准备语句忽略SQL注入，提高了准备语句的安全性

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。

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)

PreparedStatement相对于Statement的一些好处是:

PreparedStatement helps us in preventing SQL injection attacks because it automatically escapes the special characters. PreparedStatement allows us to execute dynamic queries with parameter inputs. PreparedStatement provides different types of setter methods to set the input parameters for the query. PreparedStatement is faster than Statement. It becomes more visible when we reuse the PreparedStatement or use it’s batch processing methods for executing multiple queries. PreparedStatement helps us in writing object Oriented code with setter methods whereas with Statement we have to use String Concatenation to create the query. If there are multiple parameters to set, writing Query using String concatenation looks very ugly and error prone.

阅读更多关于SQL注入问题，请访问http://www.journaldev.com/2489/jdbc-statement-vs-preparedstatement-sql-injection-example

不能在语句中使用clob。

And: (OraclePreparedStatement) ps

They are pre-compiled (once), so faster for repeated execution of dynamic SQL (where parameters change) Database statement caching boosts DB execution performance Databases store caches of execution plans for previously executed statements. This allows the database engine to reuse the plans for statements that have been executed previously. Because PreparedStatement uses parameters, each time it is executed it appears as the same SQL, the database can reuse the previous access plan, reducing processing. Statements "inline" the parameters into the SQL string and so do not appear as the same SQL to the DB, preventing cache usage. Binary communications protocol means less bandwidth and faster comms calls to DB server Prepared statements are normally executed through a non-SQL binary protocol. This means that there is less data in the packets, so communications to the server is faster. As a rule of thumb network operations are an order of magnitude slower than disk operations which are an order of magnitude slower than in-memory CPU operations. Hence, any reduction in amount of data sent over the network will have a good effect on overall performance. They protect against SQL injection, by escaping text for all the parameter values provided. They provide stronger separation between the query code and the parameter values (compared to concatenated SQL strings), boosting readability and helping code maintainers quickly understand inputs and outputs of the query. In java, can call getMetadata() and getParameterMetadata() to reflect on the result set fields and the parameter fields, respectively In java, intelligently accepts java objects as parameter types via setObject, setBoolean, setByte, setDate, setDouble, setDouble, setFloat, setInt, setLong, setShort, setTime, setTimestamp - it converts into JDBC type format that is comprehendible to DB (not just toString() format). In java, accepts SQL ARRAYs, as parameter type via setArray method In java, accepts CLOBs, BLOBs, OutputStreams and Readers as parameter "feeds" via setClob/setNClob, setBlob, setBinaryStream, setCharacterStream/setAsciiStream/setNCharacterStream methods, respectively In java, allows DB-specific values to be set for SQL DATALINK, SQL ROWID, SQL XML, and NULL via setURL, setRowId, setSQLXML ans setNull methods In java, inherits all methods from Statement. It inherits the addBatch method, and additionally allows a set of parameter values to be added to match the set of batched SQL commands via addBatch method. In java, a special type of PreparedStatement (the subclass CallableStatement) allows stored procedures to be executed - supporting high performance, encapsulation, procedural programming and SQL, DB administration/maintenance/tweaking of logic, and use of proprietary DB logic & features