FMDB 版本迁移

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

FMDBMigrationManager *manager = [FMDBMigrationManager managerWithDatabaseAtPath:@"path/to/your/DB.sqlite" migrationsBundle:[NSBundle mainBundle]];
NSError *error = nil;
BOOL success = [manager migrateDatabaseToVersion:UINT64_MAX progress:nil error:&error];

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