Schema 差异检测

diffSchemas 对比当前数据库 Schema 与目标 Schema，检测表和列的增删改差异。generateMigrationSQL 根据差异生成 up / down 双向迁移 SQL。

基本用法

import { diffSchemas, generateMigrationSQL } from "@ventostack/database";

const current = [
  {
    name: "users",
    columns: [
      { name: "id", type: "bigint", primaryKey: true },
      { name: "name", type: "varchar", nullable: false },
    ],
  },
];

const target = [
  {
    name: "users",
    columns: [
      { name: "id", type: "bigint", primaryKey: true },
      { name: "name", type: "varchar", nullable: false },
      { name: "email", type: "varchar", nullable: true },
    ],
  },
  {
    name: "posts",
    columns: [
      { name: "id", type: "bigint", primaryKey: true },
      { name: "title", type: "varchar" },
    ],
  },
];

const diff = diffSchemas(current, target);
// diff.addedTables    → ["posts"]
// diff.modifiedTables → [{ table: "users", addedColumns: [...], ... }]

const { up, down } = generateMigrationSQL(diff);
// up:  正向迁移 SQL
// down: 回滚 SQL

差异结构

SchemaDiff

字段	类型	说明
addedTables	string[]	新增表名列表
removedTables	string[]	移除表名列表
modifiedTables	TableDiff[]	发生变更的表差异列表

TableDiff

字段	类型	说明
table	string	表名
addedColumns	ColumnSchema[]	新增列
removedColumns	string[]	移除的列名
modifiedColumns	ColumnDiff[]	变更的列差异

ColumnDiff

字段	类型	说明
column	string	列名
changes	string[]	变更项（type、nullable、default）
from / to	Partial<ColumnSchema>	变更前后的值

函数签名

函数	说明
diffSchemas(current, target)	对比两个 Schema，返回 SchemaDiff
generateMigrationSQL(diff)	生成 { up, down } 迁移 SQL 数组