Now we have realized that custid 1, 4 & 5 are duplicate. The self-join statement accompanied by delete statement will give us the desired output of keeping the last duplicate record by eliminating all the previous duplicate records. We will use theCommon Table Expression (CTE)and put the Sel...
WITHDuplicateRecordsAS(SELECT*,ROW_NUMBER()OVER(PARTITIONBYOrderID,ProductNameORDERBYOrderDate)ASRowNumFROMSalesRecords)DELETEFROMDuplicateRecordsWHERERowNum>1; 1. 2. 3. 4. 5. 6. 7. 在这里,我们采用了“折叠块”形式来隐藏更复杂的命令,便于使用者来快速定位核心内容。 /* 高级命令:可用于更复杂的数...
How to Delete Duplicate Records in SQL Server Usually on daily basis we usually need to perform removing duplicate records from a table. This post can help you to understand “How to Delete Duplicate Records in SQL Server”. Here consider an example for removing duplicate records. IF EXISTS(SE...
使用子查询和诸如 MIN 这样的聚合函数,任意选择并保留一个 ID(本例中 NAME 相同的情况下只有最小的 ID 会被保留)。1 delete from dupes 2 where id not in ( select min(id) 3 from dupes 4 group by name ) SQL CopySQL 删除重复记录 扩展知识如果要删除重复记录,首先要明确两行数据在什么条件下才会...
Duplicate Weedout: Run the semijoinasifit was ajoinandremove duplicate recordsusinga temporary table. FirstMatch:Whenscanning the inner tablesforrow combinationsandthere are multiple instancesofa given valuegroup, choose one rather than returning them all. This"shortcuts"scanningandeliminates productionof...
\text{Unique Records} = \text{Total Records} - \text{Duplicate Records} ] 调试步骤 接下来,我们需要通过 SQL 语句来识别和删除重复的记录。调试过程中,我们要仔细分析日志,以确定哪条记录应被保留。 下面是一个调试命令,用于选择重复记录并检查相关日志: ...
-- Incorrect - this will remove all sets of duplicate records. DELETE invoices FROM invoices i INNER JOIN (SELECT invoice_number FROM invoices GROUP BY invoice_number HAVING COUNT(*) > 1) x WHERE i.invoice_number = x.invoice_number; ...
#Delete duplicate records primary key conflict #Write by xuanzhi2015-01-12mysql=/usr/local/mysql-5.1.66-3310/bin/mysql sock=/data/mysql-slave-3310/mysql.sockpasswd=123456whiletruedoSQL_THREAD=`$mysql -uroot -p$passwd-S $sock -e'show slave status\G'|egrep'Slave_SQL_Running'|awk'{print...
4.16. Deleting Duplicate Records Problem You want to delete duplicate records from a table. Consider the following table: create table dupes (id integer, name varchar(10))insert into dupes values (1, 'NAPOLEON') insert into dupes values (2, 'DYNAMITE') ...
1、查找表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断 select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1) 2、删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录 delete from people wher...