如何將這個查詢轉換爲笨

Question

的LINQ我不明白如何將這個查詢轉換成笨LINQ

SELECT prdctSubCatId 
FROM productinfo 
WHERE prdctSubCatId = (
    SELECT prdctSubCatId 
    FROM productinfo 
    WHERE id='27' 

） 而是ID = '27' 我想通過ID = $ ID的，然後，我怎麼能做到這一點

Answer 1

$this->db->select('prdctSubCatId')->from('productinfo'); 
$this->db->where('`prdctSubCatId`= (SELECT `prdctSubCatId` FROM `productinfo` WHERE id=27)', NULL, FALSE); 

Answer 2

只需使用

$query = $this->db->query("SELECT prdctSubCatId FROM productinfo WHERE prdctSubCatId=27"); 
$result = $query->result_array(); 
return $result; 

Answer 3

$this->db->select('prdctSubCatId'); 
    $this->db->where('id',27); 
    return $this->db->get('productinfo')->result_array();