使用limit分页查询时,做delete操作,会导致丢失数据

目录

一、准备数据

1.1 mysql数据脚本

set names utf8mb4;
set foreign_key_checks = 0;

-- ----------------------------
-- table structure for test_so_item
-- ----------------------------
drop table if exists `test_so_item`;
create table `test_so_item`  (
  `id` bigint(20) not null auto_increment,
  `line_no` varchar(20) character set utf8mb4 collate utf8mb4_general_ci null default null,
  `sku` varchar(255) character set utf8mb4 collate utf8mb4_general_ci null default null,
  `qty` decimal(4, 2) null default null,
  primary key (`id`) using btree
) engine = innodb auto_increment = 1 character set = utf8mb4 collate = utf8mb4_general_ci row_format = dynamic;

-- ----------------------------
-- records of test_so_item
-- ----------------------------
insert into `test_so_item` values (1, '00020', 'a0001', 10.00);
insert into `test_so_item` values (2, '00010', 'nt9531', 1.00);
insert into `test_so_item` values (3, '00030', 'a0002', 2.00);
insert into `test_so_item` values (4, '00040', 'a0003', 5.00);


set foreign_key_checks = 1;

1.2代码

 @test
    public void test() {
        list<testsoitem> items = testsoitemservice.list();
        //1.当前全量数据
        log.info("1.当前全部数据:{}", items);
        ipage<testsoitem> page = new page<>();
        page.setcurrent(1);
        page.setsize(2);
        //2.分页查第一页
        ipage<testsoitem> items1 = testsoitemservice.page(page);
        log.info("2.第一页:{}", json.tojsonstring(items1));
        //3.删除
        testsoitemservice.removebyid(items1.getrecords().get(1).getid());
        log.info("3.已删除id:{}", items1.getrecords().get(1).getid());
        //4.add
        testsoitem addsoitem = new testsoitem();
        addsoitem.setlineno("00010");
        addsoitem.setsku("aa0793159");
        addsoitem.setqty(new bigdecimal(1));
        log.info("4:新增记录{}", json.tojsonstring(addsoitem));
        testsoitemservice.save(addsoitem);
        //5.分页查第2页
        page.setcurrent(2);
        ipage<testsoitem> items2 = testsoitemservice.page(page);
        log.info("5.第二页:{}", json.tojsonstring(items2));
    }

二、验证

1.验证前全部数据

<==    columns: id, line_no, sku, qty
<==        row: 1, 00020, a0001, 10.00
<==        row: 2, 00010, nt9531, 1.00
<==        row: 3, 00030, a0002, 2.00
<==        row: 4, 00040, a0003, 5.00
<==      total: 4

[testsoitem(lineno=00020, sku=a0001, qty=10.00), testsoitem(lineno=00010, sku=nt9531, qty=1.00), testsoitem(lineno=00030, sku=a0002, qty=2.00), testsoitem(lineno=00040, sku=a0003, qty=5.00)]

2.第一页数据

==>  preparing: select id,line_no,sku,qty from test_so_item limit ?,? 
==> parameters: 0(long), 2(long)
<==    columns: id, line_no, sku, qty
<==        row: 1, 00020, a0001, 10.00
<==        row: 2, 00010, nt9531, 1.00

{"current":1,"pages":2,"records":[{"id":1,"lineno":"00020","qty":10.00,"sku":"a0001"},{"id":2,"lineno":"00010","qty":1.00,"sku":"nt9531"}],"searchcount":true,"size":2,"total":4}

3.删除记录

==>  preparing: delete from test_so_item where id=? 
==> parameters: 2(long)
<==    updates: 1

4. 新增记录

==>  preparing: insert into test_so_item ( line_no, sku, qty ) values ( ?, ?, ? ) 
==> parameters: 00010(string), aa0793159(string), 1(bigdecimal)
<==    updates: 1

{"lineno":"00010","qty":1,"sku":"aa0793159"}

5.第二页数据

==>  preparing: select id,line_no,sku,qty from test_so_item limit ?,? 
==> parameters: 2(long), 2(long)
<==    columns: id, line_no, sku, qty
<==        row: 4, 00040, a0003, 5.00
<==        row: 5, 00010, aa0793159, 1.00

{"current":2,"pages":2,"records":[{"id":4,"lineno":"00040","qty":5.00,"sku":"a0003"},{"id":5,"lineno":"00010","qty":1.00,"sku":"aa0793159"}],"searchcount":true,"size":2,"total":4}

6. 验证后的数据

7. log

sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@2e6bac5a] was not registered for synchronization because synchronization is not active
<==    columns: id, line_no, sku, qty
<==        row: 1, 00020, a0001, 10.00
<==        row: 2, 00010, nt9531, 1.00
<==        row: 3, 00030, a0002, 2.00
<==        row: 4, 00040, a0003, 5.00
<==      total: 4
closing non transactional sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@232438a8]
jdbc connection [com.alibaba.druid.proxy.jdbc.connectionproxyimpl@7ed49ba] will not be managed by spring
2020-04-15 17:17:56.950 - info 1412 --- [           main] - [] c.z.p.s.impl.testsoitemserviceimpltest   : 1.当前全部数据:[testsoitem(lineno=00020, sku=a0001, qty=10.00), testsoitem(lineno=00010, sku=nt9531, qty=1.00), testsoitem(lineno=00030, sku=a0002, qty=2.00), testsoitem(lineno=00040, sku=a0003, qty=5.00)]


