tinyint  
 has not paid attention to the bit type. After consulting the data, we know that bit is stored in binary format:  bounded 0"  or  bounded 1" 
 its storage unit is directly  bit , while the smallest unit of  tinyint  is 1 byte. 
 however, some people say that  bit  does not support indexing. Source:  [MySQL] stories triggered by bit types  
 personally, I think: because  php  is weakly typed,  bit  type query is not as convenient as  tinyint , 
 is said to be more suitable for  java . If you have any trouble, explain why? And their differences and usage scenarios? 
