JDBC的CRUD操作：
插入操作：
public class JDBC_Demo_bao_cun {
@Test
/**
* 保存操作
*/
public void demo(){
Connection conn = null;
Statement statement = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql:///jdbctest","root", "wxhxx520");
statement = conn.createStatement();
String sql = "insert goods values(null, 'eee', 123,'hahaha')";
int i = statement.executeUpdate(sql);
if (i > 0) {
System.out.println("保存成功");
} else {
System.out.println("保存失败");
}
} catch (Exception e){
e.printStackTrace();
} finally {
if (statement != null) {
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
statement = null;
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
}
}
更新操作：
public void demo2(){
Connection conn = null;
Statement statement = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql:///jdbctest","root", "wxhxx520");
statement = conn.createStatement();
String sql = "update goods set name='悠悠球', price=299,desp='好玩！！!' where id = 5";
int i = statement.executeUpdate(sql);
if (i > 0) {
System.out.println("修改成功");
} else {
System.out.println("修改失败");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (statement != null) {
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
statement = null;
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
}
删除操作：
public void demo3(){
Connection conn = null;
Statement statement = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql:///jdbctest","root", "wxhxx520");
statement =conn.createStatement();
String sql = "delete from goods where id=5";
int i = statement.executeUpdate(sql);
if (i > 0) {
System.out.println("删除成功");
} else {
System.out.println("删除失败");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (statement != null) {
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
statement = null;
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
}
查询操作：
public void demo4(){
Connection conn = null;
Statement statement = null;
ResultSet resultSet = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql:///jdbctest","root", "wxhxx520");
statement = conn.createStatement();
String sql = "select * from goods";
resultSet = statement.executeQuery(sql);
while (resultSet.next()) {
int id =resultSet.getInt("id");
String name =resultSet.getString("name");
float price =resultSet.getFloat("price");
String desp =resultSet.getString("desp");
System.out.println(id +" " + name + " " + price + " " + desp);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException e) {
e.printStackTrace();
}
resultSet = null;
}
if (statement != null) {
try {
statement.close();
} catch (SQLException e){
e.printStackTrace();
}
statement = null;
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
}