批量更新

拼接的SQL语句类似于这种：

* UPDATE book 
*     SET book_id = CASE id 
*         WHEN 1 THEN 3 
*         WHEN 2 THEN 4 
*         WHEN 3 THEN 5 
*     END, 
*     name = CASE id 
*         WHEN 1 THEN 'New Title 1'
*         WHEN 2 THEN 'New Title 2'
*         WHEN 3 THEN 'New Title 3'
*     END
* WHERE id IN (1,2,3)   

book 表名 book_id name 更新字段

CASE id WHEN 1 THEN 3
id为判断条件
WHEN 1为id==1
THEN 3为book_id更新成3