符号 | 功能 |
---|---|
^ | 匹配一行的开头 |
$ | 匹配线的末尾 |
. | 匹配任何角色 |
\ S | 匹配空白 |
\ S | 匹配任何非空白字符 |
* | 重复一个字符零次或多次 |
*? | 重复一个字符零次或多次(非贪婪) |
+ | 重复一次或多次角色 |
+? | 重复一次或多次角色(非贪婪) |
[AEIOU] | 匹配列出的集合中的单个字符 |
[^ XYZ] | 匹配不在列出的集合中的单个字符 |
[A-Z0-9] | 字符集可以包括范围 |
( | 指示字符串提取的开始位置 |
) | 指示字符串提取结束的位置 |
conn = sqlite3.connect('trackdb.sqlite')
cur = conn.cursor()
# Make some fresh tables using executescript()
cur.executescript('''
DROP TABLE IF EXISTS Artist;
DROP TABLE IF EXISTS Album;
DROP TABLE IF EXISTS Track;
DROP TABLE IF EXISTS Genre;
CREATE TABLE Artist (
id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
name TEXT UNIQUE
);
CREATE TABLE Genre (
id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
name TEXT UNIQUE
);
CREATE TABLE Album (
id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
artist_id INTEGER,
title TEXT UNIQUE
);
CREATE TABLE Track (
id INTEGER NOT NULL PRIMARY KEY
AUTOINCREMENT UNIQUE,
title TEXT UNIQUE,
album_id INTEGER,
genre_id INTEGER,
len INTEGER, rating INTEGER, count INTEGER
);
''')
cur.execute('''INSERT OR IGNORE INTO Artist (name)
VALUES ( ? )''', ( artist, ) )
cur.execute('SELECT id FROM Artist WHERE name = ? ', (artist, ))
artist_id = cur.fetchone()[0]
cur.execute('''INSERT OR IGNORE INTO Album (title, artist_id)
VALUES ( ?, ? )''', ( album, artist_id ) )
cur.execute('SELECT id FROM Album WHERE title = ? ', (album, ))
album_id = cur.fetchone()[0]
cur.execute('''INSERT OR IGNORE INTO Genre (name) VALUES ( ? )''',(genre, ))
cur.execute('SELECT id FROM Genre WHERE name = ?', (genre, ))
# print('genre_id',cur.fetchone())
genre_id = cur.fetchone()[0]
cur.execute('''INSERT OR REPLACE INTO Track
(title, album_id, len, rating, count, genre_id)
VALUES ( ?, ?, ?, ?, ?, ?)''',
( name, album_id, length, rating, count, genre_id ) )
conn.commit()
cur.execute('''SELECT Track.title, Artist.name, Album.title, Genre.name
FROM Track JOIN Genre JOIN Album JOIN Artist
ON Track.genre_id = Genre.ID and Track.album_id = Album.id
AND Album.artist_id = Artist.id
ORDER BY Artist.name LIMIT 3''')
print('result',cur.fetchone())