python 簡單的數據庫 sqlite

'''
練習：
1,建立一個學生成績表 Grades，學號  姓名  成績  名次
CREATE TABLE Grades (num INTEGER PRIMARY KEY,name TEXT,grade INTEGER,rank INTEGER)
2，往表中插入10數據
INSERT IN TO Grades (num,name,grade,rank) VALUES (1,’zhangsan’,398,20)
3，查詢成績大於60分的人的名字
SELECT name,grade FROM grades WHERE grade > 60
4，查詢成績小於60分的人的個數
SELECT COUNT(*) FROM grades WHERE grade < 60
5，把成績小於60分的人的成績修改成60分
UPDATE grades SET grade = 60 WHERE grade < 60
6，刪除全部學號小於100的人的信息
DELETE FROM grades WHERE num < 100
6，查詢姓「張」的人的全部信息
SELECT * FROM grades WHERE name LIKE '張%'
7，查詢全部人的成績，按照成績從高到低排列
SELECT grade FROM grades ORDER BY grade DESC
8，查詢全部人的成績，按照名次從小到大排列
SELECT grade FROM grades ORDER BY rank ASC
'''
import sqlite3
connect = sqlite3.connect('database01.db')
cursor = connect.cursor()
# 插入一張表，學生成績表Grades: num, name;grade;rank
sql = "CREATE TABLE Grades(num INTEGER PRIMARY KEY,name TEXT,grade INTEGER,rank INTEGER)"
#cursor.execute(sql)
# 2 添加數據
sql = "INSERT INTO Grades(num,name,grade,rank) VALUES (10,'王昭君',600,10)"
#cursor.execute(sql)
connect.commit()

# 3 查詢成績大於60 分的人的名字
sql = 'SELECT name,grade FROM Grades WHERE grade> 60'
rs = cursor.execute(sql)
rs = list(rs)
print(rs)
connect.commit()
# 查詢成績小於400 分的人的名字
sql = 'SELECT COUNT(*) FROM Grades WHERE grade<400'
rs = cursor.execute(sql)
rs = list(rs)
print(rs)
connect.commit()
# 5 把成績小於400的成績改成 400
sql = 'UPDATE Grades SET grade = 400 WHERE grade<400'
cursor.execute(sql)
connect.commit()
# 6 刪除學號小於5的人的信息
sql = 'DELETE FROM Grades WHERE num <5'
cursor.execute(sql)
connect.commit()
#7 查找姓 張的人的全部信息
sql = "SELECT * FROM Grades WHERE name like '張%'"
rs = cursor.execute(sql)
for x in rs:
    print(x)
connect.commit()
# 8 查詢全部人的成績，按照成績從高到低排列
sql = 'SELECT name,grade FROM Grades ORDER BY grade DESC'
rs = cursor.execute(sql)
rs = list(rs)
print(rs)
connect.commit()

# 9 查詢全部人的成績，按照名次從小到大排列
sql = 'SELECT name,grade FROM Grades ORDER BY rank ASC'
rs = cursor.execute(sql)
rs = list(rs)

print(rs)
connect.commit()

 

1.建立新表
create table tabname(col1 type1 [not null] [primary key],col2 type2 [not null],..)

2.刪除表
drop table tabname

3.查詢：select * from table1 where 範圍

4.插入：insert into 表名(字段名1,字段名2) values(值1,值2)

5.刪除：delete from table1 where 範圍

6.修改：update 表名 set 修改的字段名=修改的字段值 where 範圍

7.查找：select * from table1 where field1 like ’%value1%’ N%匹配以N開頭     %N匹配以N結尾   %N%匹配包含N  
	[a,b]% 以a或b開頭     %[a,b]以a或b結尾

	select * from table1 where field1 like 'z_'以z開頭且匹配以後一個字符

	升序輸出數據記錄
	select * from table_name order by field asc
	降序輸出數據記錄
	select * from table_name order by field desc

9.總數：select count (*) from table_name;