返回一個設(shè)定值(含子字符串分隔字符串。,。字符)由那些在設(shè)置位的相應(yīng)位的字符串。str1對應(yīng)于位0,str2至位1,以此類推。NULL值在str1,str2,...不添加到結(jié)果。
SQL> SELECT MAKE_SET(1,'a','b','c'); +---------------------------------------------------------+ | MAKE_SET(1,'a','b','c') | +---------------------------------------------------------+ | a | +---------------------------------------------------------+ 1 row in set (0.00 sec)