Question

SQL高级查询所有语法，比如模糊查询和嵌套查询

Answer 1

模糊查询 :select * from student where name like '%'+'hello'+'%'
嵌套查询 : select * from student where id = (select id from student where name = '张三' )
.....
具体的可以参照sql的帮助文档

Answer 2

SELECT * FROM 表

Answer 3

1.表的别名：
SELECT {table_alias.column}[,...n]
FROM table_name [AS] table_alias [,...n]

2.内连接
SELECT select_list FROM table1,table2 WHERE table1.column1=table.column2
或
SELECT select_list FROM table1 [INNER] JOIN table2 ON table1.column1=table2.column2

3.外连接
(1)左连接，用“*=”或“LEFT JOIN”，返回左边的表的全部数据
(2)右连接，用“=*”或“RIGHT JOIN”，返回右边的表的全部数据
(3)完全连接，用“FULL OUTER JOIN”

4.联合查询，用于合并所有查询结果集中的全部行数据，命令格式如下：
select_statement
UNION [ALL] select_statement
[UNION [ALL] select_statement][...n]

5.统计函数有：SUM(), AVG(), COUNT(), MAX(), MIN()，命令格式如下：
function_name([ALL|DISTINCT] expression)

6.嵌套
(1)使用比较运算符的子查询，如：
SELECT * FROM Score WHERE score>(SELECT AVG(score) FROM Score)
(2)使用IN的子查询，如：
SELECT * FROM Score WHERE [student id] IN (SELECT [student id] FROM Student WHERE sex=1)
(3)使用EXISTS的子查询，如：
SELECT * FROM Student WHERE EXISTS (SELECT * FROM Score WHERE score<70)
(4)用于替代表达式的子查询，如：
SELECT s.[student id],[name],'student score'=(SELECT SUM(score) FROM Score WHERE s.[student id]=score.[student id]) FROM Student AS s

Answer 4

你可以去找本数据库想关的书看看
SQL比较容易学
一般用到的SQL都是比较简单的