關於字串

方法一：連線字串直接擺上來

  using (SqlConnection conn = new SqlConnection("Data Source=.\\SQLEXPRESS; Database=**;Integrated Security=False;User ID=**;Password=**"))
                {
                    conn.Open();

                    using (SqlCommand cmd = conn.CreateCommand())
                    {
                        cmd.CommandText = "*************";
                        
                        XXXXXXXXXXXX
                    }
                }
 

<configuration>
  <connectionStrings>
    <add name="dbCS" connectionString="Data Source=.\SQLEXPRESS; Database=**;Integrated Security=False;User ID=**;Password=**"/>
  </connectionStrings>

  string connStr = ConfigurationManager.ConnectionStrings["dbCS"].ConnectionString;
  using (SqlConnection conn = new SqlConnection(connStr))
            <pre name="code" class="csharp"> {
                    conn.Open();

                    using (SqlCommand cmd = conn.CreateCommand())
                    {
                        cmd.CommandText = "*************";
                        
                        XXXXXXXXXXXX
                    }
                }
 

關於SQL語句中的變數

在程式中SQL是以字串的形式存在的，因此新增變數時自然可以使用字串拼接的方式，如：

cmd.CommandText = "select * from XXX where xxx="+某個字串;

<span style="font-size:14px;">cmd.CommandText = "select * from  XXX where 
 
[email protected]";</span>
cmd.Parameters.Add(new SqlParameter("@Para", 某個字串));
//上面一條語句等價於 cmd.Parameters.AddWithValue("@Para", 某個字串);