My database class

[craigclister]

I'm writing a small 'learning' app. It uses SQL Server.

I am trying to create a common class of database functions. So, am I
right in saying that it should be a static class? I've done that, but
then I can't declare a private class variable, because the class is
static...

internal static class Database
{
internal SqlConnection conn = new SqlConnection(); <---
Error...

internal static bool Connect()
{
try
{
conn.ConnectionString = "Data Source=localhost;
Integrated Security=SSPI; Initial Catalog=HomeShopper";
conn.Open();
return true;
}
catch(Exception e)
{.................................

How should I be doing this? I'd like to then be able to:

Common.Database.Connect();

 

[Jon Skeet [C# MVP]]

I'm writing a small 'learning' app. It uses SQL Server.

I am trying to create a common class of database functions. So, am I
right in saying that it should be a static class? I've done that, but
then I can't declare a private class variable, because the class is
static...

internal static class Database
{
internal SqlConnection conn = new SqlConnection(); <---
Error...

internal static bool Connect()
{
try
{
conn.ConnectionString = "Data Source=localhost;
Integrated Security=SSPI; Initial Catalog=HomeShopper";
conn.Open();
return true;
}
catch(Exception e)
{.................................

How should I be doing this? I'd like to then be able to:

Common.Database.Connect();

Well, to do that you could make conn static (preferrably private, too)
- but maintaining a single static connection isn't a generally good
idea. It's better to open the connection when need it, and close it
immediately after you've used it, e.g. in a using statement.

 

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

If the class is static then it should contani only static members. Not only
that but that code should not compile and should give you an error that a
static class can only contains static members.

 

[craigclister]

It's better to open the connection when need it, and close it

immediately after you've used it, e.g. in a using statement.

Thanks (again) John. Can you give an example of the Using?
I guess you mean if I have a 'getData' type function which I pass an
SQL statement to, and returns a recordset, then the getData would open
the connection, do the query, return the data and close the connection?

 

[Jon Skeet [C# MVP]]

Thanks (again) John. Can you give an example of the Using?

The using statement is something like:

using (SqlConnection conn = new SqlConnection())
{
// Use conn here
}
// conn has automatically been closed (Dispose has been called) even
// if an exception is thrown

I guess you mean if I have a 'getData' type function which I pass an
SQL statement to, and returns a recordset, then the getData would open
the connection, do the query, return the data and close the connection?

Exactly.