Java数据库增删改查

时间:2023-02-27 20:09:20

数据库为MySQL数据库,Oracle数据库类似:

表结构参照

插入数据

package com.jef.sql;

import java.sql.Connection;
import java.sql.PreparedStatement; /**
* //演示如何使用com.mysql.jdbc连接桥连接Mysql,插入内容,共三种方式:静态的两种executeUpdate(),executeBatch(),动态的PrepareStatement,
* 实时动态时可以采用PrepareStatement()和executeBatch()的结合,删除、修改都有这三种方法
*/
public class JavaCtMysqlInsert {
public static void main(String[] args) {
try {
Connection ct = ConnectionMySQL.getMySQLConnection();
ct.setAutoCommit(false);
PreparedStatement ps = ct.prepareStatement("insert into user values(?, ?)");
ps.setString(1, "ranye");
ps.setString(2, "100");
ps.executeUpdate();
ps.clearParameters();
ct.commit();
ct.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
package com.jef.sql;

import java.sql.Connection;
import java.sql.Statement; public class JavaCtMysqlInsertTwo {
public static void main(String[] args) {
try {
Connection ct = ConnectionMySQL.getMySQLConnection();
ct.setAutoCommit(false);
Statement sm = ct.createStatement();
sm.addBatch("insert into user values('dage', 100)");
sm.addBatch("insert into user values('haonan', 100)");
sm.executeBatch();
ct.commit();
sm.close();
ct.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
package com.jef.sql;

import java.sql.Connection;
import java.sql.Statement; public class JavaCtMysqlInsertThree {
public static void main(String[] args) {
try {
Connection ct = ConnectionMySQL.getMySQLConnection();
ct.setAutoCommit(false);
Statement sm = ct.createStatement();
sm.executeUpdate("insert into user values('yuanyuan', '100')");
ct.commit();
sm.close();
ct.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}

删除数据

package com.jef.sql;

import java.sql.Connection;
import java.sql.Statement; public class JavaCtMysqlDelete {
public static void main(String[] args) {
try {
Connection ct = ConnectionMySQL.getMySQLConnection();
Statement sm = ct.createStatement();
sm.executeUpdate("delete from user where name='tufujie'");
sm.close();
ct.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
package com.jef.sql;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement; public class JavaCtMysqlDeleteTwo {
public static void main(String[] args) {
try {
Connection ct = ConnectionMySQL.getMySQLConnection();
Statement sm = ct.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
ResultSet rs = sm.executeQuery("select * from user where name='dage'");// 从查询到的内容中进行修改、插入和删除
rs.last();
rs.deleteRow();
rs.close();
sm.close();
ct.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}

修改数据

package com.jef.sql;

import java.sql.Connection;
import java.sql.Statement; public class JavaCtMysqlUpdate {
public static void main(String[] args) {
try {
Connection ct = ConnectionMySQL.getMySQLConnection();
Statement sm = ct.createStatement();
sm.executeUpdate("update user set name='ran' where name='ranye'");
sm.close();
ct.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}

查询数据

package com.jef.sql;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement; /**
* 当前情况下至少需要4+2条数据存在,特殊场景需捕获或者抛出
*/
public class JavaCtMysqlSelect {
public static void main(String[] args) {
try {
Connection conn = ConnectionMySQL.getMySQLConnection();
Statement stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
ResultSet.CONCUR_READ_ONLY);
ResultSet result = stmt.executeQuery("select * from user");
System.out.println("从末尾数据开始输出");
result.last();
System.out.println(result.getString("name") + "\t" + result.getString("password"));
while (result.previous())
System.out.println(result.getString("name") + "\t" + result.getString("password"));
System.out.println("从起始数据开始输出");
result.first();
System.out.println(result.getString("name") + "\t" + result.getString("password"));
while(result.next())
System.out.println(result.getString("name") + "\t" + result.getString("password")); // 指定第几笔数据
System.out.println("指定第几笔数据,这里指定第4笔数据");
result.absolute(4);
System.out.println(result.getString("name") + "\t" + result.getString("password")); // 从目前游标处指定游标下移数
System.out.println("从目前游标处指定游标位置,这里向下移动2笔数据");
result.relative(2);
System.out.println(result.getString("name") + "\t" + result.getString("password"));
result.close();
stmt.close();
conn.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}