Let’s check which rows got deleted. select * from customers2 go Scenario 2.b: Delete all duplicate records but keep the first original one Let’s first truncate the customers2 table and add the same rows again. Truncate Table customers2 go Insert into customers2 Values(1, 'John', 'Pari...
处理重复行 当SQL 对 SELECT 语句进行求值时,根据满足 SELECT 语句的搜索条件的行数,可能有几行符合结果表中的条件。 结果表中的某些行可能重复。 您可以使用 DISTINCT 关键字指定不需要任何重复项,后跟表达式列表: SELECT DISTINCTJOB, SEX ... DISTINCT 表示您只想选择唯一行。 如果所选行与结果表中的另一行重...
write_rows :Duplicate entry(1062错误)主键冲突,主要表现为重复插入已经存在的记录; update_rows :Can't find record(1032错误),无法发现需要更新的行记录。 sql_slave_skip_counter 参数说明: 从官方解释知道,sql_slave_skip_counter以event 为单位 skip ,直到 skip 完第N个 event 所在的 event group 才停止。
obclient> USE db1; Database changed obclient> CREATE TABLE test (c1 INT PRIMARY KEY, c2 VARCHAR(3)); Query OK, 0 rows affected 更多CREATE TABLE 语句相关的语法说明,请参见 CREATE TABLE 章节。 2.2 查看表 使用SHOW CREATE TABLE 语句查看建表语句。 示例: 查看表 test 的建表语句。 代码语言:...
How to Delete the Duplicate Rows Delete key1by Büşra ÖZCOŞKUNCC BY-SA 4.0 Now you've identified the copies, you often want to delete the extra rows. For simplicity, I'm going to assume that either the rows are exact copies or you don't care which you remove. ...
SELECTDISTINCT*INTOduplicate_tableFROMoriginal_tableGROUPBYkey_valueHAVINGCOUNT(key_value) >1DELETEoriginal_tableWHEREkey_valueIN(SELECTkey_valueFROMduplicate_table)INSERToriginal_tableSELECT*FROMduplicate_tableDROPTABLEduplicate_table 本指令碼依照指定順序執行下列動作: ...
dept_id, count(*) from employees group by dept_id having count(*)<10; +---+---+ | dept_id | count(*) | +---+---+ | 1 | 8 | | 2 | 5 | | 3 | 6 | | 6 | 9 | | 8 | 3 | +---+---+ 5 rows in set (0.00 sec) 查询结果中如果有where,group by(包含having...
When you use the UNION operator, you can also specify whether the query results should include duplicate rows, if any exist, by using the ALL key word. The basic SQL syntax for a union query that combines two SELECT statements is as follows: ...
ERROR 1062 (23000): Duplicate entry '1000000001' for key 'test1.uq_card_no' mysql> update ignore test1 set card_no=card_no +1; Query OK, 2 rows affected, 1 warning (0.02 sec) Rows matched: 3 Changed: 2 Warnings: 1 mysql> show warnings; ...
DUPLICATE KEY:key列相同的记录,同时存在于PALO中,适合存储明细数据或者数据无聚合特性的业务场景。 partition_desc 语法: PARTITION BY RANGE (k1) ( PARTITION partition_name VALUES LESS THAN MAXVALUE|("value1") [("key"="value")], PARTITION partition_name VALUES LESS THAN MAXVALUE|("value2") [(...