mysql联合索引最左匹配原则的底层实现原理解读

select * from table_name where a = '1' and b = '2' and c = '3' 
select * from table_name where b = '2' and a = '1' and c = '3' 
select * from table_name where c = '3' and b = '2' and a = '1' 

select * from table_name where a = '1' 
select * from table_name where a = '1' and b = '2'  
select * from table_name where a = '1' and b = '2' and c = '3'

select * from table_name where  b = '2' 
select * from table_name where  c = '3'
select * from table_name where  b = '1' and c = '3' 

select * from table_name where a = '1' and c = '3' 

select * from table_name where a like 'As%'; //前缀都是排好序的，走索引查询
select * from table_name where  a like '%As'//全表查询
select * from table_name where  a like '%As%'//全表查询

select * from table_name where  a > 1 and a < 3

select * from table_name where  a > 1 and a < 3 and b > 1;

select * from table_name where  a = 1 and b > 3;

select * from table_name order by a,b,c limit 10;

select * from table_name order by b,c,a limit 10;

select * from table_name order by a limit 10;
select * from table_name order by a,b limit 10;

select * from table_name where a =1 order by b,c limit 10;