Android 常用代码---SQL

1	创建表
权限
代码		CREATE TABLE songs(
id  INTEGER,
name  TEXT,
genre  TEXT,
rate  REAL,
some_raw_data BLOB
);
2	使用其它表的数据创建表
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代码		SELECT *  INTO rockssongs
FROM songs WHERE genre ='rock';
3	计数示例
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代码		SELECT COUNT(DISTINCT student_city) AS total
FROM students;
4	删除行
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代码		DELETE FROM songs
WHERE rating< 5;
5	删除表
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代码		DROP TABLE"bad_songs";
6	左联接示例
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代码		SELECT students.name
FROM students LEFT JOIN math_class
ON students.id = math_class.student_id
WHERE math_class.grade > 5;
7	内部联接示例
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代码		SELECT DISTINCT students.id, students.name
FROM students INNER JOIN math_class ON students.id = math_class.student_id;
8	插入示例
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代码		INSERT INTO albums(ambum_id, artist_name, album_name)
VALUES('12345', 'David Bowie','Ziggy Stardust');
9	更新表
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代码		UPDATE songs SET already_listened ="yes"
WHERE genre = "rock";