package me.vamei.vamei.model; import java.util.LinkedList; import java.util.List; import android.content.ContentValues...; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase...db = this.getWritableDatabase(); db.delete(TABLE_CONTACTS, KEY_ID + " = ?"...db = this.getWritableDatabase(); Cursor cursor = db.rawQuery(query, null); // iterate...db = this.getWritableDatabase(); db.delete(TABLE_CATEGORIES, KEY_ID + " = ?"
import android.content.ContentValues; import android.content.Context; import android.database.Cursor;...import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; public...long insert(String text) { SQLiteDatabase db = this.getWritableDatabase(); ContentValues cv = new...row; } public void delete(int id) { SQLiteDatabase db = this.getWritableDatabase(); String where...public void update(int id, String text) { SQLiteDatabase db = this.getWritableDatabase(); String
; 5 import android.database.Cursor; 6 import android.database.sqlite.SQLiteDatabase; 7 8 public ...(db); 32 } 33 34 public Cursor select() { 35 SQLiteDatabase db = this.getReadableDatabase... db = this.getWritableDatabase(); 44 ContentValues cv = new ContentValues(); 45 cv.put...} 49 50 public void delete(int id){ 51 SQLiteDatabase db = this.getWritableDatabase(); 52...db = this.getWritableDatabase(); 60 String where = FIELD_ID + "= ?"
第二步:创建一个新的类BooksDB.java 这个类要继承于android.database.sqlite.SQLiteOpenHelper抽象类,我们要实现其中两个方法:onCreate(),onUpdate...; db.execSQL(sql); onCreate(db); } public Cursor select() { SQLiteDatabase db = this.getReadableDatabase...public long insert(String bookname,String author) { SQLiteDatabase db = this.getWritableDatabase();...(TABLE\_NAME, null, cv); return row; } //删除操作 public void delete(int id) { SQLiteDatabase db = this.getWritableDatabase...public void update(int id, String bookname,String author) { SQLiteDatabase db = this.getWritableDatabase
image.png 第二步:创建一个新的类BooksDB.java 这个类要继承于android.database.sqlite.SQLiteOpenHelper抽象类,我们要实现其中两个方法:onCreate...; db.execSQL(sql); onCreate(db); } public Cursor select() { SQLiteDatabase db = this.getReadableDatabase...public long insert(String bookname,String author) { SQLiteDatabase db = this.getWritableDatabase();...(TABLE\_NAME, null, cv); return row; } //删除操作 public void delete(int id) { SQLiteDatabase db = this.getWritableDatabase...public void update(int id, String bookname,String author) { SQLiteDatabase db = this.getWritableDatabase
onCreate(db); } public Cursor select() { SQLiteDatabase db = this.getReadableDatabase(); Cursor...long insert(String text) { SQLiteDatabase db = this.getWritableDatabase(); ContentValues cv = new...row; } public void delete(int id) { SQLiteDatabase db = this.getWritableDatabase(); String where...public void update(int id, String text) { SQLiteDatabase db = this.getWritableDatabase(); String...此项构造函数不提倡的,因为它会导致应用程序的UI线程正在执行游标的查询,从而可能会导致反应不佳,甚至应用程序无响应的错误。
db, int oldVersion, int newVersion) { 27 // TODO Auto-generated method stub 28 29 } 30...//关闭数据库 31 public void close() 32 { 33 this.getWritableDatabase().close(); 34 } 35...android.content.Intent; 6 import android.database.Cursor; 7 import android.database.sqlite.SQLiteDatabase...} 58 else 59 { 60 Toast.makeText(this, "用户名或者密码错误...) 构造方法,一般是传递一个要创建的数据库名称那么参数 onCreate(SQLiteDatabase db) 创建数据库时调用 onUpgrade(SQLiteDatabase db,int oldVersion
数据库已存在"); } //调用此方法时,判断数据库是否存在,不存在则创建 调用OnCreate方法,存在则不调,直接放回数据库对象 sqlitedb = this.getWritableDatabase...void createTable(SQLiteDatabase db){ db.execSQL("CREATE TABLE my_clock (" +...db = dbOpenHelper.getWritableDatabase(); db.delete("my_clock", "id=?"...> android="http://schemas.android.com/apk/res/android" android:layout_width="...db = null; Cursor cursor = null; try { db = dbHelper.getReadableDatabase
savedInstanceState) viewModel = ViewModelProvider(requireActivity()).get(NewsViewModel::class.java...savedInstanceState) viewModel = ViewModelProvider(requireActivity()).get(NewsViewModel::class.java...(CREATE_TABLE_MESSAGES); } @Override public void onUpgrade(SQLiteDatabase db, int oldVersion...} public void addMessage(Message message) { SQLiteDatabase db = this.getWritableDatabase...db = this.getWritableDatabase(); Cursor cursor = db.rawQuery(selectQuery, null); if (cursor.moveToFirst
// TODO Auto-generated constructor stub 7 } 8 9 @Override 10 public void onCreate(SQLiteDatabase...db) { 11 // TODO Auto-generated method stub 12 db.execSQL("CREATE TABLE IF NOT EXISTS...cv=new ContentValues(); 25 cv.put("name", name); 26 cv.put("age", age); 27 this.getWritableDatabase...{ 32 return false; 33 } 34 } 35 @Override 36 public void onUpgrade(SQLiteDatabase...db, int oldVersion, int newVersion) { 37 // TODO Auto-generated method stub 38 39 } sqlhelper
