Statement和PreparedStatement的区别

预处理语句是Statement的一个稍微强大一点的版本，并且应该总是至少像Statement一样快速和容易处理。预估报表可以被参数化

大多数关系数据库处理JDBC / SQL查询分为四个步骤:

解析传入的SQL查询编译SQL查询规划/优化数据采集路径执行优化的查询/获取和返回数据

对于发送到数据库的每个SQL查询，Statement将始终执行上述四个步骤。预处理语句预先执行上述执行过程中的步骤(1)-(3)。因此，在创建准备语句时，会立即执行一些预优化。其效果是在执行时减轻数据库引擎的负载。

现在我的问题是:

“使用预准备报表还有其他好处吗?”

当前回答

PreparedStatement的优点:

Precompilation and DB-side caching of the SQL statement leads to overall faster execution and the ability to reuse the same SQL statement in batches. Automatic prevention of SQL injection attacks by builtin escaping of quotes and other special characters. Note that this requires that you use any of the PreparedStatement setXxx() methods to set the values preparedStatement = connection.prepareStatement("INSERT INTO Person (name, email, birthdate, photo) VALUES (?, ?, ?, ?)"); preparedStatement.setString(1, person.getName()); preparedStatement.setString(2, person.getEmail()); preparedStatement.setTimestamp(3, new Timestamp(person.getBirthdate().getTime())); preparedStatement.setBinaryStream(4, person.getPhoto()); preparedStatement.executeUpdate(); and thus don't inline the values in the SQL string by string-concatenating. preparedStatement = connection.prepareStatement("INSERT INTO Person (name, email) VALUES ('" + person.getName() + "', '" + person.getEmail() + "'"); preparedStatement.executeUpdate(); Eases setting of non-standard Java objects in a SQL string, e.g. Date, Time, Timestamp, BigDecimal, InputStream (Blob) and Reader (Clob). On most of those types you can't "just" do a toString() as you would do in a simple Statement. You could even refactor it all to using PreparedStatement#setObject() inside a loop as demonstrated in the utility method below: public static void setValues(PreparedStatement preparedStatement, Object... values) throws SQLException { for (int i = 0; i < values.length; i++) { preparedStatement.setObject(i + 1, values[i]); } } Which can be used as below: preparedStatement = connection.prepareStatement("INSERT INTO Person (name, email, birthdate, photo) VALUES (?, ?, ?, ?)"); setValues(preparedStatement, person.getName(), person.getEmail(), new Timestamp(person.getBirthdate().getTime()), person.getPhoto()); preparedStatement.executeUpdate();

2010-07-17 21:37:07

其他回答

语句是静态的，准备语句是动态的。

Statement适用于DDL, prepared Statement适用于DML。

语句较慢，而准备语句较快。

更多差异(存档)

2013-11-27 10:41:17

PreparedStatement是一种非常好的防御(但不是万无一失的)，可以防止SQL注入攻击。绑定参数值是防止“小Bobby表”进行不必要访问的好方法。

2010-07-17 12:05:09

这样更容易阅读您可以轻松地将查询字符串设置为常量

2010-09-13 13:01:15

不能在语句中使用clob。