Question

总结

查询的完整格式 ^_^ 不要被吓到 其实很简单 ! _ !

SELECT select_expr [,select_expr,...] [      
      FROM tb_name
      [WHERE 条件判断]
      [GROUP BY {col_name | postion} [ASC | DESC], ...] 
      [HAVING WHERE 条件判断]
      [ORDER BY {col_name|expr|postion} [ASC | DESC], ...]
      [ LIMIT {[offset,]rowcount | row_count OFFSET offset}]
]

• 完整的select语句

select distinct *
from 表名
where ....
group by ... having ...
order by ...
limit start,count

• 执行顺序为：
  • from 表名
  • where ....
  • group by ...
  • select distinct *
  • having ...
  • order by ...
  • limit start,count
• 实际使用中，只是语句中某些部分的组合，而不是全部