学习目标: 学习Android对SQL的支持。 理解在Java中使用SQL——通过SQLiteDatabase类。 创建数据库——SQLiteOpenHelper类。...Java中执行SQL:SQLiteDatabase类 为了在java代码中针对SQLite数据库执行一些SQL查询等操作,Android 框架提供了SQLiteDatabase类。...这个策略虽然简单,还是需要注意: 如果代码忘了显式关闭db实例,那么GC仅仅是回收此对象,这样会产生一个错误信息: 09-02 15:27:10.286: E/SQLiteDatabase(16433).../test.db' 09-02 15:27:10.286: E/SQLiteDatabase(16433): android.database.sqlite....(SQLiteDatabase.java:1943) 09-02 15:27:10.286: E/SQLiteDatabase(16433): at android.database.sqlite
DBManager.java: package com.example.test; import java.io.ByteArrayOutputStream; import java.io.IOException...; import java.io.InputStream; import android.content.Context; import android.database.sqlite.SQLiteDatabase...onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { // TODO Auto-generated method stub...2>缺失的脚本会直接跳过 private void initDb(SQLiteDatabase db, int oldVersion, int newVersion) { for (int i =...(); // TODO You may want to parse out comments here if (sqlStatement.length() > 0) { // 捕获错误
; import java.util.List; import java.util.Map; import android.app.Activity; import android.os.Bundle...package com.qingguow.mobilesafe.db.ado; import java.util.ArrayList; import java.util.HashMap; import...java.util.List; import java.util.Map; import android.content.ContentValues; import android.content.Context...; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import com.qingguow.mobilesafe.db.BlackNumberDBOpenHelper...; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteDatabase.CursorFactory
at com.xtc.bigdata.report.db.ReportDao.insert(ReportDao.java:46)...at android.content.ContentProvider$Transport.insert(ContentProvider.java:264)...at android.os.Binder.execTransact(Binder.java:565) 如上异常堆栈中的错误信息error code 5: database is locked,经过查找发现...") .getAbsolutePath(); SQLiteDatabase db = SQLiteDatabase.openDatabase(dbPath,...null, SQLiteDatabase.OPEN_READWRITE); Cursor cursor = db.query("Book", null, null,
import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper...; import java.util.List; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase...; import java.util.ArrayList; import java.util.List; import android.content.ContentValues; import...android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase...; import android.database.sqlite.SQLiteDatabase; import android.test.AndroidTestCase; import android.util.Log
package com.amaker.ch10.app; import java.util.HashMap; import android.content.ContentProvider...; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteQueryBuilder...break; default: throw new IllegalArgumentException("Uri错误...selectionArgs); break; default: throw new IllegalArgumentException("错误的...package com.amaker.ch10.app; import android.content.Context; import android.database.sqlite.SQLiteDatabase
; import android.widget.ListView; import android.widget.TextView; import db.Ranking; import db.User...接下来我贴出数据库代码和User类 User.java package db; public class User { private String userName; private...package db; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper...} Ranking.java package db; import java.util.ArrayList; import android.content.Context; import android.database.Cursor...; private SQLiteDatabase db; public Ranking(Context context) { helper = new DBOpenHelper
schemaVersion 1//数据库版本号 daoPackage 'com.aa'//设置DaoMaster、DaoSession、Dao包名 targetGenDir 'src/main/java..., 5) 错误: 方法不会覆盖或实现超类型的方法 Error:Execution failed for task ':app:compileDebugJavaWithJavac'...; import android.content.Context; import android.database.sqlite.SQLiteDatabase; import com.bestgo.callshow.bean.BlackInfoCallMIssedBean...; import java.util.List; /** * 作者:jiuqunZhang on 2018/4/28 21:12 * 邮箱:woshizhangjiqun@gmail.com...db = openHelper.getReadableDatabase(); return db; } private SQLiteDatabase getWritableDatabase
; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream...; import java.io.OutputStream; import android.content.Context; import android.database.sqlite.SQLiteDatabase...; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.database.sqlite.SQLiteException...= new DBHelper(this); * dbHelper.createDataBase(); * SQLiteDatabase db = dbHelper.getWritableDatabase...SQLiteDatabase.openOrCreateDatabase(dbf, null); // 复制asseets中的db文件到DB_PATH下
综合来看,即轻量 兼容 多端 无需配置 无外部依赖 拥有简单易懂的API 安全 在Android中如何使用 Android 提供的 SQLiteOpenHelper.java 是一个抽象类。...那么在Eclipse中创建Class类时,选择此抽象类模板即可,而在Android Studio中,必须自己写一个类来继承它,根据平时类名称简洁易懂的习惯上,我们创建的都是MyDataBaseHelper.java...或DataBaseHelper.java简写DBHelper.java。...数据库如何创建 Android Studio中 右键需要创建数据库.java文件的包,选择new,选择新建Class [QQ截图20201031100459] 在弹出框中选择输入类名称 [QQ...= new DBHelper(MainActivity.this, "info.db",null,1); //通过SQLiteDatabase指定数据库读写权限 SQLiteDatabase db