jdbc cannot connect to postgresql database - Stack Overflow

Question

• When using jdbc to connect to the postgresql database, the following error occurs:

org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: 
### Error querying database.  Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (????????: ?????? "uav_test " ??????)
### The error may exist in file [G:\Uav\NewMavenDemo\target\classes\mapper\UserMapper.xml]
### The error may involve UserMapper.getUserInfo
### The error occurred while executing a query
### Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (????????: ?????? "uav_test " ??????)
    at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:79)
    at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:447)
    at com.sun.proxy.$Proxy27.selectList(Unknown Source)

• Key error message: Cannot create PoolableConnectionFactory (????????: ?????? "uav_test " ??????)

• The connection parameters are as follows:

#Postgresql  
driver=org.postgresql.Driver
url=jdbc:postgresql://localhost:5432/uav_test 
username=postgres
password=root
dialect=postgresql

• There is no problem when I change the postgresql database to use mysql. The parameters for mysql:

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mysql
username=root
password=root
dialect=mysql 

• I don’t quite understand why this happens

Answer 1

• Filling in the hole;
  After working on it for a long time, it turns out that the connection name uav_test was mistaken for the database name, and the real error message is this: Fatal error: The database "uav_test" does not exist, maybe because of encoding There is a format problem and Chinese characters cannot be displayed, making it impossible to find errors.

• Only rookies make mistakes

Answer 2

It should be that the sql statement is written incorrectly,