FMDB 版本迁移

痛定思痛。 2022-03-27 13:08 230阅读 0赞

## FMDB 版本迁移 ##

## 安装 ##

### 1. 通过`CocoaPods` ###

在项目根目录创建并编辑 Podfile 内容如下

$ cd /path/to/MyProject
    $ touch Podfile
    $ edit Podfile
    platform :ios, '5.0' 
    # Or platform :osx, '10.7'
    pod 'FMDBMigrationManager'

导入

$ pod install

打开项目，开始使用

$ open MyProject.xcworkspace

### 2. 手动 ###

添加 `FMDBMigrationManager.h` 和 `FMDBMigrationManager.m`，在使用的地方 `#import "FMDBMigrationManager.h"`

## 使用 ##

### 创建迁移表 ###

FMDBMigrationManager *manager = [FMDBMigrationManager managerWithDatabaseAtPath:@"path/to/your/DB.sqlite" migrationsBundle:[NSBundle mainBundle]];
    NSError *error = nil;
    BOOL success = [manager createMigrationsTable:&error];

### 创建补丁文件 ###

$ touch "`ruby -e "puts Time.now.strftime('%Y%m%d%H%M%S%3N').to_i"`"_CreateMyAwesomeTable.sql

在sql文件中写入数据库变更内容，然后添加到项目中 (Application Bundle)

### 迁移 ###

### 检查迁移状态 ###

FMDBMigrationManager *manager = [FMDBMigrationManager managerWithDatabaseAtPath:@"path/to/your/DB.sqlite" migrationsBundle:[NSBundle mainBundle]];
    NSLog(@"Has `schema_migrations` table?: %@", manager.hasMigrationsTable ? @"YES" : @"NO");
    NSLog(@"Origin Version: %llu", manager.originVersion);
    NSLog(@"Current version: %llu", manager.currentVersion);
    NSLog(@"All migrations: %@", manager.migrations);
    NSLog(@"Applied versions: %@", manager.appliedVersions);
    NSLog(@"Pending versions: %@", manager.pendingVersions);

## 使用记录 ##

《新天翼视讯项目》

1.  手动加入 FMDBMigrationManager 文件；
2.  生成、编辑sql补丁文件，并加入项目;
    
        ALTER TABLE DownLoadMedia ADD resumeData;
3.  添加迁移方法，不用指定脚本文件，会根据版本号自动识别;
    
        - (void)migrationDB {
        
            FMDBMigrationManager *manager = [FMDBMigrationManager managerWithDatabaseAtPath:kDATABASEFILE_PATH migrationsBundle:[NSBundle mainBundle]];
        
            NSError *error = nil;
            BOOL result = NO;
            if (!manager.hasMigrationsTable) {
                result = [manager createMigrationsTable:&error];
            }
        
            result = [manager migrateDatabaseToVersion:UINT64_MAX progress:nil error:&error];
        
            NSLog(@"Has `schema_migrations` table?: %@", manager.hasMigrationsTable ? @"YES" : @"NO");
            NSLog(@"Origin Version: %llu", manager.originVersion);
            NSLog(@"Current version: %llu", manager.currentVersion);
            NSLog(@"All migrations: %@", manager.migrations);
            NSLog(@"Applied versions: %@", manager.appliedVersions);
            NSLog(@"Pending versions: %@", manager.pendingVersions);
        }
4.  启动自动迁移;
    
        + (void)load {
            [[DataCenter sharedDataCenter] migrationDB];
        }

## 参考： ##

1.  [FMDB][]
2.  [FMDBMigrationManager][]
3.  [iOS SQLite 数据库迁移][iOS SQLite]

[FMDB]: https://github.com/ccgus/fmdb
[FMDBMigrationManager]: https://github.com/layerhq/FMDBMigrationManager
[iOS SQLite]: http://www.jianshu.com/p/c19dd08697bd