XML Type

MogDB supports the XML type. The following is an example:

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)

NOTE:

• This function is disabled by default. To use this function, you need to use the build.sh script to compile the database again and add the -with-libxml parameter to the ./configure configuration parameter.
• Before compilation, you need to run the yum install -y libxml2-devel command. Otherwise, the "configure: error: library 'xml2' (version >= 2.6.23) is required for XML support" error will be reported.
• Before compilation, you need to add the dependency/operating system environment/libobs/comm/lib in the binary file of the third-party library to the system environment variable LD_LIBRARY_PATH. Otherwise, an error message is displayed, indicating that libiconv.so does not exist.