diff --git a/composer.json b/composer.json
index 2274ac8..0d375b4 100644
--- a/composer.json
+++ b/composer.json
@@ -36,6 +36,7 @@
     ],
     "require": {
         "ext-json": "*",
+        "ext-pdo": "*",
         "guanguans/soar-php": "^2.5",
         "illuminate/console": "^6.10 || ^7.0 || ^8.0 || ^9.0",
         "illuminate/contracts": "^6.10 || ^7.0 || ^8.0 || ^9.0",
diff --git a/src/Support/QueryAnalysis.php b/src/Support/QueryAnalysis.php
new file mode 100644
index 0000000..13bbace
--- /dev/null
+++ b/src/Support/QueryAnalysis.php
@@ -0,0 +1,165 @@
+<?php
+
+/**
+ * This file is part of the guanguans/laravel-soar.
+ *
+ * (c) guanguans <ityaozm@gmail.com>
+ *
+ * This source file is subject to the MIT license that is bundled.
+ */
+
+namespace Guanguans\LaravelSoar\Support;
+
+use DateTime;
+use PDO;
+
+class QueryAnalysis
+{
+    /**
+     * KEYWORDS1.
+     *
+     * @var string
+     */
+    public const KEYWORDS1 = 'SELECT|(?:ON\s+DUPLICATE\s+KEY)?UPDATE|INSERT(?:\s+INTO)?|REPLACE(?:\s+INTO)?|DELETE|CALL|UNION|FROM|WHERE|HAVING|GROUP\s+BY|ORDER\s+BY|LIMIT|OFFSET|SET|VALUES|LEFT\s+JOIN|INNER\s+JOIN|TRUNCATE';
+
+    /**
+     * KEYWORDS2.
+     *
+     * @var string
+     */
+    public const KEYWORDS2 = 'ALL|DISTINCT|DISTINCTROW|IGNORE|AS|USING|ON|AND|OR|IN|IS|NOT|NULL|[RI]?LIKE|REGEXP|TRUE|FALSE';
+
+    /**
+     * Returns syntax highlighted SQL command.
+     *
+     * @param string $sql
+     * @param \PDO   $pdo
+     *
+     * @return string
+     */
+    public static function highlight($sql, array $bindings = [], PDO $pdo = null)
+    {
+        // insert new lines
+        $sql = " $sql ";
+        $sql = preg_replace('#(?<=[\\s,(])('.static::KEYWORDS1.')(?=[\\s,)])#i', "\n\$1", $sql);
+
+        // reduce spaces
+        $sql = preg_replace('#[ \t]{2,}#', ' ', $sql);
+
+        // syntax highlight
+        $sql = htmlspecialchars($sql, ENT_IGNORE, 'UTF-8');
+        $sql = preg_replace_callback('#(/\\*.+?\\*/)|(\\*\\*.+?\\*\\*)|(?<=[\\s,(])('.static::KEYWORDS1.')(?=[\\s,)])|(?<=[\\s,(=])('.static::KEYWORDS2.')(?=[\\s,)=])#is', function ($matches) {
+            if (! empty($matches[1])) { // comment
+                return '<em style="color:gray">'.$matches[1].'</em>';
+            } elseif (! empty($matches[2])) { // error
+                return '<strong style="color:red">'.$matches[2].'</strong>';
+            } elseif (! empty($matches[3])) { // most important keywords
+                return '<strong style="color:blue; text-transform: uppercase;">'.$matches[3].'</strong>';
+            } elseif (! empty($matches[4])) { // other keywords
+                return '<strong style="color:green">'.$matches[4].'</strong>';
+            }
+        }, $sql);
+
+        $bindings = array_map(function ($binding) use ($pdo) {
+            if (true === is_array($binding)) {
+                $binding = implode(', ', array_map(function ($value) {
+                    return true === is_string($value) ? htmlspecialchars('\''.$value.'\'', ENT_NOQUOTES, 'UTF-8') : $value;
+                }, $binding));
+
+                return htmlspecialchars('('.$binding.')', ENT_NOQUOTES, 'UTF-8');
+            }
+
+            if (true === is_string($binding) && (preg_match('#[^\x09\x0A\x0D\x20-\x7E\xA0-\x{10FFFF}]#u', $binding) || preg_last_error())) {
+                return '<i title="Length '.strlen($binding).' bytes">&lt;binary&gt;</i>';
+            }
+
+            if (true === is_string($binding)) {
+                $text = htmlspecialchars($pdo ? $pdo->quote($binding) : '\''.$binding.'\'', ENT_NOQUOTES, 'UTF-8');
+
+                return '<span title="Length '.strlen($text).' characters">'.$text.'</span>';
+            }
