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();
其他回答
语句接口执行不带参数的静态SQL语句
PreparedStatement接口(扩展Statement)执行预编译的带/不带参数的SQL语句
对于重复执行有效 它是预编译的，所以更快
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();
没什么可补充的，
1 -如果你想在循环中执行查询(超过1次)，由于你提到的优化，预处理语句可以更快。
2 .参数化查询是避免SQL注入的好方法。参数化查询只在PreparedStatement中可用。
语句将用于执行静态SQL语句，它不能接受输入参数。
PreparedStatement将用于多次动态执行SQL语句。它将接受输入参数。
不能在语句中使用clob。
And: (OraclePreparedStatement) ps
