when I try to insert a row in mysql table I've got this error: SQLException: You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use n
报错信息:Mysql You can change this value on the server by setting the max_allowed_packet' variable. Packet for query is too large (6832997 > 1048576). You can change this value on the server by setting the max_allowed_packet' variable. 解释: 用于查询的数据包太大(6832997> 1048576)。 您...
其中对 insert 的加锁过程是这样说的(这应该是网络上介绍 MySQL 加锁机制被引用最多的文档,估计也是被误解最多的文档):INSERT sets an exclusive lock on the inserted row. This lock is an index-record lock, not a
1 row affected (0.00 sec) mysql> select * from dept_bak; +---+---+---+ | DEPTNO | DNAME | LOC | +---+---+---+ | 10 | abc | tj | | 10 | abc | tj | +---+---+---+ 2 rows in set (0.00 sec) mysql> rollback; Query OK, 0 rows affected (0.00 sec) mysql...
如果事务T对数据A加上共享锁后,则其他事务只能对A再加共享锁,不能加排他锁。获准共享锁的事务只能读数据,不能修改数据。 用法 SELECT ... LOCK IN SHARE MODE; 在查询语句后面增加LOCK IN SHARE MODE,Mysql会对查询结果中的每行都加共享锁,当没有其他线程对查询结果集中的任何一行使用排他锁时,可以成功申请...
第一次看 MySQL 源码可能会有些不知所措,调着调着就会迷失在深深的调用层级中,我们看insert语句的调用堆栈,一开始时还比较容易理解,从mysql_parse->mysql_execute_command->mysql_insert->write_record->handler::ha_write_row->innobase::write_row->row_insert_for_mysql,这里就进入 InnoDb 引擎了。
提到MySQL的Insert语句,你肯定不陌生,或许已经张口就来:不就是insert into table values(xxx,xxx,xxx)嘛!没错,但在实战中,根据不同的需求场景,插入操作在语法、执行方式上的用法多种多样。今天,我来给小伙伴们从这两方面分享一下搬砖心得,如果你有疑问或好的想法,记得在评论区给我留言,我会在搬砖之余和大家一...
ha_innobase::write_row->row_insert_for_mysql->row_insert_for_mysql_using_ins_graph->row_mysql_convert_row_to_innobase->fts_create_doc_id->fts_get_next_doc_id->fts_trx_add_op->fts_trx_table_add_op fts_get_next_doc_id与fts_trx_table_add_op是比较重要的两个函数,fts_get_next_doc...
1 row in set (0.04 sec) //关闭半同步strace日志 mysql> set global rpl_semi_sync_slave_trace_level = 32; Query OK, 0 rows affected (0.00 sec) mysql> show variables like 'rpl_semi_sync_slave_trace_level'; +---+---+ | Variable_name | ...
Named references to the old and new row are already possible in these statements. New syntax INSERT ... VALUES A new optional AS clause is allowed after the VALUES clause: INSERT ... VALUES(...) opt_alias ON DUPLICATE KEY UPDATE ... <opt_alias> ::= /* empty */ | AS <new row ...