mysql日常处理

http://blog.csdn.net/zengxuewen2045/article/details/52349731

https://github.com/enmotplinux/On-Site-Inspection/tree/master/lib

http://www.jianshu.com/p/5dd73a35d70f

http://makaidong.com/baidu_37107022/1/5211_9346170.html

https://i.cnblogs.com/EditPosts.aspx?postid=7726305

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# mysql sys db user
select * from host_summary G

select * from user_summary G

select host,current_connections,statements from host_summary G
#show full processlist;
select conn_id,current_statement,last_statement from session G

select * from io_global_by_file_by_bytes order by total desc limit 3 G

select * from memory_global_total G;

select * from innodb_buffer_stats_by_schema order by allocated desc limit 2;

select * from innodb_buffer_stats_by_table limit 2;

#每个连接使用多少内存
select b.user,current_count_used,current_allocated,current_avg_alloc,current_max_alloc,total_allocated,current_statement
from memory_by_thread_by_current_bytes a,session b where a.thread_id = b.thd_id G

#查看表自增字段最大值和当前
select * from schema_auto_increment_columns G
#索引使用情况
select * from schema_index_statistics limit 10;
#冗余索引
select * from schema_redundant_indexes limit 3 G
select * from schema_unused_indexes limit 3 G

#MYSQL 内部多少线程在运行
select user,count(*) from processlist group by user;

==================

mysql 查看所有没有主键的表
SELECT
#CONCAT("truncate table ",table_name,";")
table_name
FROM
information_schema. TABLES
WHERE
table_schema = 'scdm'
AND TABLE_NAME NOT IN (
SELECT
table_name
FROM
information_schema.table_constraints t
JOIN information_schema.key_column_usage k USING (
constraint_name,
table_schema,
table_name
)
WHERE
t.constraint_type = 'PRIMARY KEY'
AND t.table_schema = 'scdm'
)

获取缺失主键表信息的MYSQL语句
SELECT a.`TABLE_SCHEMA` AS DB_NAME , a.`TABLE_NAME` , a.`TABLE_ROWS` ,a.`ENGINE` -- , a.*
FROM
information_schema.`TABLES` a
LEFT JOIN information_schema.`TABLE_CONSTRAINTS` b
ON a.`TABLE_NAME` = b.`TABLE_NAME` AND a.`TABLE_SCHEMA` = b.`TABLE_SCHEMA`
WHERE b.`TABLE_SCHEMA` IS NULL
AND a.`TABLE_TYPE` = 'BASE TABLE'
AND a.`TABLE_SCHEMA` NOT IN ('information_schema','test','mysql','performance_schema')
ORDER BY DB_NAME ,a.`TABLE_ROWS` DESC ;

mysql如何获取主键的字段名
SELECT k.column_name
FROM information_schema.table_constraints t
JOIN information_schema.key_column_usage k
USING (constraint_name,table_schema,table_name)
WHERE t.constraint_type='PRIMARY KEY'
AND t.table_schema='db'
AND t.table_name=tbl'

两种获取MySql数据库中所有表的主键和外键约束信息的Sql语句

第一种方法：是网上的方法，可以直接使用，【MySQL 查看数据库中有主外键关系的表信息】

SELECT C.TABLE_SCHEMA            拥有者,
           C.REFERENCED_TABLE_NAME 父表名称 ,
           C.REFERENCED_COLUMN_NAME 父表字段 ,
           C.TABLE_NAME             子表名称,
           C.COLUMN_NAME            子表字段,
           C.CONSTRAINT_NAME        约束名,
           T.TABLE_COMMENT          表注释,
           R.UPDATE_RULE            约束更新规则,
           R.DELETE_RULE            约束删除规则
      FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE C
      JOIN INFORMATION_SCHEMA. TABLES T
        ON T.TABLE_NAME = C.TABLE_NAME
      JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS R
        ON R.TABLE_NAME = C.TABLE_NAME
       AND R.CONSTRAINT_NAME = C.CONSTRAINT_NAME
       AND R.REFERENCED_TABLE_NAME = C.REFERENCED_TABLE_NAME
      WHERE C.REFERENCED_TABLE_NAME IS NOT NULL ;

