mysql extract year from date format
Solution 1:
Since your subdateshow is a VARCHAR column instead of the proper DATE, TIMESTAMP or DATETIME column you have to convert the string to date before you can use YEAR on it:
SELECT YEAR(STR_TO_DATE(subdateshow, "%m/%d/%Y")) from table
See http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_str-to-date
Solution 2:
SELECT EXTRACT(YEAR FROM subdateshow) FROM tbl_name;