create database test
go
use test
go
create table test123
(
id int,
word varchar(50),
)
go
insert into test123 (id,word)values(1,'1')
insert into test123 (id,word)values(2,'2')
insert into test123 (id,word)values(3,'3')
insert into test123 (id,word)values(4,'4')
insert into test123 (id)values(6)
insert into test123 (id)values(7)
insert into test123 (id)values(8)
insert into test123 (id)values(9)
insert into test123 (word)values('10')
select * from test123
select * from test123 where id is null
select * from test123 where id is not null
select * from test123 where word is null
select * from test123 where word is not null
本文提供了一个SQL操作的具体示例,包括创建数据库、表,插入数据,以及如何使用NULL和NOT NULL进行查询。通过这些示例,读者可以了解基本的SQL语法和如何处理NULL值。
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