UPDATE/DELETE_RULE 类型：
1. CASCADE: 从父表中删除或更新对应的行，同时自动的删除或更新自表中匹配的行。ON DELETE CANSCADE和ON UPDATE CANSCADE都被InnoDB所支持。
2. SET NULL: 从父表中删除或更新对应的行，同时将子表中的外键列设为空。注意，这些在外键列没有被设为NOT NULL时才有效。 ON DELETE SET NULL和ON UPDATE SET SET NULL都被InnoDB所支持。
3. NO ACTION: InnoDB拒绝删除或者更新父表。
4. RESTRICT: 拒绝删除或者更新父表。指定RESTRICT（或者NO ACTION ）和忽略ON DELETE或者ON UPDATE选项的效果是一样的。
5. SET DEFAULT: InnoDB目前不支持。

第二种方法：

select O.CONSTRAINT_SCHEMA,O.CONSTRAINT_NAME,O.TABLE_SCHEMA,O.TABLE_NAME,O.COLUMN_NAME,O.REFERENCED_TABLE_SCHEMA,O.REFERENCED_TABLE_NAME,O.REFERENCED_COLUMN_NAME,O.UPDATE_RULE,O.DELETE_RULE,O.UNIQUE_CONSTRAINT_NAME,T.CONSTRAINT_TYPE from (
select K.CONSTRAINT_SCHEMA,K.CONSTRAINT_NAME,K.TABLE_SCHEMA,K.TABLE_NAME,K.COLUMN_NAME,K.REFERENCED_TABLE_SCHEMA,K.REFERENCED_TABLE_NAME,K.REFERENCED_COLUMN_NAME,R.UPDATE_RULE,R.DELETE_RULE,R.UNIQUE_CONSTRAINT_NAME from information_schema.KEY_COLUMN_USAGE K LEFT join information_schema.REFERENTIAL_CONSTRAINTS R on K.CONSTRAINT_NAME=R.CONSTRAINT_NAME)
as O inner join Information_schema.TABLE_CONSTRAINTS T on O.Table_Name=T.TABLE_NAME and T.CONSTRAINT_NAME=O.CONSTRAINT_NAME where O.CONSTRAINT_SCHEMA!='mysql' and O.CONSTRAINT_SCHEMA!='sys';

第二种方法会列出所有的非系统数据所有表的主键信息和外键信息，第一种方法只会列出外键约束信息。

-----------

use information_schema;
show tables;
select * from KEY_COLUMN_USAGE
where
COLUMN_NAME='xx_id';

---------------

#2)

mysqladmin -uroot -p123456 -h192.168.1.139 -P3306 -r -i 5 ext |
awk -F"|" '{
if($2 ~ /Variable_name/){
print " <------------- " strftime("%H:%M:%S") " ------------->";
}
if($2 ~ /Questions|Queries|Innodb_rows|Com_select |Com_insert |Com_update |Com_delete |Innodb_buffer_pool_read_requests/)
print $2 $3;
}'

#3）
mysqladmin -P3306 -uroot -p123456 -h192.168.1.139 -r -i 5 ext |
awk -F"|"
"BEGIN{ count=0; }"
'{ if($2 ~ /Variable_name/ && ++count == 1){
print "----------|---------|--- MySQL Command Status --|----- Innodb row operation ----|-- Buffer Pool Read --";
print "---Time---|---QPS---|select insert update delete| read inserted updated deleted| logical physical";
}
else if ($2 ~ /Queries/){queries=$3;}
else if ($2 ~ /Com_select /){com_select=$3;}
else if ($2 ~ /Com_insert /){com_insert=$3;}
else if ($2 ~ /Com_update /){com_update=$3;}
else if ($2 ~ /Com_delete /){com_delete=$3;}
else if ($2 ~ /Innodb_rows_read/){innodb_rows_read=$3;}
else if ($2 ~ /Innodb_rows_deleted/){innodb_rows_deleted=$3;}
else if ($2 ~ /Innodb_rows_inserted/){innodb_rows_inserted=$3;}
else if ($2 ~ /Innodb_rows_updated/){innodb_rows_updated=$3;}
else if ($2 ~ /Innodb_buffer_pool_read_requests/){innodb_lor=$3;}
else if ($2 ~ /Innodb_buffer_pool_reads/){innodb_phr=$3;}
else if ($2 ~ /Uptime / && count >= 2){
printf(" %s |%9d",strftime("%H:%M:%S"),queries);
printf("|%6d %6d %6d %6d",com_select,com_insert,com_update,com_delete);
printf("|%6d %8d %7d %7d",innodb_rows_read,innodb_rows_inserted,innodb_rows_updated,innodb_rows_deleted);
printf("|%10d %11d ",innodb_lor,innodb_phr);
}}'