关于substring中 str>2?2:0的用法

 String str="";

String test=str.substring(0,str>2?2:0)

1.select max(to_number(ID)) seq from test_table

2.update test_tab set (qymc,zch,djjg,gxdw) = (select entname,regno,REGORG,LOCALADM from sl_qyhznr) where id='1'

3.select NAME,id,to_char(DATE,'YYYY-MM-DD')  DATE  from table_test