SQL语法

• 在表中选择列
  select 列名 from 表名
• 选择所有列
  select * from 表名
• 返回唯一值
  select distinct 列名 from 表名
• where
  select * from 表名 where city = 'beijng'
  select * from 表名 where year = 1993
• OR AND
  select * from 表名 where city = 'beijing' and year=1993
• ORDER BY
  select * from tablename ORDER BY col1 DESC, col2 ASC
• 插入新的行
  insert into tablename (col1, col2) values ('q', 'w'）
• 更新数据
  update tablename set col1 = 'newdata', col2 = 'newdata' where col='zhi'
• 删除行
  delete from tablename where col = 'data'
  delete * from tablename