mysql併發安全問題的思考(避免併發插入時出現相同的用戶名之unique 索引的使用)

原創 弄懂原理+良好代码功底=无敌 2020-05-11 11:34 
package cn.itcast.jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

public class JdbcDemo02_Insert {

    public void f() {
        Statement stmt = null;
        Connection conn = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            for (int i = 0; i < 10; i++) {
                String name = "嗷嗷啊";
                String sql = "insert into account values(null, '" + name + i + "', 3000)";
                System.out.println(sql);
                conn = DriverManager.getConnection("jdbc:mysql:///db3", "root", "jianan");
                stmt = conn.createStatement();
                int count = stmt.executeUpdate(sql);
                System.out.println(count);
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (stmt != null) {
                try {
                    stmt.close();
                    stmt = null;
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }

            if (conn != null) {
                try {
                    conn.close();
                    conn = null;
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }

    public static void main(String[] args) {
        new Thread(() -> {
            new JdbcDemo02_Insert().f();
        }).start();

        new Thread(() -> {
            new JdbcDemo02_Insert().f();
        }).start();

        new Thread(() -> {
            new JdbcDemo02_Insert().f();
        }).start();

        new Thread(() -> {
            new JdbcDemo02_Insert().f();
        }).start();

        new Thread(() -> {
            new JdbcDemo02_Insert().f();
        }).start();

        new Thread(() -> {
            new JdbcDemo02_Insert().f();
        }).start();

        new Thread(() -> {
            new JdbcDemo02_Insert().f();
        }).start();
    }
}

輸出

insert into account values(null, '嗷嗷啊0', 3000)
insert into account values(null, '嗷嗷啊0', 3000)
insert into account values(null, '嗷嗷啊0', 3000)
insert into account values(null, '嗷嗷啊0', 3000)
insert into account values(null, '嗷嗷啊0', 3000)
insert into account values(null, '嗷嗷啊0', 3000)
insert into account values(null, '嗷嗷啊0', 3000)
1
insert into account values(null, '嗷嗷啊1', 3000)
1
insert into account values(null, '嗷嗷啊2', 3000)
1
insert into account values(null, '嗷嗷啊3', 3000)
1
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '嗷嗷啊0' for key 'name'
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
	at com.mysql.jdbc.Util.getInstance(Util.java:387)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:934)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3870)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3806)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2470)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2617)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2546)
	at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1541)
	at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2605)
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1469)
	at cn.itcast.jdbc.JdbcDemo02_Insert.f(JdbcDemo02_Insert.java:21)
	at cn.itcast.jdbc.JdbcDemo02_Insert.lambda$main$6(JdbcDemo02_Insert.java:74)
	at java.lang.Thread.run(Thread.java:748)
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '嗷嗷啊0' for key 'name'
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
	at com.mysql.jdbc.Util.getInstance(Util.java:387)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:934)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3870)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3806)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2470)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2617)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2546)
	at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1541)
	at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2605)
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1469)
	at cn.itcast.jdbc.JdbcDemo02_Insert.f(JdbcDemo02_Insert.java:21)
	at cn.itcast.jdbc.JdbcDemo02_Insert.lambda$main$1(JdbcDemo02_Insert.java:54)
	at java.lang.Thread.run(Thread.java:748)
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '嗷嗷啊0' for key 'name'
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
	at com.mysql.jdbc.Util.getInstance(Util.java:387)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:934)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3870)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3806)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2470)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2617)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2546)
	at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1541)
	at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2605)
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1469)
	at cn.itcast.jdbc.JdbcDemo02_Insert.f(JdbcDemo02_Insert.java:21)
	at cn.itcast.jdbc.JdbcDemo02_Insert.lambda$main$4(JdbcDemo02_Insert.java:66)
	at java.lang.Thread.run(Thread.java:748)
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '嗷嗷啊0' for key 'name'
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
	at com.mysql.jdbc.Util.getInstance(Util.java:387)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:934)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3870)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3806)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2470)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2617)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2546)
	at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1541)
	at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2605)
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1469)
	at cn.itcast.jdbc.JdbcDemo02_Insert.f(JdbcDemo02_Insert.java:21)
	at cn.itcast.jdbc.JdbcDemo02_Insert.lambda$main$3(JdbcDemo02_Insert.java:62)
	at java.lang.Thread.run(Thread.java:748)
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '嗷嗷啊0' for key 'name'
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
	at com.mysql.jdbc.Util.getInstance(Util.java:387)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:934)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3870)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3806)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2470)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2617)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2546)
	at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1541)
	at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2605)
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1469)
	at cn.itcast.jdbc.JdbcDemo02_Insert.f(JdbcDemo02_Insert.java:21)
	at cn.itcast.jdbc.JdbcDemo02_Insert.lambda$main$2(JdbcDemo02_Insert.java:58)
	at java.lang.Thread.run(Thread.java:748)
com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '嗷嗷啊0' for key 'name'
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:404)
	at com.mysql.jdbc.Util.getInstance(Util.java:387)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:934)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3870)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3806)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2470)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2617)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2546)
	at com.mysql.jdbc.StatementImpl.executeUpdateInternal(StatementImpl.java:1541)
	at com.mysql.jdbc.StatementImpl.executeLargeUpdate(StatementImpl.java:2605)
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1469)
	at cn.itcast.jdbc.JdbcDemo02_Insert.f(JdbcDemo02_Insert.java:21)
	at cn.itcast.jdbc.JdbcDemo02_Insert.lambda$main$5(JdbcDemo02_Insert.java:70)
	at java.lang.Thread.run(Thread.java:748)
insert into account values(null, '嗷嗷啊4', 3000)
1
insert into account values(null, '嗷嗷啊5', 3000)
1
insert into account values(null, '嗷嗷啊6', 3000)
1
insert into account values(null, '嗷嗷啊7', 3000)
1
insert into account values(null, '嗷嗷啊8', 3000)
1
insert into account values(null, '嗷嗷啊9', 3000)
1

