XML类型

MogDB=# CREATE TABLE xmltest ( id int, data xml );
MogDB=# INSERT INTO xmltest VALUES (1, 'one');
MogDB=# INSERT INTO xmltest VALUES (2, 'two');
MogDB=# SELECT * FROM xmltest ORDER BY 1;
 id | data
----+--------------------
1 | one
2 | two
(2 rows)
MogDB=# SELECT xmlconcat('', NULL, '');
xmlconcat
(1 row)
MogDB=# SELECT xmlconcat('', NULL, '');
xmlconcat
(1 row)