分类和数据在一张表中

想做个分类搜索

先把分类取出来

$typename = db('riddle')->limit(5)->group('typename')->field('typename')->select()->toArray();

得到

array(5) {
 [0] => array(1) {
    ["typename"] => string(12) "书报谜语"
  }
  [1] => array(1) {
    ["typename"] => string(12) "人名谜语"
  }
  [2] => array(1) {
    ["typename"] => string(12) "俗语谜语"
  }
  [3] => array(1) {
    ["typename"] => string(12) "动物谜语"
  }
  [4] => array(1) {
    ["typename"] => string(12) "名谜谜语"
  }
}

只需要键值，所以做了处理
$arr2      = array_map('array_shift', $typename);
$arr2     = array_column($typename, 'typename');

两种取数据方法
得到

array(5) {
  [0] => string(12) "书报谜语"
  [1] => string(12) "人名谜语"
  [2] => string(12) "俗语谜语"
  [3] => string(12) "动物谜语"
  [4] => string(12) "名谜谜语"
}

OK