Question

我是使用c＃和sqlite的新手。

为什么这段代码不起作用？我尝试了一点点不同。但没有成功。

    private void button1_Click(object sender, EventArgs e)
    {
        using (SQLiteConnection con = new SQLiteConnection(connectionString))
        {
            con.Open();
            try
            {
                SQLiteCommand cmd = new SQLiteCommand();
                const string createTableQuery = @"CREATE TABLE User userName NOT NULL varchar(40), passWord NOT NULL varchar(40))";
                cmd.CommandText = createTableQuery;
                cmd.ExecuteNonQuery();

                int i = cmd.ExecuteNonQuery();

                if (i == 1)
                {
                    MessageBox.Show("Table created");
                }
            }

            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            } 
        }

    }

Answer 1

你应该执行命令

private void button1_Click(object sender, EventArgs e)
{
    using (SQLiteConnection con = new SQLiteConnection(connectionString))
    {
        try
        {
            string createTableQuery = @"CREATE TABLE User (userName NOTNULL varchar(40), passWord NOTNULL varchar(40))";
            SQLiteCommand cmd = new SQLiteCommand();
            cmd.CommandText = createTableQuery;
            cmd.ExecuteNonQuery();//Here
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }  
    }

}

Answer 2

您的查询错误：

    string createTableQuery = @"CREATE TABLE User (userName NOTNULL 
varchar(40), passWord NOTNULL varchar(40))";

它应该是NOT NULL而不是NOTNULL：

    string createTableQuery = @"CREATE TABLE User (userName NOT NULL
 varchar(40), passWord NOT NULL varchar(40))";

然后致电：

    cmd.ExecuteNonQuery();

后：

cmd.CommandText = createTableQuery;

Answer 3

执行你的命令：

try
        {
            string createTableQuery = @"CREATE TABLE User (userName NOTNULL varchar(40), passWord NOTNULL varchar(40))";
            SQLiteCommand cmd = new SQLiteCommand();
            cmd.CommandText = createTableQuery;
            cmd.ExecuteNonQuery();
        }

为什么这段代码没有成为一张桌子？

3 个答案: