数据库表的操作方式分为

\u6570\u636e\u5e93 \u8868\u7684\u64cd\u4f5c

\u95f2\u6765\u65e0\u4e8b\uff0c\u53ea\u505a\u540e\u4e00\u9898\u5427\uff01

(1)ALTER TABLE xs ALTER COLUMN \u4e13\u4e1a\u540d char(30) // char\u662f\u5b57\u6bb5\u7c7b\u578b(30)\u662f\u957f\u5ea6
(2)ALTER TABLE xs ADD \u903e\u671f\u672a\u8fd8\u6570 int

(3)ALTER TABLE xs DROP COLUMN \u6027\u522b
ALTER TABLE xs DROP COLUMN \u51fa\u751f\u65f6\u95f4

(4)sp_rename xs book

(5) Insert into book (\u501f\u4e66\u8bc1\u53f7,\u59d3\u540d,\u4e13\u4e1a\u540d,\u501f\u4e66\u6570,\u7167\u7247) values('01050022' ,'\u738b\u5927\u4e00','\u8ba1\u7b97\u673a',10,null)
(6) Delete From book
(7)drop table book

INSERT INTO New_MyData(NameID,Allc1,Allc2,Allc3,Allc4,All)
SELECT NameID,
SUM(CASE Allc WHEN '\u6ee1\u610f' THEN 1 ELSE 0 END),
SUM(CASE Allc WHEN '\u4e00\u822c' THEN 1 ELSE 0 END),
SUM(CASE Allc WHEN '\u4e0d\u6ee1\u610f' THEN 1 ELSE 0 END),
SUM(CASE Allc WHEN '\u672a\u5e73' THEN 1 ELSE 0 END),
SUM(1)
FROM myDat GROUP BY NameID

增删改查

查主要为select 语句 select sysdate from dual;

删主要为删除数据库数据 delete from t_user 删除t_user表所有数据，或者使用truncate t_user;

改就是修改数据表内的某条记录。 update t_user t set t.user_name='john';

增就是往数据表内添加记录，主要是insert语句,语法：insert.. into....或select ..... into...

student(sno,sname,ssex,sage,sdpt)course(cno,cname,cpno,ccrdit)sc(sno,cno,grade)
查询某列 select sno，sname from student
删除表 drop table student restrict/cascade
改列的限制条件 alter student alter column sage int
加一列 alter table student add s_entrance date
插入一行 insert into student (sno,sname) values ('29900','王洁')
修改一列 update student set sage=22/sage+1 where sno='43434'
删除某个一行 delete from student where sno='4324536'

扩展阅读：一键生成数据分析图 ... 数据输入的三种方式 ... 数据库分为哪两类 ... 数据库表分为哪三种 ... 数据分析的四个步骤 ... 连接数据库的四种方式 ... 数据库模板图 ... 数据集分为哪三类 ... 数据传输方式可分为哪三种 ...