android 本地数据库sqlite的封装

时间:2022-07-14 21:24:03

单机android   sqlite数据库的实现,这个数据库可与程序一起生成在安装包中

一、下载sqlite3.exe文件

二、运行 cmd 转到sqlite3.exe 所在目录  运行 sqlite3.exe 数据库名.db

    然后会出现sqlite>的命令提示符

输入创建表的语句, create table 表名(‘列’,‘列’。。。);(注意: 要在结束部分加  分号 )

    此时会在sqlite3.exe 所在目录,出现所建数据库的文件

三、如果想在Android中运行的话,需要在数据库中增添

 CREATE TABLE "android_metadata" ("locale" TEXT DEFAULT 'zh_CN')
INSERT INTO "android_metadata" VALUES ('zh_CN')

四、将数据库 复制到 Android项目中res/raw中

五、下面是代码:
public class TestSqlDatabase{

	private static final String DATABASE_PATH = "/data/data/your.package.name/databases";     //此处不要改动,这个为数据库在手机上的物理地址
private static final int DATABASE_VERSION = 0;
private static final String DATABASE_NAME = "test.db"; //此处为数据库名称 private static String outFileName = DATABASE_PATH + "/" + DATABASE_NAME; private Context context;
     private SQLiteDatabase database; public TestSqlDatabase(Context context) {
this.context = context; File file = new File(outFileName);
if (file.exists()) {
database = SQLiteDatabase.openOrCreateDatabase(outFileName, null);
if (database.getVersion() != DATABASE_VERSION) {
database.close();
file.delete();
}
}
try {
buildDatabase();
} catch (Exception e) {
e.printStackTrace();
} }
private void buildDatabase() throws Exception{
InputStream myInput = context.getResources().openRawResource(R.raw.test);
File file = new File(outFileName); File dir = new File(DATABASE_PATH);
if (!dir.exists()) {
if (!dir.mkdir()) {
throw new Exception("创建失败");
}
} if (!file.exists()) {
try {
OutputStream myOutput = new FileOutputStream(outFileName); byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
myOutput.close();
myInput.close();
} catch (Exception e) {
e.printStackTrace();
} }
} /**
* 查找
* @return
*/
public Cursor select() {
database = SQLiteDatabase.openOrCreateDatabase(outFileName, null);
String sql = "select * from note_table"; Cursor cursor = database.rawQuery(sql, null);
return cursor;
}
/**
* 插入
* @param word
* @param note
* @return
*/
public long insert(String word, String note) {
database = SQLiteDatabase.openOrCreateDatabase(outFileName, null);
ContentValues cv = new ContentValues();
cv.put("word", word);
cv.put("note", note); long result = database.insert("note_table", null, cv);
return result;
} /**
* 更新
* @param word
* @param note
* @return
*/
private int update(String word, String note) { //参数 word 为修改条件 note为修改内容
database = SQLiteDatabase.openOrCreateDatabase(outFileName, null); ContentValues cv = new ContentValues();
cv.put("note", note); int result = database.update("note_table", cv, "word=?", new String[]{word}); return result;
} /**
* 删除
* @param word
*/
public int deleteNote(String word) {
database = SQLiteDatabase.openOrCreateDatabase(outFileName, null);
int result = database.delete("note_table", "word=?", new String[]{word});
return result;
} public void close() {
database.close();
} }