JOIN
语句结合 数据库名.表名
语法。,,``sql,SELECT db1.table1.column1, db2.table2.column2,FROM db1.table1,JOIN db2.table2 ON db1.table1.common_field = db2.table2.common_field;,
``JOIN
语句结合 数据库名.表名
语法。,,``sql,SELECT db1.table1.column1, db2.table2.column2,FROM db1.table1,JOIN db2.table2 ON db1.table1.common_field = db2.table2.common_field;,
``mysql u 用户名 p e "SHOW VARIABLES LIKE 'hostname';"
。SELECT HOST;
语句查看当前连接主机。php,$db = new PDO('mysql:host=localhost;dbname=your_database', 'username', 'password');,$stmt = $db>query("SELECT * FROM your_table");,while ($row = $stmt>fetch()) {, echo $row['column_name'];,},
``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。Powered By Z-BlogPHP 1.7.3
Copyright Your WebSite.Some Rights Reserved.