So the query will be as follows. With Duplicates as (select distinct a.custid as Customer_ID from customers2 a join customers2 b on a.custid <> b.custid and a.CustName = b.CustName and a.CustCity = b.CustCity and a.Passport_Number = b.Passport_Number ) Delete from Customers2 whe...
After a while you'll likely become bored of this. So you create a job to remove the duplicates. But this doesn't solve the problem. There will still be times between job runs where the table could have duplicates. A better solution is to stop people entering new copies. You could do ...
"steps": [ { "expanded_query": "/* select#2 */ select `t_table_2`.`id` from `t_table_2` where (`t_table_2`.`uid` = 1)" }, { "transformation": { "select#": 2, "from": "IN (SELECT)", "to": "semijoin", "chosen": false } }, { "transformation": { "select#":...
"expanded_query":"/* select#1 */ select `t_table_1`.`id` AS `id`,`t_table_1`.`task_id` AS `task_id` from `t_table_1` where <in_optimizer>(`t_table_1`.`task_id`,<exists>(/* select#2 */ select `t_table_2`.`id` from `t_table_2` where ((`t_table_2`.`uid` ...
) AS duplicates WHERE row_num > 1; 在这个例子中,使用`ROW_NUMBER()`函数为重复的记录分配行号,然后删除行号大于1的记录。 综上所述,DELETE语句是SQL中常用的命令之一,用于删除数据库中的记录。本文介绍了DELETE语句的基本语法和一些实例代码,希望能对读者理解和使用DELETE语句提供帮助。
/home/Code/GitHub/stonedb/sql/handler.cc:8230#2 0x000000000247ed8c in mysql_update(thd=0x7fdcec000bc0, fields=..., values=..., limit=18446744073709551615, handle_duplicates=DUP_ERROR, found_return=0x7fe0c81c9c58, updated_return=0x7fe0c81c9c50) at /home/Code/GitHub/stonedb/...
name(name),addindexidx_phone(phone);QueryOK,0rowsaffected(6.00sec)Records:0Duplicates:0Warnings:...
Write a SQL query to delete all duplicate email entries in a table namedPerson, keeping only unique emails based on itssmallestId. +---+---+ | Id | Email | +---+---+ | 1 | john@example.com | | 2 | bob@example.com | | 3 | john@example...
obclient> CREATE TABLE tbl1(col1 INT PRIMARY KEY, col2 INT); Query OK, 0 rows affected obclient> INSERT INTO tbl1 VALUES(1,1),(2,2),(3,3),(4,4); Query OK, 4 rows affected Records: 4 Duplicates: 0 Warnings: 0 obclient> SELECT * FROM tbl1; +---+---+ | COL1 | COL...
将duplicate_table 的去重数据插入到 no_duplicate_table; 代码语言:javascript 代码运行次数:0 运行 AI代码解释 mysql> insert no_duplicate_table select distinct * from duplicate_table; Query OK, 3 rows affected (0.03 sec) Records: 3 Duplicates: 0 Warnings: 0 通过重命名表,实现原子的去重操作; ...