如果MySQL查询

Question

我有一个包含几乎相同的信息，现在三个不同的PHP页面内参数，因此能够将这一数字减少到一个页面，我需要有mysql的查询中一个PHP变量。 今天，它是这样的：

$query1 = "SELECT * FROM `Yrker` WHERE `Kategori` = '1' AND `Bruk` = '1' ORDER BY yearstart DESC, mndstart DESC";` 

我需要的是“AND Bruk =‘1’”从该查询行中删除，如果我把nobruk =没有在adressbar？这是可能的，如果是这样，如何？

Answer 1

您不想（也不能）将if放入查询中;你想使用和if来创建您的查询基于某些条件。有很多方法来写这篇文章，其中之一是

if (!empty($_GET['nobruk'])) { 
    $query1 = "SELECT ... WHERE `Kategori` = '1' ORDER BY ..."; 
} 
else { 
    $query1 = "SELECT ... WHERE `Kategori` = '1' AND `Bruk` = '1' ORDER BY ..."; 
} 

另一种方式，这是短，涉及ternary operator，是

$includeBruk = empty($_GET['nobruk']); 
$query1 = "SELECT ... WHERE `Kategori` = '1' ". 
      ($includeBruk ? "AND `Bruk` = '1' " : ""). 
      "ORDER BY ..."; 

Answer 2

一个简单的if语句：

$query1 = "SELECT * FROM `Yrker` WHERE `Kategori` = '1'"; 
    if ($_GET['nobruk']!='no') { 
    $query1.=" AND `Bruk` = '1'"; 
    } 
$query1.= " ORDER BY yearstart DESC, mndstart DESC"; 

Answer 3

喜欢分享：

<?php 

$query = ($_REQUEST['nobruk'] == "no") ? "SELECT * FROM `Yrker` WHERE `Kategori` = '1' ORDER BY yearstart DESC, mndstart DESC": "SELECT * FROM `Yrker` WHERE `Kategori` = '1' AND `Bruk` = '1' ORDER BY yearstart DESC, mndstart DESC"; 
echo $query; 
?> 

Answer 4

$query1 = "SELECT * FROM `Yrker` WHERE `Kategori`='1' ".($_GET['nobruk'] === 'no' ? "" : "AND `Bruk`='1' ")."ORDER BY yearstart DESC, mndstart DESC";