尝试在变量前后添加“%”，如下所示。

$question = "What is your Name";
$query = "SELECT * FROM `def_questions` where `question` LIKE '%$question%' ";

编辑以防止sql注入只需执行以下操作：

$question = mysql_real_escape_string($question);

如果想要得到精确的结果，可以使用=而不是like

$question = "What is your Name";
$query = "SELECT * FROM `def_questions` where `question` = '$question'"

$question = rtrim(ltrim(strip_tags(What is your Name)));
$query = "SELECT * FROM `def_questions` where `question` LIKE '%$question%' ";

您的代码可能易受sql注入攻击。您应该使用准备好的语句来传递要查询的值：

$questions = Yii::$app->db
    ->createCommand("SELECT * FROM `def_questions` where `question` LIKE :question", [
        ':question' => "%$question%",
    ])
    ->queryAll();

请注意，您还应该从搜索值中转义一些特殊字符，以使其能够正确使用 LIKE 运算符（例如） % 作为 % 请参阅如何在like中使用百分比（%）而不将其视为通配符？），而不是“anything”：

$question = strtr($question, [
    '%' => '\%',
    '_' => '\_',
    '\\' => '\\\\',
]);
$questions = Yii::$app->db
    ->createCommand("SELECT * FROM `def_questions` where `question` LIKE :question", [
        ':question' => "%$question%",
    ])
    ->queryAll();

最简单的方法是使用 Query :

$questions = (new \yii\db\Query())
    ->from('def_questions')
    ->where(['like', 'question', $question])
    ->all();
``` `Query` 将为您执行转义并返回sql查询的结果：

SELECT * FROM def_questions where question LIKE '%What is your Name%'