Could not open JPA EntityManager for transaction; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection You can try to increase db connection pool in application config file, for example: I have tried to change the hibernate.dialect value in the hibernate.cfg.xml file to org.hibernate.dialect.PostgreSQL82Dialect (since the value I was using was deprecated). But no luck there. I took the query from the exception and ran it into a SQL console. The query does not work. Although if I remove the parenthesis, it does. hibernate.cfg.xml. I have problem with hibernate with connection to database always have Exception Access denied for user 'root'@'localhost' (using password: YES) even if i have user xx not root. My hibernate.cfg.xml is: I've had similar problem. There was plenty of errors: "data exception: string data, right truncation". The resolution was to specify size of big fields. Without that fields will be limited to default size. But that is not all. HSQL doesn't automatically updates database schema. So changes will not apply util you recreate database. Package org.springframework.orm.hibernate5. Package providing integration of Hibernate 5.x with Spring concepts. Contains an implementation of Spring's transaction SPI for local Hibernate transactions. This package is intentionally rather minimal, with no template classes or the like, in order to follow Hibernate recommendations as closely as This is a bit of a problem with Hibernate's JDBCException class: It stores context such as the SQL String but doesn't include it in the exception message As a consequence, I've added that context explicitly when translating those exceptions: directly, without adding another exception to the chain. .

jdbc exception on hibernate data access