SQL-To-JAVA

Convert MySQL CREATE TABLE statements to Java entity classes following framework conventions. Use when converting SQL DDL to Java entity definitions, generating ORM models from database schemas, or creating JPA/MyBatis-Plus entity classes from MySQL tables. Supports MySQL to Java type mapping, snake_case to camelCase conversion, and automatic annotation generation with MyBatis-Plus and JPA annotations.

Coder-MYJ@coder-myj

Install

openclaw skills install @coder-myj/sql-to-java

SQL to Java Entity

Quick Start

Convert a MySQL CREATE TABLE statement to a Java entity class:

Parse the CREATE TABLE statement to extract table name, columns, and constraints
Map each MySQL column type to corresponding Java type
Convert snake_case column names to camelCase field names
Generate entity class with @TableName, @TableId, and JPA annotations
Generate getter/setter methods

Configuration

Before generating the entity class, determine the following:

Package name: Ask the user for the target package (e.g., com.example.entity)
Base class: Ask if the entity should extend a base class
Annotation style: Confirm whether to use MyBatis-Plus annotations (default) or JPA annotations

If the user doesn't specify, use sensible defaults based on the project context.

Type Mapping

For complete MySQL to Java type mappings, see type_mappings.md.

Quick Reference

MySQL	Java	Notes
`INT`	`Integer`
`BIGINT`	`Long`
`VARCHAR`	`String`
`TEXT`	`String`
`DATETIME`	`LocalDateTime`	java.time.LocalDateTime
`TIMESTAMP`	`LocalDateTime`	java.time.LocalDateTime
`TINYINT(1)`	`Integer`
`DECIMAL`	`BigDecimal`	java.math.BigDecimal

Column Name Conversion

Convert snake_case to camelCase:

text

user_name    → userName
created_at   → createdAt
user_id      → userId
is_active    → isActive

Class name conversion (PascalCase):

text

user_info    → UserInfo
order_detail → OrderDetail

Annotation Generation

MyBatis-Plus Annotations

Constraint	Annotation
Table name	`@TableName("table_name")`
Primary key	`@TableId(type = IdType.AUTO)`
Column name	`@TableField("column_name")` (only if different from field name)
Not mapped	`@TableField(exist = false)`

JPA Annotations (if needed)

Constraint	Annotation
Primary key	`@Id`
Auto increment	`@GeneratedValue(strategy = GenerationType.IDENTITY)`
Column name	`@Column(name = "column_name")`
Not null	`@Column(nullable = false)`
Unique	`@Column(unique = true)`
Length	`@Column(length = 50)`

Example

Input

sql

CREATE TABLE `user_info` (
    `id` bigint unsigned NOT NULL AUTO_INCREMENT,
    `name` varchar(50) NOT NULL,
    `age` int DEFAULT NULL,
    `email` varchar(100) NOT NULL,
    `salary` decimal(10,2) DEFAULT NULL,
    `description` text,
    `created_at` datetime DEFAULT CURRENT_TIMESTAMP,
    `is_active` tinyint(1) DEFAULT '1',
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='User Table';

Output

java

package com.example.model;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;

import java.math.BigDecimal;
import java.time.LocalDateTime;

@TableName("user_info")
public class UserInfo {

    @TableId(type = IdType.AUTO)
    private Long id;

    private String name;

    private Integer age;

    private String email;

    private BigDecimal salary;

    private String description;

    private LocalDateTime createdAt;

    private Integer isActive;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public BigDecimal getSalary() {
        return salary;
    }

    public void setSalary(BigDecimal salary) {
        this.salary = salary;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public LocalDateTime getCreatedAt() {
        return createdAt;
    }

    public void setCreatedAt(LocalDateTime createdAt) {
        this.createdAt = createdAt;
    }

    public Integer getIsActive() {
        return isActive;
    }

    public void setIsActive(Integer isActive) {
        this.isActive = isActive;
    }
}

Workflow

Extract table info: Get table name, column definitions, constraints, comment
Apply type mappings: See type_mappings.md for reference
Generate class name: Convert snake_case table name to PascalCase
Generate field names: Convert snake_case columns to camelCase
Add annotations: Generate @TableName, @TableId, @TableField based on column attributes
Generate getters/setters: Create standard getter and setter methods
Add imports: Include necessary imports for types and annotations

Package Structure

Entity classes should be placed in a package specified by the user. Common conventions:

Generic project: com.{company}.{module}.entity or com.{company}.{module}.model

Class Comment

Use table comment as class comment: