Why does this code compile in one solution but not in another?

Question

I have this code in one solution, and it works fine:

        private readonly List<Department> departments = new List<Department>();

        . . .

        private void LoadDepartments(string serialNum)
        {
            string dbContext = HandheldServerUtils.GetDBContextForSerialNum(serialNum);
            string connStr =
                string.Format(
                    @"Provider=Microsoft.ACE.OLEDB.12.0;User ID=NRBQSP;Password=NRBQSP;Data Source=C:\CCRWin\DATA\CCRDAT{0}.MDB;Jet OLEDB:System database=C:\CCRWin\Data\sscs.mdw",
                    dbContext);
            using (var conn = new OleDbConnection(connStr))
            {
                using (OleDbCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandText =
                        @"SELECT t_accounts.account_no as AccountID, IIF(ISNULL(t_accounts.name),'[blank]',t_accounts.name) AS Name 
                        FROM t_accounts 
                        INNER JOIN td_department_accounts ON (t_accounts.account_no = 
td_department_accounts.account_no) where type = 'DE'";
                    cmd.CommandType = CommandType.Text;
                    conn.Open();
                    int i = 1;
                    using (OleDbDataReader oleDbD8aReader = cmd.ExecuteReader())
                    {
                        while (oleDbD8aReader != null && oleDbD8aReader.Read())
                        {
                            string accountNum = oleDbD8aReader.GetString(0);
                            string deptName = oleDbD8aReader.GetString(1);
                            Add(new Department {Id = i, AccountId = accountNum, Name = deptName});
                            i++;
                        }
                    }
                }
            }
        }

I have this very similar code in another:

    public IEnumerable<Department> GetDepartments()
    {
        private readonly List<Department> departments = new List<Department>();
        string dbContext = "42"; 
        string connStr =
            string.Format(
                @"Provider=Microsoft.ACE.OLEDB.12.0;User ID=NRBQSP;Password=NRBQSP;Data Source=C:\CCRWin\DATA\CCRDAT{0}.MDB;Jet OLEDB:System database=C:\CCRWin\Data\sscs.mdw",
                dbContext);
        using (var conn = new OleDbConnection(connStr))
        {
            using (OleDbCommand cmd = conn.CreateCommand())
            {
                cmd.CommandText =
                    @"SELECT t_accounts.account_no as AccountID, IIF(ISNULL(t_accounts.name),'[blank]',t_accounts.name) AS Name 
                    FROM t_accounts 
                    INNER JOIN td_department_accounts ON (t_accounts.account_no = td_department_accounts.account_no) where type = 'DE'";
                cmd.CommandType = CommandType.Text;
                conn.Open();
                int i = 1;
                using (OleDbDataReader oleDbD8aReader = cmd.ExecuteReader())
                {
                    while (oleDbD8aReader != null && oleDbD8aReader.Read())
                    {
                        string accountNum = oleDbD8aReader.GetString(0);
                        string deptName = oleDbD8aReader.GetString(1);
                        departments.Add(new Department { Id = i, AccountId = oleDbD8aReader.GetInt16(0), Name = oleDbD8aReader.GetString(1) });
                        i++;
                    }
                }                    
            }
        }
        return departments;
    }

...and it coughs up 26 Errors, such as:

"; expected"

on this line and others:

using (var conn = new OleDbConnection(connStr))

-and "} expected" right after the opening "{"

--and "A namespace cannot directly contain members such as fields or methods"

on this line:

departments.Add(new Department { Id = i, AccountId = oleDbD8aReader.GetInt16(0), Name = oleDbD8aReader.GetString(1) });

-and "Invalid token '!=' in class, struct, or interface member declaration" on this line:

while (oleDbD8aReader != null && oleDbD8aReader.Read())

...as well as many other "invalid token" errors for "(" and "," and ";" and "{" and "=" and "using"

-and two "Type or namespace definition, or end-of-file expected"

If I comment out all the code except a return statement so that it is just:

public IEnumerable<Department> GetDepartments()
{
    return null;
}

...it compiles fine.

Why is what is good for the goose not good for the gander here?

So you're saying that you tried some code in one project, and then you tried *different* code in another project, and you're wondering why the latter didn't compile? Something's wrong with your logic here. — Robert Harvey, Jul 15 '14 at 17:09
Looks like you forgot a `}` or `{` somewhere. Hard to point out without complete code. — derpirscher, Jul 15 '14 at 17:10
You have a `private` variable within your method in the second case. It's illegal. — dee-see, Jul 15 '14 at 17:11
@B.ClayShannon I doubt it. There is neither a class nor a namespace definiton. — derpirscher, Jul 15 '14 at 17:21
So the compiler gives me misleading err msgs, and everybody and his brother downvotes the questions, as if I'm expected to know better than the compiler! Weird... — B. Clay Shannon-B. Crow Raven, Jul 15 '14 at 17:42

score 4 · Accepted Answer · edited Jul 15 '14 at 17:12

4

This line ...

private readonly List<Department> departments = new List<Department>();

... should not be in the function, but outside, at the class scope, or make it a var.

edited Jul 15 '14 at 17:12

Code Maverick

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answered Jul 15 '14 at 17:10

JacksonHaenchen

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It's amazing how an oversight like that can conjure up myriads of hissing cobras, weaving menacingly and maliciously, when nothing more was needed than a friendly mongoose waving a "remove the private designation here" sign. – B. Clay Shannon-B. Crow Raven Jul 15 '14 at 17:19
It shouldn't be 'readonly' if the user is adding to it in the code below. – Cory Jul 15 '14 at 17:19
2

@KoBE It's perfectly legal to mutate an object assigned to a readonly field. You just can't reassign the field, that's all. – dcastro Jul 15 '14 at 17:26
@dcastro Is that so? Thanks for the info. I guess I recant my statement from earlier. I'll look into it further. Thanks! – Cory Jul 15 '14 at 17:29

Why does this code compile in one solution but not in another?

1 Answers1