由数据库对sql的执行说JDBC的Statement和PreparedStatement
/** * PreparedStatement是在创建pstm的时候就给它传一个动态的sql，参数是通过pstm设置的。执行时，只需要空执行一下就可以.* @author Administrator
*
*/
public> /**
* 操作表jdbc_users
* @param args
*/
public static void main(String[] args) {
User u=new User();
u.setId(21);
u.setName("statement");
u.setPasswd("yf123");
u.setPhone("13821930");
u.setEmail("yf@163.com");
//insert(u);
//delete(42);
//reset(u);
System.out.println(getById(21));
}
/**增*/
public static void insert(User user){
Connection conn=null;
PreparedStatement pstmt=null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
//conn=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:ORCL10","scott","yf123");
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:ORCL10", "SCOTT", "yf123");
String sql="insert into jdbc_users values(?,?,?,?,?)";
pstmt=conn.prepareStatement(sql);//PreparedStatement创建时就传过去一个sql语句,这样就可以预编译
/**然后设置sql中好占位符的值,这里是动态的传参数*/
pstmt.setInt(1, user.getId());
pstmt.setString(2, user.getName());
pstmt.setString(3, user.getPasswd());
pstmt.setString(4, user.getPhone());
pstmt.setString(5, user.getEmail());
/**设置好后，就全封装到pstm里了,只要空执行就可以了*/
pstmt.execute();
} catch (Exception e) {
e.printStackTrace();
}finally{
if(pstmt!=null){try{pstmt.close();}catch(Exception e){}}
if(conn!=null){try{conn.close();}catch(Exception e){}}
}
}
/**删*/
public static void delete(Integer> Connection conn=null;
PreparedStatement pstmt=null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
//conn=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:ORCL10","scott","yf123");
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:ORCL10", "SCOTT", "yf123");
String sql="delete from jdbc_users where> /**PreparedStatement创建时就传过去一个sql语句,这样就可以预编译*/
pstmt=conn.prepareStatement(sql);
/**然后设置sql中好占位符的值,这里是动态的传参数*/
pstmt.setInt(1,> /**设置好后，就全封装到pstm里了,只要空执行就可以了*/
pstmt.execute();
} catch (Exception e) {
e.printStackTrace();
}finally{
if(pstmt!=null){try{pstmt.close();}catch(Exception e){}}
if(conn!=null){try{conn.close();}catch(Exception e){}}
}
}
/**改*/
public static void reset(User u){
Connection conn=null;
PreparedStatement pstmt=null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
//conn=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:ORCL10","scott","yf123");
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:ORCL10", "SCOTT", "yf123");
String sql="update jdbc_users set name=?,passwd=?,phone=?,email=? where> /**PreparedStatement创建时就传过去一个sql语句,这样就可以预编译*/
pstmt=conn.prepareStatement(sql);
/**然后设置sql中好占位符的值,这里是动态的传参数*/
pstmt.setString(1, u.getName());
pstmt.setString(2, u.getPasswd());
pstmt.setString(3, u.getPhone());
pstmt.setString(4, u.getEmail());
pstmt.setInt(5, u.getId());
/**设置好后，就全封装到pstm里了,只要空执行就可以了*/
pstmt.execute();
} catch (Exception e) {
e.printStackTrace();
}finally{
if(pstmt!=null){try{pstmt.close();}catch(Exception e){}}
if(conn!=null){try{conn.close();}catch(Exception e){}}
}
}
/**查*/
public static User getById(Integer> Connection conn=null;
PreparedStatement pstmt=null;
ResultSet rs=null;
User u=null;
try {
Class.forName("oracle.jdbc.driver.OracleDriver");
//conn=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:ORCL10","scott","yf123");
conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:ORCL10", "SCOTT", "yf123");
String sql="select * from jdbc_users where> pstmt=conn.prepareStatement(sql);//Statement创建时就是一个空的执行器
/**在execute或者executeQuery时执行死的sql语句*/
/**这只能是拼好的字符串,而不能动态的传参数,并且在数据库中每次肯定穿的是不同的sql语句，因此每次都要解析编译*/
pstmt.setInt(1,> rs=pstmt.executeQuery();
while(rs.next()){
u=new User();
u.setId(rs.getInt("id"));
u.setName(rs.getString("name"));
u.setPhone(rs.getString("phone"));
u.setPasswd(rs.getString("passwd"));
u.setEmail(rs.getString("email"));
}
} catch (Exception e) {
e.printStackTrace();
}finally{
if(pstmt!=null){try{pstmt.close();}catch(Exception e){}}
if(conn!=null){try{conn.close();}catch(Exception e){}}
}
return u;
}
}
页:
[1]