如何使用JDBC / Hibernate基于用户输入数据生成“创建表”查询？

Question

Assume if we are giving the query data in a csv file as such below:

Emp_Id, Emp_Name, Address

Now, the query (Mysql) like below should be generated and processed.

Create TABLE Emp_tbl(
   Emp_id INT NOT NULL,
   Emp_Name VARCHAR(100) NOT NULL,
   Address VARCHAR(400) NOT NULL,
   PRIMARY KEY ( Emp_id )
);

Thanks in Advance!!

Answer 1

You can achieve it by jdbc:

String sql_stmt = "Create TABLE Emp_tbl(
   Emp_id INT NOT NULL,
   Emp_Name VARCHAR(100) NOT NULL,
   Address VARCHAR(400) NOT NULL,
   PRIMARY KEY ( Emp_id )
);";

public void createTable(String sql_stmt) throws SQLException {

    // your connection code
    statement = connection.createStatement();

    statement.executeUpdate(sql_stmt);
}

Also here is about map dynamically created table in hibernate :

It can be done dynamically, but it's somewhat messy:

You'll need to dynamically alter Hibernate's Configuration object before SessionFactory is built. If you're using Spring, this can be done by overriding postProcessAnnotationConfiguration() method of AnnotationSessionFactoryBean; otherwise you'll just need to do it using your Configuration object prior to invoking buildSessionFactory() on it.

If you need to do this without application restart, you're looking at either rebuilding your SessionFactory (which means your users will have to wait until that's done) or using a separate SessionFactory instance specifically dedicated to your custom classes (which is next to impossible if your custom classes need to reference your built-in classes).

You can get access to class / table mappings via configuration.getMappings(). You will then need to create a new table mapping via Table API and add it to configuration via addTable(). Same thing will have to be done with PersistentClass which represents a class mapping. If you're using the same class to represent multiple entities (eg map multiple tables) make sure to use unique entity names for each. You'll have to do this (alter the configuration) on every app restart.