SQL: "IN" Function
The IN function helps reduce the need to use multiple OR conditions.
译：IN函数有助于减少OR条件的复合使用。
The syntax for the IN function is:
译：IN函数的语法：
SELECT columns
FROM tables
WHERE column1 in (value1, value2, .... value_n);
原文：http://www.cnblogs.com/sunpx/p/4769125.html