jdbc connection [com.alibaba.druid.proxy.jdbc.connectionproxyimpl@2907d3e8] will not be managed by spring
 jsqlparsercountoptimize sql=select  id,line_no,sku,qty  from test_so_item
<==    updates: 1
closing non transactional sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@2e6bac5a]
==>  preparing: select count(1) from test_so_item 
==> parameters: 
<==    columns: count(1)
<==        row: 4
==>  preparing: select id,line_no,sku,qty from test_so_item limit ?,? 
==> parameters: 0(long), 2(long)
<==    columns: id, line_no, sku, qty
<==        row: 1, 00020, a0001, 10.00
<==        row: 2, 00010, nt9531, 1.00
<==      total: 2
closing non transactional sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@70382eb1]
2020-04-15 17:18:24.496 - info 1412 --- [           main] - [] c.z.p.s.impl.testsoitemserviceimpltest   : 2.第一页:{"current":1,"pages":2,"records":[{"id":1,"lineno":"00020","qty":10.00,"sku":"a0001"},{"id":2,"lineno":"00010","qty":1.00,"sku":"nt9531"}],"searchcount":true,"size":2,"total":4}
creating a new sqlsession
sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@d9420bf] was not registered for synchronization because synchronization is not active
jdbc connection [com.alibaba.druid.proxy.jdbc.connectionproxyimpl@2907d3e8] will not be managed by spring
==>  preparing: delete from test_so_item where id=? 
==> parameters: 2(long)
<==    updates: 1
closing non transactional sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@d9420bf]
2020-04-15 17:18:24.597 - info 1412 --- [           main] - [] c.z.p.s.impl.testsoitemserviceimpltest   : 3.已删除id:2
2020-04-15 17:18:24.598 - info 1412 --- [           main] - [] c.z.p.s.impl.testsoitemserviceimpltest   : 4:新增记录{"lineno":"00010","qty":1,"sku":"aa0793159"}
creating a new sqlsession
sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@1145d71f] was not registered for synchronization because synchronization is not active
jdbc connection [com.alibaba.druid.proxy.jdbc.connectionproxyimpl@2907d3e8] will not be managed by spring
==>  preparing: insert into test_so_item ( line_no, sku, qty ) values ( ?, ?, ? ) 
==> parameters: 00010(string), aa0793159(string), 1(bigdecimal)
<==    updates: 1
closing non transactional sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@1145d71f]
creating a new sqlsession
sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@64aa7a33] was not registered for synchronization because synchronization is not active
jdbc connection [com.alibaba.druid.proxy.jdbc.connectionproxyimpl@2907d3e8] will not be managed by spring
 jsqlparsercountoptimize sql=select  id,line_no,sku,qty  from test_so_item
==>  preparing: select count(1) from test_so_item 
==> parameters: 
<==    columns: count(1)
<==        row: 4
==>  preparing: select id,line_no,sku,qty from test_so_item limit ?,? 
==> parameters: 2(long), 2(long)
<==    columns: id, line_no, sku, qty
<==        row: 4, 00040, a0003, 5.00
<==        row: 5, 00010, aa0793159, 1.00
<==      total: 2
closing non transactional sqlsession [org.apache.ibatis.session.defaults.defaultsqlsession@64aa7a33]
2020-04-15 17:18:24.721 - info 1412 --- [           main] - [] c.z.p.s.impl.testsoitemserviceimpltest   : 5.第二页:{"current":2,"pages":2,"records":[{"id":4,"lineno":"00040","qty":5.00,"sku":"a0003"},{"id":5,"lineno":"00010","qty":1.00,"sku":"aa0793159"}],"searchcount":true,"size":2,"total":4}
2020-04-15 17:18:24.735 - warn 1412 --- [      thread-31] - [] o.s.cloud.stream.binding.bindingservice  : trying to unbind 'sappurchaseorder-input', but no binding found.
2020-04-15 17:18:24.736 - info 1412 --- [      thread-31] - [] o.s.i.endpoint.eventdrivenconsumer       : removing {logging-channel-adapter:_org.springframework.integration.errorlogger} as a subscriber to the 'errorchannel' channel
2020-04-15 17:18:24.736 - info 1412 --- [      thread-31] - [] o.s.i.channel.publishsubscribechannel    : channel '{server.name}-1.errorchannel' has 0 subscriber(s).
2020-04-15 17:18:24.736 - info 1412 --- [      thread-31] - [] o.s.i.endpoint.eventdrivenconsumer       : stopped _org.springframework.integration.errorlogger
2020-04-15 17:18:24.767 - warn 1412 --- [      thread-32] - [] o.s.c.support.defaultlifecycleprocessor  : failed to stop bean 'inputbindinglifecycle'

三、结论

在使用limit分页查询时,做delete操作,会导致丢失数据。如案例中id=3 的记录,在第一、二页均没有查到。

四、建议

使用limit分页查询的问题：

1. 数据量比较大时,页数越大，查询性能越差。

   原因参考文章：

2. 查询时使用delete 进行物理删除时,会导致漏查询数据（同时更不建议使用物理删除,尽量使用逻辑删除）。