在日常SinoDB运维工作中，发现一个很便捷很强大的函数DBINFO，通过SQL语句和function等获取数据库相关信息，结合运维和开发工作可带来很多便利，介绍给大家。
常用的几种方式如下：
1.获取dbspace信息：
>select dbinfo(‘dbspace’,partnum) from systables where tabname=‘h_history’;
(expression) datadbs
2.获取当前连接数据库的会话信息：
select dbinfo(‘sessionid’) from sysmaster:sysdual;
(expression) 1739808
3.获取时区信息：
select dbinfo(‘get_tz’) from sysmaster:sysdual;
(expression) Asia/Shanghai
4.获取当前的数据库名：
select dbinfo(‘dbname’) from sysmaster:sysdual;
(expression) testdb
5.获取DML和SELECT作用于表返回的条数
dbinfo(‘sqlca.sqlerrd2’)
应用例子：
CREATE FUNCTION sel_rows ()
RETURNING INT;
DEFINE nrows INT;
select * FROM t1 into temp tmp_t1 with no log;
LET nrows = DBINFO(‘sqlca.sqlerrd2’);
RETURN nrows;
END FUNCTION;
执行函数：
execute function sel_rows();
(expression) 3
6.获取数据库当前时间：
select dbinfo(‘UTC_TO_DATETIME’,sh_curtime) from sysmaster:sysshmvals;
(expression) 2021-08-08 15:16:50
比较全的用法，可参考以下表格：
| Arguments | Information Returned | Topic |
|---|---|---|
| (‘dbhostname’) | The host name of the database server to which a client application is connected | Using the ‘dbhostname’ Option |
| (‘dbname’) | The identifier of the database to which a client application is connected | Using the ‘dbname’ Option |
| (‘dbspace’ tblspace_num) | The name of a dbspace corresponding to a tblspace number | Using the (‘dbspace’, tblspace_num) Option |
| (‘get_tz’) | The time zone of the session, $TZ, as specified as a string by the client. | Using the ‘get_tz’ Option |
| (‘serial8’) | The last SERIAL8 value inserted in a table | Using the ‘serial8’ and ‘bigserial’ options |
| (‘bigserial’) | The last BIGSERIAL value inserted in a table | Using the ‘serial8’ and ‘bigserial’ options |
| (‘sessionid’) | The session ID number of the current session | Using the ‘sessionid’ Option |
| (‘cdrsession’) | Whether a thread is performing an Enterprise Replication operation | Using the ‘cdrsession’ option |
| (‘sqlca.sqlerrd1’) | The last SERIAL value inserted in a table | Using the ‘sqlca.sqlerrd1’ Option |
| (‘sqlca.sqlerrd2’) | The number of rows processed by SELECT, INSERT, DELETE, UPDATE, EXECUTE PROCEDURE, and EXECUTE FUNCTION statements | Using the ‘sqlca.sqlerrd2’ Option |
| (‘utc_current’) | The current UTC time value (as an integer number of seconds since 1970-01-01 00:00:00+00:00) when the SQL statement began to execute. | Using the ‘utc_current’ Option |
| (‘utc_to_datetime’, table.column) | The DATETIME value corresponding to a specified integer column containing a UTC time value (as an integer number of seconds since 1970-01-01 00:00:00+00:00). | Using the ‘utc_to_datetime’ Option |
| (‘utc_to_datetime’, utc_value) | The DATETIME value corresponding to a specified UTC time value (as an integer number of seconds since 1970-01-01 00:00:00+00:00). | Using the ‘utc_to_datetime’ Option |
| (‘version’, ‘parameter’) | Type of the database server and its release version to which the client application is connected. (The call to DBINFO fails with an error if no parameter specifies a format for the version information.) | Using the ‘version’ Option |