connectionString="Provider=Microsoft.ACE.OLEDB.12.0;DataSource=|DataDirectory|\Placement.accdb"
    providerName="System.Data.OleDb" />

Instead it should be

<connectionStrings>
<add name="PlacementConnectionString" 
    connectionString="Provider=Microsoft.ACE.OLEDB.12.0;DataSource=|DataDirectory|\Placement.accdb"
    providerName="System.Data.OleDb" />

Or in your code you should look for 

ConfigurationManager.ConnectionStrings["_201103578_P09.Properties.Settings.PlacementConnectionString"].ConnectionString

Upvotes: 1

OnResolve
OnResolve

Reputation: 4032

Going off the code you posted, the only explanation I can see is that the null reference you're getting is related to the configuration manager not getting anything by the string you're passing it.

if

ConfigurationManager.ConnectionStrings["PlacementConnectionString"]

doesn't return anything-- calling

.ConnectionString

will fail with your error. Can you verify that

"PlacementConnectionString"

is the correct name of the connection?

Upvotes: 1

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