1, string link --CONCAT ()
SELECT CONCAT(name,'=>',score) FROM tb_name
2, mathematical functions:
AVG、SUM、MAX、MIN、COUNT;
3, text processing functions:
TRIM、LOCATE、UPPER、LOWER、SUBSTRING
4, the operator:
+、-、*、\
5, time function:
DATE()、CURTIME()、DAY()、YEAR()、NOW().....