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id name datetime
1 a 2010-05-13 10:15:00
2 b 2010-05-14 09:10:00
3 d 2010-05-14 10:10:00

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update table_name set name='x' where datetime in (select max(datetime) as datetime from table_name)

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update table_name set name='x' where datetime in (select max(datetime) as datetime from table_name)

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update table_name a set name='x' where exists (
 select 1 from (
  select max(datetime) from table_name
 ) b where b.datetime=a.datetime
);

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update tble set name='x' where not exists (select 1 from tbl b where b.ttime<tble.ttime);

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update table_name set name='x' where datetime in (select max(datetime) as datetime from table_name)

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³öÏÖÕâÑùµÄ´íÎóŶ #1093 - You can't specify target table 'te_log' for update in from clause

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˼·£¬create table_name as select max(datetime) as datetime from table_name
È»ºóupdate table_name set name='x' where datetime in ÉÏÃæÄǸö±í;
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