JDBC增刪改查例項
阿新 • • 發佈：2019-02-11
//增
public boolean insert(Users entity) {
//宣告返回值變數
boolean flag = false;
//獲取連線物件
conn = JdbcUtil.getConn();
//定義sql語句
String sql = "insert into users(id,name,pass,sex,age) values(?,?,?,?,?)";
try {
//根據sql語句建立預處理物件
pstmt = conn.prepareStatement(sql);
//為佔位符賦值
int index = 1;
pstmt.setObject(index++, entity.getId());
pstmt.setObject(index++, entity.getName());
pstmt.setObject(index++, entity.getPass());
pstmt.setObject(index++, entity.getSex());
pstmt.setObject(index++, entity.getAge());
//執行更新
int i = pstmt.executeUpdate();
if(i>0){
flag = true;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//釋放資源
JdbcUtil.release(rs, pstmt);
return flag;
}
//刪
public boolean deleteById(Integer id) {
//宣告返回值變數
boolean flag = false;
//獲取連線物件
conn = JdbcUtil.getConn();
//定義sql語句
String sql = "delete from users where id=?";
try {
//根據sql語句建立預處理物件
pstmt = conn.prepareStatement(sql);
//為佔位符賦值
int index = 1;
pstmt.setObject(index++, id);
//執行更新
int i = pstmt.executeUpdate();
if(i>0){
flag = true;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//釋放資源
JdbcUtil.release(rs, pstmt);
return flag;
}
//改
public boolean updateById(Users entity) {
//宣告返回值變數
boolean flag = false;
//獲取連線物件
conn = JdbcUtil.getConn();
//定義sql語句
String sql = "update users set name=?,pass=?,sex=?,age=? where id=?";
try {
//根據sql語句建立預處理物件
pstmt = conn.prepareStatement(sql);
//為佔位符賦值
int index = 1;
pstmt.setObject(index++, entity.getName());
pstmt.setObject(index++, entity.getPass());
pstmt.setObject(index++, entity.getSex());
pstmt.setObject(index++, entity.getAge());
pstmt.setObject(index++, entity.getId());
//執行更新
int i = pstmt.executeUpdate();
if(i>0){
flag = true;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//釋放資源
JdbcUtil.release(rs, pstmt);
return flag;
}
//查
public Users findById(Integer id) {
//宣告返回值變數
Users entity = new Users();
//獲取連線物件
conn = JdbcUtil.getConn();
//定義sql語句
String sql = "select * from users where id=?";
try {
//根據sql語句建立預處理物件
pstmt = conn.prepareStatement(sql);
//為佔位符賦值
int index = 1;
pstmt.setObject(index++, id);
//執行更新
rs = pstmt.executeQuery();
if(rs.next()){
entity.setId(rs.getInt("id"));
entity.setName(rs.getString("name"));
entity.setPass(rs.getString("pass"));
entity.setSex(rs.getString("sex"));
entity.setAge(rs.getInt("age"));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//釋放資源
JdbcUtil.release(rs, pstmt);
return entity;
}
}
public boolean insert(Users entity) {
//宣告返回值變數
boolean flag = false;
//獲取連線物件
conn = JdbcUtil.getConn();
//定義sql語句
String sql = "insert into users(id,name,pass,sex,age) values(?,?,?,?,?)";
try {
//根據sql語句建立預處理物件
pstmt = conn.prepareStatement(sql);
//為佔位符賦值
int index = 1;
pstmt.setObject(index++, entity.getId());
pstmt.setObject(index++, entity.getName());
pstmt.setObject(index++, entity.getPass());
pstmt.setObject(index++, entity.getSex());
pstmt.setObject(index++, entity.getAge());
//執行更新
int i = pstmt.executeUpdate();
if(i>0){
flag = true;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//釋放資源
JdbcUtil.release(rs, pstmt);
return flag;
}
//刪
public boolean deleteById(Integer id) {
//宣告返回值變數
boolean flag = false;
//獲取連線物件
conn = JdbcUtil.getConn();
//定義sql語句
String sql = "delete from users where id=?";
try {
//根據sql語句建立預處理物件
pstmt = conn.prepareStatement(sql);
//為佔位符賦值
int index = 1;
pstmt.setObject(index++, id);
//執行更新
int i = pstmt.executeUpdate();
if(i>0){
flag = true;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//釋放資源
JdbcUtil.release(rs, pstmt);
return flag;
}
//改
public boolean updateById(Users entity) {
//宣告返回值變數
boolean flag = false;
//獲取連線物件
conn = JdbcUtil.getConn();
//定義sql語句
String sql = "update users set name=?,pass=?,sex=?,age=? where id=?";
try {
//根據sql語句建立預處理物件
pstmt = conn.prepareStatement(sql);
//為佔位符賦值
int index = 1;
pstmt.setObject(index++, entity.getName());
pstmt.setObject(index++, entity.getPass());
pstmt.setObject(index++, entity.getSex());
pstmt.setObject(index++, entity.getAge());
pstmt.setObject(index++, entity.getId());
//執行更新
int i = pstmt.executeUpdate();
if(i>0){
flag = true;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//釋放資源
JdbcUtil.release(rs, pstmt);
return flag;
}
//查
public Users findById(Integer id) {
//宣告返回值變數
Users entity = new Users();
//獲取連線物件
conn = JdbcUtil.getConn();
//定義sql語句
String sql = "select * from users where id=?";
try {
//根據sql語句建立預處理物件
pstmt = conn.prepareStatement(sql);
//為佔位符賦值
int index = 1;
pstmt.setObject(index++, id);
//執行更新
rs = pstmt.executeQuery();
if(rs.next()){
entity.setId(rs.getInt("id"));
entity.setName(rs.getString("name"));
entity.setPass(rs.getString("pass"));
entity.setSex(rs.getString("sex"));
entity.setAge(rs.getInt("age"));
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//釋放資源
JdbcUtil.release(rs, pstmt);
return entity;
}
}