1.JDBC总结(模板)
a. 导入驱动包、加载具体的驱动类 Class.forName(“具体驱动类”);
b. 与数据库建立连接 connection = DriverManager.getConnection(…);
c. 通过connection,获取操作数据库的对象 (Statement\preparedStatement\callablestatement)
stmt = connection.createStatement();
d. (查询) 处理结果集 rs = pstmt.executeQuery()
while(rs,next()){ rs.getXxx(…); }
}catch(ClassNotFoundException e)
{ . . . . .
}
catch( SQLException e)
{ . . … . .
}catch( Exception e)
{ . . … . .
}finally
{ . .关闭资源 , 与打开顺序相反
rs.close();
if(stmt != null) stmt.close();
connection.close();
}
–JDBC中,除了Class.forName() 抛出ClassNotFoundException, 其余方法全部抛SQLException .
package NetSql;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class NetMysql001 {
private static String driver="com.mysql.jdbc.Driver";//驱动程序类
private static String url="jdbc:mysql://localhost:3306/StudentScore?characterEncoding=utf8";
private static String user="root";
private static String password="ren372930";
public static void main(String[] args) {
try {
//a. 导入驱动,加载具体的驱动类
Class.forName(driver);
System.out.println("注册驱动成功!");
} catch (Exception e1) {
// TODO: handle exception
System.out.println("注册驱动失败!");
e1.printStackTrace();
return;
}
String sql = "SELECT sNo,sName,sex,age FROM Student WHERE dept = '计算机'";
try (
//b. 与数据库建立连接
Connection conn = DriverManager.getConnection(url,user, password);
//c. 发送sql,执行(增删改 查)
Statement stmt = conn.createStatement();
// 执行查询操作 用executeQuery();
ResultSet rs = stmt.executeQuery(sql);
){
while(rs.next()) {
String no = rs.getString("sNo");
String name = rs.getString("sName");
String sex = rs.getString("sex");
int age = rs.getInt("age");
System.out.println(no+" "+name+" "+sex+" "+age);
}
}
catch (Exception e) {
e.printStackTrace();
}
}
}
package NetSql;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class NetMysql002 {
private static String driver = "com.mysql.jdbc.Driver";
private static String url = "jdbc:mysql://localhost:3306/StudentScore?useSSL=false";
private static String user = "root";
private static String password = "ren372930";
public NetMysql002() {
}
public static void main(String[] args) {
String selectSql = "SELECT * FROM Student WHERE dept='计算机'";
String insertSql = "INSERT INTO Student(sNo,sName,sex,age,dept) VALUES('201201009','王毅','男','18','外语');";
String updateSql = "UPDATE Student SET dept='金融' WHERE sNo='201201009'";
String deleteSql = "DELETE FROM Student WHERE sNo='201201009'";
try {
Throwable var5 = null;
Object var6 = null;
try {
Connection conn = DriverManager.getConnection(url, user, password);
try {
Statement stmt = conn.createStatement();
try {
ResultSet rs = stmt.executeQuery(selectSql);
try {
Class.forName(driver);
while(rs.next()) {
String no = rs.getString("sNo");
String name = rs.getString("sName");
String sex = rs.getString("sex");
int age = rs.getInt("age");
String dept = rs.getString("dept");
System.out.println(no + " " + name + " " + sex + " " + age + " " + dept);
}
int count = stmt.executeUpdate(insertSql);
System.out.println("添加" + count + "条记录到Student表中");
count = stmt.executeUpdate(updateSql);
System.out.println("修改了Student表的" + count + "条记录");
count = stmt.executeUpdate(deleteSql);
System.out.println("删除了Student表的" + count + "条记录");
} finally {
if (rs != null) {
rs.close();
}
}
} catch (Throwable var36) {
if (var5 == null) {
var5 = var36;
} else if (var5 != var36) {
var5.addSuppressed(var36);
}
if (stmt != null) {
stmt.close();
}
throw var5;
}
if (stmt != null) {
stmt.close();
}
} catch (Throwable var37) {
if (var5 == null) {
var5 = var37;
} else if (var5 != var37) {
var5.addSuppressed(var37);
}
if (conn != null) {
conn.close();
}
throw var5;
}
if (conn != null) {
conn.close();
}
} catch (Throwable var38) {
if (var5 == null) {
var5 = var38;
} else if (var5 != var38) {
var5.addSuppressed(var38);
}
throw var5;
}
} catch (Exception var39) {
var39.printStackTrace();
}
}
}
package NetSql;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class NetMysql003 {
private static String driver = "com.mysql.jdbc.Driver";
private static String url = "jdbc:mysql://localhost/StudentScore?useSSL=false";
private static String user = "root";
private static String password = "ren372930";
public NetMysql003() {
}
public static void main(String[] args) {
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
String selectSql = "SELECT * FROM Student WHERE dept=?";
String insertSql = "INSERT INTO Student(sNo,sName,sex,age,dept)VALUES(?,?,?,?,?);";
String updateSql = "UPDATE Student SET dept='金融' WHERE sNo=?";
String deleteSql = "DELETE FROM Student WHERE sNo=?";
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, user, password);
ps = conn.prepareStatement(selectSql);
ps.setString(1, "计算机");
rs = ps.executeQuery();
while(rs.next()) {
String no = rs.getString("sNo");
String name = rs.getString("sName");
String sex = rs.getString("sex");
int age = rs.getInt("age");
String dept = rs.getString("dept");
System.out.println(no + " " + name + " " + sex + " " + age + " " + dept);
}
ps = conn.prepareStatement(insertSql);
ps.setString(1, "201201009");
ps.setString(2, "王毅");
ps.setString(3, "男");
ps.setInt(4, 18);
ps.setString(5, "外语");
int count = ps.executeUpdate();
System.out.println("添加" + count + "条记录到Student表中");
ps = conn.prepareStatement(updateSql);
ps.setString(1, "201201009");
count = ps.executeUpdate();
System.out.println("修改了Student表的" + count + "条记录");
ps = conn.prepareStatement(deleteSql);
ps.setString(1, "201201009");
count = ps.executeUpdate();
System.out.println("删除了Student表的" + count + "条记录");
} catch (Exception var21) {
var21.printStackTrace();
} finally {
try {
if (rs != null) {
rs.close();
}
if (ps != null) {
ps.close();
}
if (conn != null) {
conn.close();
}
} catch (Exception var20) {
var20.printStackTrace();
}
}
}
}