Shulou(Shulou.com)06/01 Report--

The wmsys.wm_concat function, which functions as a', 'link character

Examples are as follows:

SQL > create table idtable (id number,name varchar2 (30))

Table created

SQL > insert into idtable values (10)

1 row inserted

SQL > insert into idtable values (10gramme bc')

1 row inserted

SQL > insert into idtable values (10)

1 row inserted

SQL > insert into idtable values (20 minutes later)

1 row inserted

SQL > insert into idtable values (20 ~ (th))

1 row inserted

SQL > insert into idtable values (20m MN')

1 row inserted

SQL > select * from idtable

ID NAME

10 ab

10 bc

10 cd

20 hi

20 ij

20 mn

6 rows selected

SQL > select id,wmsys.wm_concat (name) name from idtable

2 group by id

ID NAME

-

10 ab,bc,cd

20 hi,ij,mn

SQL > select id,wmsys.wm_concat (name) over (order by id) name from idtable

ID NAME

-

10 ab,bc,cd

10 ab,bc,cd

10 ab,bc,cd

20 ab,bc,cd,hi,ij,mn

20 ab,bc,cd,hi,ij,mn

20 ab,bc,cd,hi,ij,mn

6 rows selected

SQL > select id,wmsys.wm_concat (name) over (order by id,name) name from idtable

ID NAME

-

10 ab

10 ab,bc

10 ab,bc,cd

20 ab,bc,cd,hi

20 ab,bc,cd,hi,ij

20 ab,bc,cd,hi,ij,mn

6 rows selected

Personally, I find this usage more interesting.

SQL > select id,wmsys.wm_concat (name) over (partition by id) name from idtable

ID NAME

-

10 ab,bc,cd

10 ab,bc,cd

10 ab,bc,cd

20 hi,ij,mn

20 hi,ij,mn

20 hi,ij,mn

6 rows selected

SQL > select id,wmsys.wm_concat (name) over (partition by id,name) name from idtable

ID NAME

-

10 ab

10 bc

10 cd

20 hi

20 ij

20 mn

6 rows selected

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