csharp,protected void Page_Load(object sender, EventArgs e),{, string connectionString = "Data Source=server;Initial Catalog=database;User Id=user;Password=password";, using (SqlConnection con = new SqlConnection(connectionString)), {, string query = "SELECT * FROM Users WHERE UserName='John'";, SqlCommand cmd = new SqlCommand(query, con);, con.Open();, SqlDataReader reader = cmd.ExecuteReader();, while (reader.Read()), {, Response.Write("User ID: " + reader["UserID"].ToString() + "");, }, reader.Close();, },},
``,这段代码连接到一个名为“database”的数据库,从“Users”表中查询用户名为“John”的用户信息,并将用户ID输出到网页上。DATE_SUB
函数结合 NOW()
函数来按时间间隔查询数据。要查询过去7天内的数据,可以使用以下SQL语句:,,``sql,SELECT * FROM your_table WHERE your_date_column >= DATE_SUB(NOW(), INTERVAL 7 DAY);,
``YEAR()
和MONTH()
函数按月份查询数据。,,``sql,SELECT * FROM table_name WHERE YEAR(date_column) = 2021 AND MONTH(date_column) = 5;,
``,,这条SQL语句将查询2021年5月的数据。Powered By Z-BlogPHP 1.7.3
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