Mysql senior operations in view of the index _ _ _ transaction accounts rights management

view

• View is a virtual table used to isolate the database
• Create a view
  • Creating a view is not allowed to have the same field name
  • create view view name as select statement;
• Modify View
  • alter view view name as select statement;
• Delete View
  • drop view view name
• A view is not easy to modify the query
• View of the role
  • Improved reusability, as a function
  • When the reconstruction of the database, does not affect the use of data
  • Improved security, allowing different users
  • Make the data more clearly

Affairs

• What is a transaction
  • It is a sequence of operations, these operations are either executed, or not executed, it is indivisible unit of work
• Four characteristics of the transaction (referred to as ACID)
  • Atomicity
  • consistency
    • Either all succeed or fail
  • Isolation
    • Before submitting a transaction, other things can not see, use a database row-level locking
  • Endurance

• Open transaction start transaction; or begin;


  start transaction;
  -- sql语句，必须所有的语句都执行完毕，不然就会回滚数据
  commit;

  • mysql client is enabled by default affairs, and is the default commit the transaction
  • Python is also enabled by default affairs, but requires manual submission
  • After the data is not submitted data rollback

index

• Index is a special file (the index table innodb data table is an integral part of the space), which contains pointers to all records of the reference data table
• A special data structure
• Direct reference database stored (pointer)
• Speed ​​up database query
• Open running time detection
  • set profiling=1;
• View time
  • show profiles;
• Creating an index
  • create index index name on table name (field name (length))
• Delete Index
  • drop index index name on table
• The establishment of too many index will affect the speed of updates and inserts

Account Management

• Need to use mysql database
• Check the user name account password
  • select host, user, authentication_string from user;
• Create an account and authorize
  • grant select on jing_dong.* to 'langwang'@'localhost' identified by '123456';