creating user in mysql using java

问题

In MySQL command line client after logging in as root, I typed:

connect mydb;
grant all privileges on mydb.* to 'admin'@'localhost' identified by 'pass';

Now within Java, I succesfully connect to the db using the admin userid using drivers.

 Statement put=connect.createStatement();

 //**WORKS succesfully**
 put.execute("insert into mydb.emp values(100,joe)");   

 //**does NOT work**
 put.execute("grant all privileges on mydb.* to 'john'@'localhost' identified by 'pass'"); 

Why does an insert command work but grant command never work through Java?

Please help.

回答1:

put.execute(MySQL query) 

in here you can execute only MySQL query but

grant all privileges on mydb.* to 'admin'@'localhost' identified by 'pass';

Not a MySQL query it is just a command for MySQL.

回答2:

You just forgot the quotation marks.

回答3:

Try following

put.execute("grant all privileges on mydb.* to 'john'@'localhost' identified by 'pass'"); 

And also make sure you have ExtendedAnsiSQL flag to 1.

回答4:

I tried working with query parameters - what I found somewhat confusing is that you have to put a blank between the parameter and @localhost for example - this here worked for me: (jpaEm is a JpaEntityManager here)

// Create user
String sql = "CREATE USER ? @localhost";
Query query = jpaEm.createNativeQuery(sql);
query.setParameter(1, user.getUserName());
jpaEm.getTransaction().begin();
query.executeUpdate();
jpaEm.getTransaction().commit();

// Set password
sql = "SET PASSWORD FOR ? @localhost = PASSWORD(?)";
query = jpaEm.createNativeQuery(sql);
query.setParameter(1, user.getUserName()); 
query.setParameter(2, user.getPassword());
jpaEm.getTransaction().begin();
query.executeUpdate();
jpaEm.getTransaction().commit();

来源：https://stackoverflow.com/questions/17567981/creating-user-in-mysql-using-java