實際插入結果: 可見併發插入的情況下，由於mysql設置了name爲唯一，最終是正確的。

unique索引如下

 

 

總結： 可見jdbc還是比較給力的。 自己簡單封裝下即可，遊戲業務中不需要用複雜的mybatis，造成框架的複雜性減少黑盒！

簡單的代碼就實現：

1.事務

2.數據庫CURD基本操作

發表評論
所有評論
還沒有人評論，想成為第一個評論的人麼? 請在上方評論欄輸入並且點擊發布.
相關文章

能防止sql注入的 效率更高的 PreparedStatement

弄懂原理+良好代码功底=无敌 2020-05-12 19:41:53

mysql連接池druid + jedis連接池JedisPool 實現 “mysql+redis”終極操作數據庫

弄懂原理+良好代码功底=无敌 2020-05-12 19:41:53

druid連接池工具類的使用

弄懂原理+良好代码功底=无敌 2020-05-12 19:41:53

jdbc控制事務~以轉賬出異常時，2個人的賬戶正常

弄懂原理+良好代码功底=无敌 2020-05-12 19:41:53

用類加載器加載resources目錄下的jdbc.properties文件(支持打成jar包後路徑依然支持)

弄懂原理+良好代码功底=无敌 2020-05-11 11:34:28

JDBC規範中5個類DriverManager、Connection、Statement、ResultSet、PreparedStatement的介紹

弄懂原理+良好代码功底=无敌 2020-05-10 21:07:06

jdbc快速入門

弄懂原理+良好代码功底=无敌 2020-05-10 09:43:09

SpringJDBC中DataSource的實現

maven依賴： <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <v

chenjazz 2020-07-01 11:08:43

能防止sql注入的 效率更高的 PreparedStatement

弄懂原理+良好代码功底=无敌 2020-05-12 19:41:53

mysql連接池druid + jedis連接池JedisPool 實現 “mysql+redis”終極操作數據庫

弄懂原理+良好代码功底=无敌 2020-05-12 19:41:53

druid連接池工具類的使用

弄懂原理+良好代码功底=无敌 2020-05-12 19:41:53

jdbc控制事務~以轉賬出異常時，2個人的賬戶正常

弄懂原理+良好代码功底=无敌 2020-05-12 19:41:53

用類加載器加載resources目錄下的jdbc.properties文件(支持打成jar包後路徑依然支持)

弄懂原理+良好代码功底=无敌 2020-05-11 11:34:28

JDBC規範中5個類DriverManager、Connection、Statement、ResultSet、PreparedStatement的介紹

弄懂原理+良好代码功底=无敌 2020-05-10 21:07:06

jdbc快速入門

弄懂原理+良好代码功底=无敌 2020-05-10 09:43:09