1.LISTAGG()函数作为普通函数使用时就是查询出来的结果列转为行
SELECT LISTAGG ( NAME_CHS, ',' ) within GROUP ( ORDER BY ROWNUM ) name FROM GSPUSER WHERE ROWNUM <= 10
2.LISTAGG()作为分组函数使用
例如,把每个班组下面的人员拼接成一行
SELECT b.MOMTEAMNAME, LISTAGG ( g.NAME_CHS, ',' ) WITHIN GROUP ( ORDER BY b.MOMTEAMNAME ) res FROM DGMOMPTDGMOMGLHQYBZGL b LEFT JOIN DGMOMPTABOUTUSERS u ON b.ID = u.PARENTID LEFT JOIN GSPUSER g ON u.MOMEMPLOYEEID = g.ID WHERE b.MOMDATASTATE = 0 AND u.MOMDATASTATE = 0 GROUP BY b.MOMTEAMNAME
3.LISTAGG()做分析函数使用
例如,查询每个班组下面有哪些人,统计每组人数量
SELECT MOMTEAMNAME,RES,COUNT FROM( SELECT b.MOMTEAMNAME, LISTAGG ( g.NAME_CHS, ',' ) WITHIN GROUP ( ORDER BY b.MOMTEAMNAME ) over(partition by b.MOMTEAMNAME) res, count(g.NAME_CHS) over(partition by b.MOMTEAMNAME) count, row_number() over(partition by b.MOMTEAMNAME ORDER BY ROWNUM) rn FROM DGMOMPTDGMOMGLHQYBZGL b LEFT JOIN DGMOMPTABOUTUSERS u ON b.ID = u.PARENTID LEFT JOIN GSPUSER g ON u.MOMEMPLOYEEID = g.ID WHERE b.MOMDATASTATE = 0 AND u.MOMDATASTATE = 0 ) WHERE rn = 1
附:高级用法
listagg(XXX,’,’) within GROUP (order by XXX) over (partition by XXX) rank
示例
with temp as( select 500 population, '中国' nation ,'江苏' city from dual union all select 1500 population, '中国' nation ,'上海' city from dual union all select 500 population, '中国' nation ,'北京' city from dual union all select 1000 population, '美国' nation ,'纽约' city from dual union all select 500 population, '美国' nation ,'波士顿' city from dual union all select 500 population, '日本' nation ,'东京' city from dual ) select population, nation, city, listagg(city,',') within GROUP (order by city) over (partition by nation) rank from temp复制