Fix code typo

Author: 元炜

de/09.4.md

@@ -32,7 +32,7 @@ If the user inputs a user name or password as:
 
 Then our SQL becomes the following:
 
-	SELECT * FROM user WHERE username='myuser' or 'foo'=='foo' --'' AND password='xxx'
+	SELECT * FROM user WHERE username='myuser' or 'foo' = 'foo' --'' AND password='xxx'
 
 In SQL, anything after `--` is a comment. Thus, inserting the `--` as the attacker did above alters the query in a fatal way, allowing an attacker to successfully login as a user without a valid password.
 

en/09.4.md

@@ -32,7 +32,7 @@ If the user inputs a user name or password as:
 
 Then our SQL becomes the following:
 
-	SELECT * FROM user WHERE username='myuser' or 'foo'=='foo' --'' AND password='xxx'
+	SELECT * FROM user WHERE username='myuser' or 'foo' = 'foo' --'' AND password='xxx'
 
 In SQL, anything after `--` is a comment. Thus, inserting the `--` as the attacker did above alters the query in a fatal way, allowing an attacker to successfully login as a user without a valid password.
 

ja/09.4.md

@@ -28,7 +28,7 @@ SQLインジェクションが発生する原因はプログラムがユーザ
 
 我々のSQLは以下のようになります：
 
-	SELECT * FROM user WHERE username='myuser' or 'foo'=='foo' --'' AND password='xxx'
+	SELECT * FROM user WHERE username='myuser' or 'foo' = 'foo' --'' AND password='xxx'
 
 SQLでは`--`はコメントを表します。そのため、検索クエリは途中で中断されます。攻撃者は合法的なユーザ名とパスワードを知らなくてもログインに成功します。
 

pt-br/09.4.md

@@ -32,7 +32,7 @@ If the user inputs a user name or password as:
 
 Then our SQL becomes the following:
 
-	SELECT * FROM user WHERE username='myuser' or 'foo'=='foo' --'' AND password='xxx'
+	SELECT * FROM user WHERE username='myuser' or 'foo' = 'foo' --'' AND password='xxx'
 
 In SQL, anything after `--` is a comment. Thus, inserting the `--` as the attacker did above alters the query in a fatal way, allowing an attacker to successfully login as a user without a valid password.
 

zh/09.4.md

@@ -35,7 +35,7 @@ SQL注入攻击（SQL Injection），简称注入攻击，是Web开发中最常
 那么我们的SQL变成了如下所示：
 ```Go
 
-	SELECT * FROM user WHERE username='myuser' or 'foo'=='foo' --'' AND password='xxx'
+	SELECT * FROM user WHERE username='myuser' or 'foo' = 'foo' --'' AND password='xxx'
 ```
 在SQL里面`--`是注释标记，所以查询语句会在此中断。这就让攻击者在不知道任何合法用户名和密码的情况下成功登录了。