ndb_delete_all -c connection_string tbl_name -d db_name This deletes all rows from the table named tbl_name in the database named db_name. It is exactly equivalent to executing TRUNCATE db_name.tbl_name in MySQL. Options that can be used with ndb_delete_all are shown in the ...
UPDATE pay_stream a SET a.return_amount = 0 WHERE a.pay_id IN (SELECT b.pay_id FROM pay_main b WHERE b.user_name = '1388888888'); id select_type table partitions type possible_keys key key_len ref rows filtered Extra --- --- --- --- --- --- --- --- --- --- ---...
基本DELETE:DELETE FROM table_name WHERE condition; 删除所有行:DELETE FROM table_name; 或TRUNCATE TABLE table_name;(后者更快,但会重置自增ID) 应用场景: 删除过期的数据。 删除不再需要的记录。 清理数据库以释放空间。 遇到的问题及解决方法: 误删数据:在执行 DELETE 语句之前,务必确保已经做好了数据备份...
A column value can't be deleted. It can be dropped. Or it can be set to null if it's defined in create table code as nullable, or it can be set to 0 if it's numeric or '' if it's a string. So in your case ... update xf_user set sonnb_xengallery_video_count=0; ....
DELETE FROM Newcate; Explanation: The purpose of this SQL code is to delete all rows from the Newcate table. DELETE FROM Newcate: This line specifies the target table from which all rows will be deleted, which is Newcate. Example: MySQL DELETE with ORDER BY for limited number of rows ...
If you delete the row containing the maximum value for anAUTO_INCREMENTcolumn, the value is not reused for aMyISAMorInnoDBtable. If you delete all rows in the table withDELETE FROMtbl_name(without aWHEREclause) inautocommitmode, the sequence starts over for all storage engines exceptInnoDBand...
DELETEFROMemployees; All rows in theemployeestable deleted. MySQLDELETEandLIMITclause# If you want to limit the number of rows to be deleted, you use theLIMITclause as follows: 1 2 DELETEFROMtable LIMITrow_count; Note that the order of rows in a table is unspecified, therefore, when you ...
1 row in set, 1 warning (0.00 sec) 1. 2. 3. 4. 5. 6. 7. 自动提交关闭: mysql> set autocommit=0; Query OK, 0 rows affected (0.00 sec) mysql> select @@autocommit; +---+ | @@autocommit | +---+ | 0 | +---+ 1 row in set ...
EXPLAIN SELECT * FROM yp_user IGNORE INDEX(idx_gender) where gender=1 ; 在我看来,虽然有MySQL Hints这种好用的工具,但我建议还是不要再生产环境使用,因为当数据量增长时,你压根儿都不知道这种索引的方式是否还适应于当前的环境,还是得配合DBA从索引的结构上去优化。
partitionedtabletwitha partition named p0, executing the statementDELETEFROMt PARTITION (p0) has the same effectonthetableasexecutingALTERTABLEtTRUNCATEPARTITION (p0);inboth cases,allrowsinpartition p0 are dropped. PARTITION can be used alongwithaWHEREcondition,inwhichcasethe ...