+
+            if (true === is_resource($binding)) {
+                $type = get_resource_type($binding);
+                if ('stream' === $type) {
+                    $info = stream_get_meta_data($binding);
+                }
+
+                return '<i'.(isset($info['uri']) ? ' title="'.htmlspecialchars($info['uri'], ENT_NOQUOTES, 'UTF-8').'"' : null)
+                       .'>&lt;'.htmlspecialchars($type, ENT_NOQUOTES, 'UTF-8').' resource&gt;</i>';
+            }
+
+            if ($binding instanceof DateTime) {
+                return htmlspecialchars('\''.$binding->format('Y-m-d H:i:s').'\'', ENT_NOQUOTES, 'UTF-8');
+            }
+
+            return htmlspecialchars($binding, ENT_NOQUOTES, 'UTF-8');
+        }, $bindings);
+        $sql = str_replace(['%', '?'], ['%%', '%s'], $sql);
+
+        return '<div><code>'.nl2br(trim(vsprintf($sql, $bindings))).'</code></div>';
+    }
+
+    /**
+     * perform query analysis hint.
+     *
+     * @param string $sql
+     * @param string $version
+     * @param float  $driver
+     *
+     * @return array
+     */
+    public static function performQueryAnalysis($sql, $version = null, $driver = null)
+    {
+        $hints = [];
+        if (preg_match('/^\\s*SELECT\\s*`?[a-zA-Z0-9]*`?\\.?\\*/i', $sql)) {
+            $hints[] = 'Use <code>SELECT *</code> only if you need all columns from table';
+        }
+        if (preg_match('/ORDER BY RAND()/i', $sql)) {
+            $hints[] = '<code>ORDER BY RAND()</code> is slow, try to avoid if you can.
+                You can <a href="http://stackoverflow.com/questions/2663710/how-does-mysqls-order-by-rand-work">read this</a>
+                or <a href="http://stackoverflow.com/questions/1244555/how-can-i-optimize-mysqls-order-by-rand-function">this</a>';
+        }
+        if (false !== strpos($sql, '!=')) {
+            $hints[] = 'The <code>!=</code> operator is not standard. Use the <code>&lt;&gt;</code> operator to test for inequality instead.';
+        }
+        if (false === stripos($sql, 'WHERE')) {
+            $hints[] = 'The <code>SELECT</code> statement has no <code>WHERE</code> clause and could examine many more rows than intended';
+        }
+        if (preg_match('/LIMIT\\s/i', $sql) && false === stripos($sql, 'ORDER BY')) {
+            $hints[] = '<code>LIMIT</code> without <code>ORDER BY</code> causes non-deterministic results, depending on the query execution plan';
+        }
+        if (preg_match('/LIKE\\s[\'"](%.*?)[\'"]/i', $sql, $matches)) {
+            $hints[] = 'An argument has a leading wildcard character: <code>'.$matches[1].'</code>.
+                The predicate with this argument is not sargable and cannot use an index if one exists.';
+        }
+        if ($version < 5.5 && 'mysql' === $driver) {
+            if (preg_match('/\\sIN\\s*\\(\\s*SELECT/i', $sql)) {
+                $hints[] = '<code>IN()</code> and <code>NOT IN()</code> subqueries are poorly optimized in that MySQL version : '.$version.
+                           '. MySQL executes the subquery as a dependent subquery for each row in the outer query';
+            }
+        }
+
+        return $hints;
+    }
+
+    /**
+     * explain sql.
+     *
+     * @param string $sql
+     * @param array  $bindings
+     *
+     * @return array
+     */
+    public static function explain(PDO $pdo, $sql, $bindings = [])
+    {
+        $explains = [];
+        if (preg_match('#\s*\(?\s*SELECT\s#iA', $sql)) {
+            $statement = $pdo->prepare('EXPLAIN '.$sql);
+            $statement->execute($bindings);
+            $explains = $statement->fetchAll(PDO::FETCH_CLASS);
+        }
+
+        return $explains;
+    }
+}