JDBC之Statement与preparedStatement

用Statement执行数据库语句比较麻烦。

例如，向数据库中插入整型， 字符串等数据。

 1 String JDriver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";

 2         String connectDB="jdbc:sqlserver://ABYSS-

 3                 PC\\MYABYSS:64160;DatabaseName=master";

 4         //实例化驱动

 5         Class.forName(JDriver);

 6         String user ="sa";

 7         String possword = "";

 8         //连接数据库

 9         Connection conn = 

10 DriverManager.getConnection(connectDB, user, possword);

11         //创建语句对象

12         Statement stmt = conn.createStatement();

13         int Number = 189;

14         String City = "北京";

15         String Job = "服务业";

16         String sql = "insert into dept2 values (" +

17                      Number+",'" + City +"','"+ Job+"')";

18         stmt.executeUpdate(sql);

在sql变量中又是单引号 又是逗号的很麻烦，而且一不小心容易写错。

换成preparedStatement就简单许多了

 1         String JDriver = "com.microsoft.sqlserver.jdbc.SQLServerDriver";

 2         String connectDB="jdbc:sqlserver://ABYSS-

 3 PC\\MYABYSS:64160;DatabaseName=master";

 4         //实例化驱动

 5         Class.forName(JDriver);

 6         String user ="sa";

 7         String possword = "";

 8         //连接数据库

 9         Connection conn = 

10 DriverManager.getConnection(connectDB, user, possword);

11         //创建语句对象

12         int Number = 189;

13         String City = "北京";

14         String Job = "服务业";

15         PreparedStatement pstmt =

16         conn.prepareStatement( "insert into dept2 values (?, ?, ?)");

17         pstmt.setInt(1, Number);

18         pstmt.setString(2, City);

19         pstmt.setString(3, Job);

20         pstmt.executeUpdate();