feat:优化mysqlCli

 <?php
+
 namespace Jiaoyin;
 
 use Swoole\Database\MysqliConfig;
@@ -10,24 +11,24 @@ class MysqlCli
     private $pool   = null;
     private $prefix = '';// 前缀
 
-    private int $reconnectCount   = 0; //period时间内重连次数
-    private int $period           = 300;
+    private int $reconnectCount    = 0; //period时间内重连次数
+    private int $period            = 300;
     private int $lastReconnectTime = 0;
-    private     $connectConfig    = null;
-    private $database = null;
+    private     $connectConfig     = null;
+    private     $database          = null;
 
-    public function __construct($host,$port,$database,$username,$password,$charset='utf8',$prefix='', $connectCount = 20)
+    public function __construct($host, $port, $database, $username, $password, $charset = 'utf8', $prefix = '', $connectCount = 20)
     {
-        $this->database = $database;
-        $this->prefix = $prefix;
+        $this->database      = $database;
+        $this->prefix        = $prefix;
         $this->connectConfig = [
-            'host' => $host,
-            'port' => $port,
-            'database' => $database,
-            'username' => $username,
-            'password' => $password,
-            'charset' => $charset,
-            'prefix' => $prefix,
+            'host'         => $host,
+            'port'         => $port,
+            'database'     => $database,
+            'username'     => $username,
+            'password'     => $password,
+            'charset'      => $charset,
+            'prefix'       => $prefix,
             'connectCount' => $connectCount,
         ];
         $this->poolConnect();
@@ -35,17 +36,17 @@ class MysqlCli
 
     private function poolConnect()
     {
-        if($this->pool){
+        if ($this->pool) {
             $this->pool->close();
         }
-        $this->pool  = new MysqliPool((new MysqliConfig)
+        $this->pool   = new MysqliPool((new MysqliConfig)
             ->withHost($this->connectConfig['host'])
             ->withPort($this->connectConfig['port'])
             ->withDbName($this->connectConfig['database'])
             ->withCharset($this->connectConfig['charset'])
             ->withUsername($this->connectConfig['username'])
             ->withPassword($this->connectConfig['password'])
-            ,$this->connectConfig['connectCount']
+            , $this->connectConfig['connectCount']
         );
         $this->prefix = $this->connectConfig['prefix'];
     }
@@ -116,7 +117,7 @@ class MysqlCli
         $data    = $this->execute('SELECT', $sql);
         $newData = [];
         if (empty($col)) {
-            $newsql  = 'SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = "'.$this->database.'" AND TABLE_NAME="' . $this->parseTable($table) . '" ORDER BY `ORDINAL_POSITION` ASC';
+            $newsql  = 'SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = "' . $this->database . '" AND TABLE_NAME="' . $this->parseTable($table) . '" ORDER BY `ORDINAL_POSITION` ASC';
             $coldata = $this->execute('SELECT', $newsql);
             if (!$coldata) {
                 return false;
@@ -208,9 +209,13 @@ class MysqlCli
                     return false;
                 }
                 $value[1] = $this->transferValue($value[1]);
-                $symbol   = isset($value[2]) ? $value[2] : '=';
-                $tmp      .= $value[0] . ' ' . $symbol . ' ' . $value[1];
-                $tmp      .= $key < count($where) - 1 ? ' and ' : '';
+                if ($value[1] === 'NULL') {
+                    $tmp = $value[0] . ' is NULL';
+                } else {
+                    $symbol = $value[2] ?? '=';
+                    $tmp    .= $value[0] . ' ' . $symbol . ' ' . $value[1];
+                }
+                $tmp .= $key < count($where) - 1 ? ' and ' : '';
             }
             $whereTxt .= $tmp;
         } else {