What are the best practices for developing the class library as a whole and the database level?

Question

I am going to create a database layer to expose a set of functions that will provide reading and writing to our database. I have many questions related to this, and I want someone to advise

• How can I handle database exceptions (e.g. timeout exceptions) or leave the dll client to handle them

• The dll will not be thread safe, so should I use one connection for the dll instance? as it improves productivity.

• Are there general rules for developing a class library?

I am using C # vs2008 and SQL2008

Answer 1

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.

Customer GetCustomer(int id) {
    using(var conn = CreateConnection()) {
        conn.Open();
        // etc
    }
}

Answer 2

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