android SQL

 

/*

* SQL

* 

*/

 

 

//***创建表

 

CREATE TABLE songs(

    id  INTEGER,

    name  TEXT,         

    genre  TEXT, 

    rate  REAL,     

    some_raw_data BLOB      

);

 

//***使用其他表的数据创建表

 

SELECT *  INTO rockssongs

FROM songs WHERE genre ='rock';

 

//***计数示例

 

SELECT COUNT(DISTINCT student_city) AS total

FROM students;

 

//***删除行

 

DELETE FROM songs

WHERE rating< 5;

 

//***删除表

 

DROP TABLE"bad_songs";

 

//***左联接示例

 

SELECT students.name 

FROM students LEFT JOIN math_class

    ON students.id = math_class.student_id 

WHERE math_class.grade > 5;

 

//***内部联接示例

 

SELECT DISTINCT students.id, students.name

FROM students INNER JOIN math_class ON students.id = math_class.student_id;

 

//***插入示例

 

INSERT INTO albums(ambum_id, artist_name, album_name)

VALUES('12345', 'David Bowie','Ziggy Stardust');

 

//***更新表

 

UPDATE songs SET already_listened ="yes"

WHERE genre = "rock";