Cannot connect to the database. –Error connecting to database.

环境 ： Ubuntu 16

报错信息 ：
Cannot connect to the database.
–Error connecting to database.

登录postgresql数据库
#su - postgresql
查看postgresql日志
$cat logfile

问题二 Error connecting to database.

重启虚拟机之后，zabbix server界面打不开了

解决办法：
cat /var/log/zabbix/zabbix_server.log

重启数据库

问题三、 Error connecting to database.

解决办法 ：

#su - postgres      #进入数据库
$ cat logfile       #查看数据库日志
ERROR:  relation "users" does not exist at character 20
STATEMENT:  select userid from users limit 1
ERROR:  relation "users" does not exist at character 20
STATEMENT:  select userid from users limit 1
ERROR:  relation "users" does not exist at character 20
STATEMENT:  select userid from users limit 1

数据库报错信息： ERROR: relation “users” does not exist at character 20

zabbix日志报错信息 ：

 38468:20200130:195744.484 using configuration file: /etc/zabbix/zabbix_server.conf
 38468:20200130:195744.491 [Z3005] query failed: [0] PGRES_FATAL_ERROR:ERROR:  relation "users" does not exist
LINE 1: select userid from users limit 1
                           ^
 [select userid from users limit 1]
 38468:20200130:195744.491 cannot use database "zabbix": database is not a Zabbix database

解决办法 ：
删除数据库，重新创建。

postgres=# drop database zabbix；
DROP DATABASE
postgres=# drop user zabbix;
DROP ROLE
postgres@ubuntu:~$  createuser --pwprompt zabbix
Enter password for new role: 
Enter it again: 
postgres@ubuntu:~$ createdb -O zabbix zabbix
postgres@ubuntu:~$