Tag Archives: Mysql

DELETE p from a p inner JOIN b i on p.id=i.pic_id  where ……;

where条件之后随便写

1、使用not in，容易理解，效率低

select distinct A.ID from A where A.ID not in (select ID from B)

2、使用left join…on… ，B.ID isnull表示左连接之后在B.ID字段为null的记录

select A.ID from A left join B on A.ID=B.ID where B.ID is null

[client]
port = 3306
socket = “D:/mysql/mysql.sock”

[mysqld]
port= 3306
socket = “D:/mysql/mysql.sock”
basedir = “D:/mysql”
tmpdir = “D:/tmp”
datadir = “D:/mysql/data”
pid_file = “mysql.pid”
key_buffer = 64M
max_allowed_packet = 512M
sort_buffer_size = 5120K
net_buffer_length = 256K
read_buffer_size = 1024K
read_rnd_buffer_size = 5120K
myisam_sort_buffer_size = 256M
log_error = “mysql_error.log”
lower_case_table_names=1

plugin_dir = “D:/mysql/lib/plugin/”

server-id = 1

innodb_data_home_dir = “D:/mysql/data”
innodb_data_file_path = ibdata1:10M:autoextend
innodb_log_group_home_dir = “D:/mysql/data”
innodb_buffer_pool_size = 256M
innodb_additional_mem_pool_size = 32M

innodb_log_file_size = 640M
innodb_log_buffer_size = 64M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 50
wait_timeout = 2880000
interactive_timeout = 2880000

[mysqldump]
quick
max_allowed_packet = 512M

[mysql]
no-auto-rehash

[isamchk]
key_buffer = 200M
sort_buffer_size = 200M
read_buffer = 32M
write_buffer = 32M

[myisamchk]
key_buffer = 200M
sort_buffer_size = 200M
read_buffer = 32M
write_buffer = 32M

[mysqlhotcopy]
interactive-timeout