How to prevent the Hibernate schema from being generated automatically

This is my code:
The tables in sql server:

create table Department(
Department_ID int identity primary key,
Department_Name varchar(20) not null,
);

create table Employee(
Employee_ID int identity primary key,
Employee_Name varchar(20) not null,
Department_ID int not null
);
alter table Employee add constraint FK_Employee foreign key(Department_ID) references dbo.Department;

Department.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="com.yp.entity2">

	<class name="Department" table="Department">

		<id name="id" column="Department_ID">

			<generator class="native"/>

		</id>
		
		<property name="name" column="Department_Name" length="20" />
		
		<set name="emps" inverse="true" lazy="true">

			<key column="Department_ID"/>

			<one-to-many class="Employee"/>

		</set>
				
	</class>

</hibernate-mapping>

Employee.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="com.yp.entity2">

	<class name="Employee" table="Employee">

		<id name="id" column="Employee_ID">

			<generator class="native"/>

		</id>
		
		<property name="name" column="Employee_Name" length="20"/>
		
		<many-to-one name="dept" class="Department" column="Department_ID"/>
				
	</class>

</hibernate-mapping>

Entity class

public class Employee {

	private Integer id;
	private String name;
	private Department dept;
	
	//getter,setter
}

public class Department {

	private Integer id;
	private String name;
	private Set<Employee> emps = new HashSet<>();
	//getter,setter
}

My problem is I have already created the foreign key named “FK_Employee” in Employee table, but the client program still generates a new foreign key named “FKj9uwop98sf53kym2p5719ajt2” in table Employee.

What should I do so the client program does not need to change the table structure in sql server, Did I missed something in Employee.hbm.xml, like declare the foreign key name in mapping file?

but the client program still generates a new foreign key named “FKj9uwop98sf53kym2p5719ajt2” in table Employee.

Just set the hibernate.hbm2ddl.auto property to none instead of update since you don’t need the DB schema to be generated for you.