Php 在数据库中使用运算符？

^这是我的数据库表，“firstCheck”中有一个变量，“comparison”中有一个运算符，“secondCheck”中有一个值

//some code here where I fetch everything
if ($event0FirstCheck . $event0Operator . $event0SecondCheck) {
        $output .= $event0output;
    } else if ($event1FirstCheck . $event1Operator . $event1SecondCheck) {
        $output .= $event1output;
    } else {
        $output .= "something went wrong...";   
    }

如果我回显If，则这是输出：$gold>=100

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如果我重复ELSE if，那么这就是输出：$gold这可以做到是的，但不是没有常规的条件语句，而是通过创建自己的类或函数

示例

function condition($var1, $op, $var2) {

    switch ($op) {
        case "=":  return $var1 == $var2;
        case "!=": return $var1 != $var2;
        case ">=": return $var1 >= $var2;
        case "<=": return $var1 <= $var2;
        case ">":  return $var1 >  $var2;
        case "<":  return $var1 <  $var2;
    default:       return true;
    }   
}

if (condition($event0FirstCheck, $event0Operator, $event0SecondCheck)) {
    $output .= $event0FirstCheck.$event0Operator.$event0SecondCheck;
} else if (condition($event1FirstCheck, $event1Operator, $event1SecondCheck)) {
    $output .= $event1FirstCheck.$event1Operator.$event1SecondCheck;
} else {
    $output .= "something went wrong...";   
}

$a1 = '$gold';
$b1 = 150;
$com1 = ">=";

$a2 = '$gold';
$b2 = 150;
$com2 = "<";

$gold = 100;

$str = 'if('.$a1.' '.$com1.' '.$b1.'){echo "'.$a1.' '.$com1.' '.$b1.'";}elseif('.$a2.' '.$com2.' '.$b2.'){echo "'.$a2.' '.$com2.' '.$b2.'";}else{echo "something is wrong...";}';
eval($str);

---

这是可以做到的，但不是没有常规的条件语句，而是通过创建自己的类或函数

示例

function condition($var1, $op, $var2) {

    switch ($op) {
        case "=":  return $var1 == $var2;
        case "!=": return $var1 != $var2;
        case ">=": return $var1 >= $var2;
        case "<=": return $var1 <= $var2;
        case ">":  return $var1 >  $var2;
        case "<":  return $var1 <  $var2;
    default:       return true;
    }   
}

if (condition($event0FirstCheck, $event0Operator, $event0SecondCheck)) {
    $output .= $event0FirstCheck.$event0Operator.$event0SecondCheck;
} else if (condition($event1FirstCheck, $event1Operator, $event1SecondCheck)) {
    $output .= $event1FirstCheck.$event1Operator.$event1SecondCheck;
} else {
    $output .= "something went wrong...";   
}

$a1 = '$gold';
$b1 = 150;
$com1 = ">=";

$a2 = '$gold';
$b2 = 150;
$com2 = "<";

$gold = 100;

$str = 'if('.$a1.' '.$com1.' '.$b1.'){echo "'.$a1.' '.$com1.' '.$b1.'";}elseif('.$a2.' '.$com2.' '.$b2.'){echo "'.$a2.' '.$com2.' '.$b2.'";}else{echo "something is wrong...";}';
eval($str);

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感谢Fabio添加图像。感谢Fabio添加图像。