# 总查询
sql
EXPLAIN SELECT * FROM `city`;
# 范围查询
sql
EXPLAIN SELECT * from `city` where ID>5 and ID<20;

#主键查询
sql
EXPLAIN SELECT * from `city` where ID=5;

# 索引查询
sql
EXPLAIN SELECT * from `city` where CountryCode='NLD';
# 普通索引
sql
EXPLAIn SELECT * from `city` where Name='haag';

sql
EXPLAIN SELECT * from `city` where CountryCode in ('NLD','DZA');
