Mysql – Could not commit JPA transaction while working with post request

I’m attempting to send a post request with an image attachment and employee details in json format. For ImageData and Employee, I have distinct tables. I am able to store image data with my code, but not employee data.The error message "Could not commit JPA transaction" is displayed.
Here I am sharing my code details

#Post Request
@PostMapping("/create")
    public Employee tempCreateEmployee(
            @RequestParam("json") String json,
            @RequestParam("file") MultipartFile file
    ) throws CustomException {
        try {

            ObjectMapper objectMapper = new ObjectMapper();
            logger.info("data received as string");

            Employee employee = objectMapper.readValue(json, Employee.class);
            logger.info(employee.toString());

            logger.info("Received employee data: {}", employee);
            
            int imageId=fileService.uploadImageFile(file);
            logger.info("file processing successful");
            
            employee.setImageid(imageId);
            logger.info(employee.toString());
           
            return employeeService.save(employee);
        } catch (Exception ex) {
           
            throw new CustomException("Employee object not created");
        }
    }

Service method for uploading image

public int uploadImageFile(MultipartFile file) throws IOException {
        ImageData imageData= filesRepo.save(ImageData.builder()
                .name(file.getOriginalFilename())
                .type(file.getContentType())
                .id(filesRepo.findAll().size()+1)
                .image_filedata(ImageUtils.compressImage(file.getBytes())).build());
        
       
        return imageData.getId();

    }

Employee Model class:

package com.SpringTask.SpringTask.Models;

import com.SpringTask.SpringTask.Encryption.Encrypt;
import com.fasterxml.jackson.annotation.JsonFormat;
import jakarta.persistence.*;
import jakarta.validation.constraints.*;
import jdk.jfr.DataAmount;


import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.Date;


import lombok.*;

@AllArgsConstructor
@NoArgsConstructor
@Builder
@Setter
@Getter
@Data
@Entity
@Table(name="tableEmployees")

public class Employee {
    @Id
    @GeneratedValue
    public Integer id;


    public String firstName;

  
    public String lastName;

    
    public String address;

    
    public String email;


    
    public int phoneNumber;

  

    private int imageid;

   }

ImageData model class:

package com.SpringTask.SpringTask.Models;

import jakarta.persistence.*;
import jakarta.persistence.Table;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.*;
import lombok.NoArgsConstructor;
import org.hibernate.engine.internal.Cascade;

import java.util.Arrays;


@Entity
@Table(name = "tableImageData")
@Builder(toBuilder = true)
@Data
@AllArgsConstructor
@NoArgsConstructor
@Setter
@Getter

public class ImageData {
    @Id
    private int id;

    private String name;
    private String type;

    @Lob
    @Column(name = "image_filedata", columnDefinition = "LONGBLOB")
    private byte[] image_filedata;
    
}

I’ve tried debugging , but every time same issue appears. I have verified my database setup and code logic.
Could not commit JPA transaction means?