{"id":1213,"date":"2019-10-08T18:27:00","date_gmt":"2019-10-08T10:27:00","guid":{"rendered":"https:\/\/www.ray650128.com\/wordpress\/?p=1213"},"modified":"2022-02-26T13:09:43","modified_gmt":"2022-02-26T05:09:43","slug":"androidroom%e5%ad%b8%e7%bf%92%e7%ad%86%e8%a8%98","status":"publish","type":"post","link":"https:\/\/blog.ray650128.com\/?p=1213","title":{"rendered":"[Android]Room\u5b78\u7fd2\u7b46\u8a18"},"content":{"rendered":"\n<p>\u4ee5\u5f80\u6211\u5011\u5728\u4f7f\u7528 SQLite \u7684\u6642\u5019\uff0c\u5e38\u5e38\u9700\u8981\u5efa\u7acb SQLiteOpenHelper \u985e\u5225\u3002<\/p>\n\n\n\n<p>\u4e26\u900f\u904e SQL \u8a9e\u6cd5\u5be6\u4f5c\u4e00\u7cfb\u5217 CRUD \u65b9\u6cd5\u4f86\u5be6\u73fe\u300c\u65b0\u589e\u3001\u522a\u9664\u3001\u4fee\u6539\u3001\u67e5\u8a62\u300d\u7684\u529f\u80fd\u3002<\/p>\n\n\n\n<p>\u4f46\u9019\u6a23\u7684\u65b9\u5f0f\u592a\u904e\u7e41\u7463\uff0c\u70ba\u4e86\u89e3\u6c7a\u9019\u985e\u75db\u9ede\uff0c\u51fa\u73fe\u4e86\u4e0d\u5c11 ORM \u6846\u67b6\u3002<\/p>\n\n\n\n<p>Room \u662f Android Jetpack \u7684\u6210\u54e1\u4e4b\u4e00\uff0c\u76ee\u7684\u662f\u7528\u4f86\u5be6\u4f5c Java\/Kotlin \u548c SQLite \u9593\u7684\u8cc7\u6599\u8f49\u63db\u5c64\uff0c\u4e5f\u5c31\u662f ORM\u3002<\/p>\n\n\n\n<p>\u7531\u65bc\u5148\u524d\u76f4\u63a5\u4f7f\u7528 Realm \u4f86\u89e3\u6c7a\u9019\u4e9b\u554f\u984c\uff0c\u56e0\u6b64\u6c92\u6709\u4f7f\u7528\u904e\u5176\u4ed6\u7684\u6846\u67b6\u3002<\/p>\n\n\n\n<p>\u525b\u597d\u7531\u65bc\u516c\u53f8\u90e8\u9580\u7e2e\u6e1b\u88ab\u88c1\uff0c\u56e0\u6b64\u6709\u591a\u9918\u6642\u9593\u4f86\u5b78\u7fd2\u65b0\u6280\u8853\uff0c\u56e0\u6b64\u5c31\u6709\u4e86\u672c\u7bc7\u5b78\u7fd2\u7d00\u9304\u3002<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u4f7f\u7528 Room<\/h2>\n\n\n\n<h2 class=\"wp-block-heading\">\u5efa\u7acb\u5143\u4ef6<\/h2>\n\n\n\n<p>\u9996\u5148\u5148\u5728 app \u6a21\u7d44\u7684 build.gradle \u4e2d\u52a0\u5165\u4f9d\u8cf4\uff0c\u5982\u4e0b\u6240\u793a\uff1a\u63a5\u8457\u5be6\u4f5c Entity\u3001DAO\u3001Database\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"kotlin\" class=\"language-kotlin line-numbers\">dependencies {\n    def room_version = \"2.2.0-alpha02\"\n    implementation \"androidx.room:room-runtime:$room_version\"\n    kapt \"androidx.room:room-compiler:$room_version\"\n}<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Entity \u90e8\u5206<\/h2>\n\n\n\n<p>Entity\u5be6\u969b\u4e0a\u5c31\u662f\u8cc7\u6599\u5728\u7a0b\u5f0f\u78bc\u4e2d\u7684\u7269\u4ef6\u5c0d\u61c9\uff0cRoom\u6703\u900f\u904e\u9019\u500b\u985e\u5225\u5c07\u8cc7\u6599\u8f49\u63db\u6210\u7269\u4ef6\uff0c\u8b93\u6211\u5011\u53ef\u4ee5\u5728Java\/Kotlin\u4e0a\u4f7f\u7528\u3002\u7a0b\u5f0f\u78bc\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"kotlin\" class=\"language-kotlin line-numbers\">@Entity\ndata class Student(\n    @PrimaryKey(autoGenerate = true)\n    var id: Int? = 0,\n    var name: String = \"\",\n    var birthday: Long = 0L,\n    var studentGrade: Int = 0,\n    var studentClass: Int = 0\n)<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">DAO \u90e8\u5206<\/h2>\n\n\n\n<p>DAO\u9019\u500b\u4ecb\u9762\u4e3b\u8981\u662f\u8b93\u6211\u5011\u81ea\u5df1\u5b9a\u7fa9\u65b0\u522a\u6539\u67e5\u529f\u80fd\uff0c\u7a0b\u5f0f\u78bc\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"kotlin\" class=\"language-kotlin line-numbers\">@Dao\ninterface StudentDao {\n\n    @Insert(onConflict = OnConflictStrategy.REPLACE)\n    fun add(item: Student): Long\n\n    @Delete\n    fun deleteData(item: Student)\n\n    @Update\n    fun update(item: Student)\n\n    @Query(\"SELECT * FROM student WHERE name LIKE :name\")\n    fun findByName(name: String): Student\n\n    @Query(\"SELECT * FROM student\")\n    fun getAll(): List&lt;Student&gt;\n}<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Database \u90e8\u5206<\/h2>\n\n\n\n<p>\u9019\u500b\u90e8\u5206\u662f\u8cc7\u6599\u5eab\u771f\u6b63\u7684\u5be6\u9ad4\uff0c\u9019\u88e1\u5b9a\u7fa9\u4e86\u8cc7\u6599\u5eab\u7684\u6a94\u540d\u3001\u6240\u5305\u542b\u7684\u8cc7\u6599\u8868\u3001\u4ee5\u53ca\u8cc7\u6599\u5eab\u7248\u672c\u7b49\u53c3\u6578\u3002\u7a0b\u5f0f\u78bc\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"kotlin\" class=\"language-kotlin line-numbers\">@Database(entities = [(Student::class)], version = 1)\nabstract class MyDbHelper : RoomDatabase() {\n\n    companion object {\n        @Volatile\n        private var instance: MyDbHelper? = null\n        private val LOCK = Any()\n\n        operator fun invoke(context: Context) = instance ?: synchronized(LOCK) {\n            instance ?: buildDatabase(context).also { instance = it }\n        }\n\n        private fun buildDatabase(context: Context) = Room.databaseBuilder(\n            context,\n            MyDbHelper::class.java, \"students.db\"\n        ).allowMainThreadQueries().build()\n    }\n\n    abstract fun getRoomDao(): StudentDao\n}<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u5982\u4f55\u4f7f\u7528<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">1.\u5be6\u4f8b\u5316 Database \u7269\u4ef6<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"kotlin\" class=\"language-kotlin line-numbers\">db = MyDbHelper(this)<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2.\u65b0\u589e\u8cc7\u6599\u65b9\u5f0f<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"kotlin\" class=\"language-kotlin line-numbers\">val student = Student(\n    id = null,\n    name = \"\u738b\u5c0f\u660e\",\n    birthday = 1368633600000,\n    studentGrade = 6,\n    studentClass = 18\n)\n\ndb.getRoomDao().add(student)<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3.\u522a\u9664\u8cc7\u6599\u65b9\u5f0f<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"kotlin\" class=\"language-kotlin line-numbers\">db.getRoomDao().delete(student)<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">4.\u4fee\u6539\u8cc7\u6599\u65b9\u5f0f<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"kotlin\" class=\"language-kotlin line-numbers\">db.getRoomDao().update(student)<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">5.\u67e5\u8a62\u8cc7\u6599\u65b9\u5f0f<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"kotlin\" class=\"language-kotlin line-numbers\">val studentList: List&lt;Student> = db.getRoomDao().getAll()<\/code><\/pre>\n\n\n\n<p><\/p>\n\n\n\n<p>\u4ee5\u4e0a\u662f Room \u6846\u67b6\u7684\u5b78\u7fd2\u7d00\u9304\uff0c\u7167\u8457\u67e5\u5230\u7684\u8cc7\u6599\u4e00\u6b65\u4e00\u6b65\u5be6\u4f5c\u4e0b\u4f86\uff0c\u611f\u89ba\u9084\u883b\u5bb9\u6613\u4e0a\u624b\u7684\u3002\u82e5\u4e4b\u5f8c\u6709\u6a5f\u6703\u5c0e\u5165\u5230\u5c08\u6848\u4e2d\uff0c\u6703\u518d\u88dc\u5145\u5176\u4ed6\u4f7f\u7528\u5fc3\u5f97\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4ee5\u5f80\u6211\u5011\u5728\u4f7f\u7528 SQLite \u7684\u6642\u5019\uff0c\u5e38\u5e38\u9700\u8981\u5efa\u7acb SQLiteOpenHelper \u985e\u5225\u3002 \u4e26\u900f\u904e SQL  &hellip; <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-1213","post","type-post","status-publish","format-standard","hentry","category-2"],"_links":{"self":[{"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=\/wp\/v2\/posts\/1213","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1213"}],"version-history":[{"count":5,"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=\/wp\/v2\/posts\/1213\/revisions"}],"predecessor-version":[{"id":1220,"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=\/wp\/v2\/posts\/1213\/revisions\/1220"}],"wp:attachment":[{"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1213"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1213"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.ray650128.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1213"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}