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.

SQL to Java Entity

Quick Start

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

1. Parse the CREATE TABLE statement to extract table name, columns, and constraints
2. Map each MySQL column type to corresponding Java type
3. Convert snake_case column names to camelCase field names
4. Generate entity class with @TableName, @TableId, and JPA annotations
5. 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:

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

Class name conversion (PascalCase):

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

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

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

1. Extract table info: Get table name, column definitions, constraints, comment
2. Apply type mappings: See type_mappings.md for reference
3. Generate class name: Convert snake_case table name to PascalCase
4. Generate field names: Convert snake_case columns to camelCase
5. Add annotations: Generate @TableName, @TableId, @TableField based on column attributes
6. Generate getters/setters: Create standard getter and setter methods
7. 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:

/**
 * User Table
 */
@TableName("user_info")
public class UserInfo extends EntityBean {
}

Base Class

The entity may extend a framework base class if required:

• Framework: May extend BaseEntity, AbstractEntity, or no base class

Primary Key Strategy

MySQL Column Definition	IdType
AUTO_INCREMENT	IdType.AUTO
Manual assignment	IdType.INPUT
UUID	IdType.ASSIGN_UUID
Snowflake algorithm	IdType.ASSIGN_ID

Nullable Columns

For nullable columns (allows NULL), use wrapper types:

• Integer instead of int
• Long instead of long
• Boolean instead of boolean

Important Notes

1. Always use wrapper types (Integer, Long, Boolean) for nullable columns
2. Use BigDecimal for DECIMAL/NUMERIC types to maintain precision
3. Use LocalDateTime for DATETIME/TIMESTAMP types
4. Table name in @TableName should match the actual database table name exactly
5. The id field should use IdType.AUTO for auto-increment columns
6. Generate complete getter/setter methods for all fields
7. Follow framework conventions and package structure