无法在php mysql中使用联合

$query1 = "SELECT column1, column2 FROM table1";
$query2 = "SELECT column1, column2 FROM table2";
$combinedQuery = "SELECT column1, column2 FROM ($query1 UNION ALL $query2) AS combined_table";

$result = mysqli_query($connection, $combinedQuery);

$query1 = "SELECT column1, column2 FROM table1";
$query2 = "SELECT column1, column2 FROM table2";

// 创建临时表
$tempTable = "CREATE TEMPORARY TABLE temp_table (column1 VARCHAR(255), column2 VARCHAR(255))";

// 插入第一个查询结果到临时表
$insertQuery1 = "INSERT INTO temp_table (column1, column2) $query1";

// 插入第二个查询结果到临时表
$insertQuery2 = "INSERT INTO temp_table (column1, column2) $query2";

// 从临时表中检索数据
$selectQuery = "SELECT column1, column2 FROM temp_table";

// 执行查询
mysqli_query($connection, $tempTable);
mysqli_query($connection, $insertQuery1);
mysqli_query($connection, $insertQuery2);
$result = mysqli_query($connection, $selectQuery);