如何在 in sql 语句中使用 like

How to use like in an in sql statement

您好,我正在使用 PHP 尝试从数据库中检索数据,同时像这样在 in 语句中循环遍历数组。

$sql2 = "SELECT * FROM pixacour_pixacourt.UserCaseMessages WHERE FavorIDs IN  (" ;
    $count = 0;
foreach($followingArray as $value)
{
    if($count==count($followingArray)-1)
    {
        $sql2 .= "LIKE";
        $sql2 .= "%'".$value."'%";
    }
    else
    {
        $sql2 .= "LIKE";
        $sql2 .= "%'".$value."'%,";        
    }
    ++$count;
}
$sql2 .= ")";

我收到这个错误,上面写着

"trying to get property of non object"

我不知道发生了什么任何建议将不胜感激感谢您的时间。

您不应在 IN 子句中使用 LIKE,但您确实需要用逗号分隔元素。也不需要跟踪计数。 foreach 将在遍历数组后停止,您可以 trim 关闭尾随逗号。

$sql2 = "SELECT * FROM pixacour_pixacourt.UserCaseMessages WHERE FavorIDs IN  (" ;
foreach($followingArray as $value)
{
        $sql2 .= "'".$value."', ";        
}
$sql2 = rtrim($sql2,',');
$sql2 .= ");";

如果失败,如 Gordon 所说,回显 $sql2,语法错误可能会很清楚。

如果您确实需要使用 LIKE 和通配符匹配,您可以附加多个 OR 子句,每个 $value 一个。

$sql2 = "SELECT * FROM pixacour_pixacourt.UserCaseMessages WHERE " ;
$whereClause = "";
foreach($followingArray as $value)
{
        $whereClause .= " OR FavorIDs LIKE '%".$value."%' ";        
}
$whereClause = ltrim($whereClause, " OR");
$sql2 .= $whereClause . ";";

更新 1/9/15

我意识到此代码中存在错误,当 $followingArray 为空时,我们会收到 MySQL 语法错误,因为查询以 "WHERE" 结尾。这是解决该错误的新版本:

$sql2 = "SELECT * FROM pixacour_pixacourt.UserCaseMessages" ;
if(count($followingArray) >= 1) {
    $sql2 .= " WHERE";
}
$whereClause = "";
foreach($followingArray as $value)
{
        $whereClause .= " OR FavorIDs LIKE '%".$value."%' ";        
}
$whereClause = ltrim($whereClause, " OR");
$sql2 .= $whereClause . ";";