Connect “computer-database-jpa” Play 2.1 sample application with MySQL

问题

I'm playing with computer-database-jpa (Java) Play Framework 2.1 sample application. Everything works fine when I'm using H2 in memory database but I had problems when I want to connect the application with MySQL.

Some one had the same problem (Help wanted getting sample app connected to MySQL) but there was no solution.

I've added mysql-connector (Build.scala):

val appDependencies = Seq(
  ....
  "mysql" % "mysql-connector-java" % "5.1.18"
)

and edited application.conf:

db.default.url="jdbc:mysql://password:user@localhost/my-database"
db.default.driver=com.mysql.jdbc.Driver

When I start the applications and apply 1.sql (evolution script) I get an error:

You have an error in your SQL syntax; check the manual that corresponds to
your MySQL server version for the right syntax to use near 'sequence company_seq
start with 1000' at line 1 [ERROR:1064, SQLSTATE:42000]

Does anyone have an idea how to solve the problem?

回答1:

I've found the solution - https://github.com/opensas/openshift-play2-computerdb.

Syntax used in evolution scripts isn't conform with MySQL:

List of changes needed to port computer-database sample app from H2 to mysql

conf/evolutions/default/1.sql

• added engine=innodb, to enable referential integrity
• replaced sequences with autoincrement for id fields
• replaced 'SET REFERENTIAL_INTEGRITY' command with 'SET FOREIGN_KEY_CHECKS'
• replaced timestamp fields with datetime

conf/evolutions/default/2.sql

• splitted the computer data between 2.sql and 3.sql file (avoid bug in evolutions running on mysql)

models/Models.scala

• removed 'nulls last' from Computer.list sql query
• modified Computer.insert to skip id field (because is auto-assigned by mysql)

Because I was playing with Java and not Scala version I'd to change Company.java and Computer.java files. I've added @GeneratedValue annotation:

@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
public Long id;

Here you can find modified evolution scripts: https://github.com/opensas/openshift-play2-computerdb/tree/master/conf/evolutions/default

来源：https://stackoverflow.com/questions/15783586/connect-computer-database-jpa-play-2-1-sample-application-with-mysql