MySQL - related operations Index

- Index to view a table 
Show index  from  [ table name ] ; 

- create a regular index 
    
    - created directly (here refers to the length of the field into the first few index, the index has become short, if you do not specify a length, the all data stored in the field index) 
    Create  index  [ index name ]  ON  [ table name ] ( [ field name ] ( [ length ] )); 
    
    - modify the table structure added 
    ALTER  table  [ table ]  the Add  index  [ index name ] ( [ field name ] ( [ length ])); 

- Delete Index 

    - delete 
    drop  index  [ index name ]  ON  [ Table Name ] ; 
    
    - modify delete table structure 
    ALTER  Table  [ table name ]  drop  index  [ index name ] ;