How to fix "Can't infer the SQL type to use for an instance of enum" error when inserting enum value?

Question

I'm trying to develop a simple CRUD-application,that receives data in the JSON-format,processes it, and puts it in a PostgreSQL table. One of the fields in the table, gender, is represented by an enumeration.

Here I am trying to add an entry using the Postman:

{
    "employeeId": 1,
    "firstName": "Ada",
    "lastName": "Lovelace",
    "departmentId": 3,
    "jobTitle": "Senior",
    "gender": "FEMALE",
    "dateOfBirth": "1815-12-10"
}

Here is the DAO-layer code:

@Override
public void addEmployee(Employee employee) {
    String sql = "INSERT INTO employees(employee_id, first_name, last_name, department_id, job_title, gender, date_of_birth) VALUES (?, ?, ?, ?, ?, CAST(? AS gender), ?)";
    getJdbcTemplate().update(sql, employee.getEmployeeId(), employee.getFirstName(), employee.getLastName(),
            employee.getDepartmentId(), employee.getJobTitle(), employee.getGender(), employee.getDateOfBirth());
}

As a result, I get: 500 Internal Server Error and

"PreparedStatementCallback; bad SQL grammar [INSERT INTO employees(employee_id, first_name, last_name, department_id, job_title, gender, date_of_birth) VALUES (?, ?, ?, ?, ?, CAST(? AS gender), ?)]; nested exception is org.postgresql.util.PSQLException: Can't infer the SQL type to use for an instance of com.way.dto.Gender. Use setObject() with an explicit Types value to specify the type to use."

Answer 1

What SQL type is the gender field?

In stead of passing in the enum, you could also pass in the string equivalent, for example employee.getGender().name() or employee.getGender().toString()