oracle和mysql的几个区别

文档https://docs.oracle.com/en/database/oracle/oracle-database/18/sqlrf/LISTAGG.html#GUID-B6E50D8E-F467-425B-9436-F7F8BF38D466

rownum = 1 limit 1
sequence.currval SELECT current_value FROM sequence where name = tablename
seq.nextval nextval('seq')
drop sequence name delete from sequence where name = tablename
create sequence insert into sequence

nvl ifnull
to_char('20201212','yyyyMMdd') date_format('20201212','%Y-%m-%d')

a||'b' concat(a,'b')
sysdate now() CURDATE()//当前日期 CURTIME() //当前时间
instr(a,'b',1,1)>0 locate('b',a)>0
delete from table a where exists(xxx where a.col = b.col)
delete a from table a where exists(xxx where a.col = b.col)

wm_concat(col) group_concat(col)
select 1 from a,b where a.col = b.col(+) select 1 from a left join b on a.col = b.col

order by nlssort(NAMECN,'NLS_SORT=SCHINESE_PINYIN_M') order by CONVERT( NAMECN USING gbk ) COLLATE gbk_chinese_ci desc
oracle分页查询设置maxsize startsize 时分页会乱，需要加一个主键排序
to_date(:processdateStart,'yyyyMMdd') STR_TO_DATE(:processdateStart,'%Y%m%d')