19 Execute select * from user where username = 'hack' and password = '\' or \'1\'=\'1' 19 Close stmt 19 Quit 原来是运行了:select * from user where username = 'hack' and password = '\' or \'1\'=\'1' 【參考】 JDBC Statement vs PreparedStatement – SQL Injection Example(推荐)...
Statement.也就是说,在任何时候都不要使用Statement.基于以下的原因:一.代码的可读性和可维护性.虽然用PreparedStatement来代替Statement会使代码多出几行,但这样的代码无论从可读性还是可维护性上来说.都比直接用Statement的代码高很多档次:stmt.executeUpdate("insert into tb_name (col1,col2,col2,col...
Executes the given SQL statement, which may be an INSERT, UPDATE, or DELETE statement or an SQL statement that returns nothing, such as an SQL DDL statement. int executeUpdate(String sql, int autoGeneratedKeys) Executes the given SQL statement and signals the driver with the given flag about...
你就应该始终以PreparedStatement代替Statement.也就是说,在任何时候都不要使用Statement一.代码的可读性和可维护性.虽然用PreparedStatement来代替Statement会使代码多出几行,但这样的代码无论从可读性还是可维护性上来说.都比直接用Statement的代码高很多档次:stmt.executeUpdate("insert into tb_name (col1,...
jshell> /help | Type a Java language expression, statement, or declaration. | Or type one of the following commands: | /list [<name or id>|-all|-start] | list the source you have typed | /edit <name or id> | edit a source entry referenced by name or id | /drop <name or id...
Statement.execute(java.lang.String), Statement.getResultSet(), Statement.getUpdateCount(), Statement.getMoreResults() addBatch void addBatch() throws SQLException このPreparedStatementオブジェクトのコマンドのバッチに、パラメータのセットを追加します。 例外: SQLException - データベース・アクセ...
Statement Statement StatementEvent StatementEventListener StAXResult StAXSource Streamable StreamableValue StreamCorruptedException StreamFilter StreamHandler StreamPrintService StreamPrintServiceFactory StreamReaderDelegate StreamResult StreamSource StreamTokenizer StrictMath String StringBuffe...
userName ="1' OR '1'='1"; passWord ="1' OR '1'='1"; 那么最终SQL语句变成了: 1 strSQL ="SELECT * FROM users WHERE name = '1' OR '1'='1' and pw = '1' OR '1'='1';" 因为WHERE条件恒为真,这就相当于执行: 1 strSQL ="SELECT * FROM users;" ...
2.5 优点四:ParperStatement比Statement好的优点,那就是安全 你说啥?这还关安全啥事儿,那我给你一行代码,你来给我说说这是干嘛的。 String sql = "select * from user where username= '"+varname+"' and userpwd='"+varpasswd+"'"; stmt = conn.createStatement(); ...
编译器抛出“Missing Return Statement”消息的原因有若干: 返回语句由于错误被省略。 该方法没有返回任何值,但类型void在方法签名中未声明。 查看如何修复“Missing Return Statement”Java软件错误的示例。(@StackOverflow) 10.“Possible Loss of Precision” 当更多的信息被分配给一个变量而超过它的容量,就会发生“...