PHPMySQL中合并来自5个不同数据库的数据

要合并来自5个不同的MySQL数据库中的数据，需要使用MySQL连接（或称为MySQL联接）来检索并组合这些数据。以下是一个简单的示例代码，演示如何连接到5个不同的MySQL数据库并检索数据：

//建立与第一个数据库的连接 $con1 = mysqli_connect("host1", "username1", "password1", "database1"); //建立与第二个数据库的连接 $con2 = mysqli_connect("host2", "username2", "password2", "database2"); //建立与第三个数据库的连接 $con3 = mysqli_connect("host3", "username3", "password3", "database3"); //建立与第四个数据库的连接 $con4 = mysqli_connect("host4", "username4", "password4", "database4"); //建立与第五个数据库的连接 $con5 = mysqli_connect("host5", "username5", "password5", "database5");

//查询每个数据库的数据（假设它们都有一个名为“table”的表） $result1 = mysqli_query($con1, "SELECT * FROM table"); $result2 = mysqli_query($con2, "SELECT * FROM table"); $result3 = mysqli_query($con3, "SELECT * FROM table"); $result4 = mysqli_query($con4, "SELECT * FROM table"); $result5 = mysqli_query($con5, "SELECT * FROM table");

//将所有结果合并到一个数组中 $data = array();

while($row = mysqli_fetch_array($result1)) { $data[] = $row; } while($row = mysqli_fetch_array($result2)) { $data[] = $row; } while($row = mysqli_fetch_array($result3)) { $data[] = $row; } while($row = mysqli_fetch_array($result4)) { $data[] = $row; } while($row = mysqli_fetch_array($result5)) { $data[] = $row; }

//按需要对数据进行排序或其他操作 //例如，按ID对数据进行排序 usort($data, function($a,