android SQLite数据库封装

终于有时间好好看看数据库了

今天下午自己封装了一个SQLite数据库

留着以后自己用吧

虽然还有许多要修改的地方

贴出代码先

package com.example.testdatabase;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DatabaseManager {

private DatabaseHelper dbHelper;
private static final String tableName = "name_table";

public DatabaseManager(Context context){

dbHelper = new DatabaseHelper(context);
}

public SQLiteDatabase getReadDatabase(){

return dbHelper.getReadableDatabase();
}

public void addData(String name, String num){
SQLiteDatabase db = dbHelper.getWritableDatabase();

ContentValues cv = new ContentValues();
cv.put("name", name);
cv.put("num", num);

try{
db.insertOrThrow(tableName, null, cv);
db.close();
}catch(Exception e){
e.printStackTrace();
}

}

public void deleteData(String strName){

String sql = "delete from " + tableName + " where name = '"+ strName +"'" ;
SQLiteDatabase db = dbHelper.getWritableDatabase();

try{
db.execSQL(sql);
//db.delete(tableName, "name ='" + strName + "' ", null);
}catch(Exception e){
e.printStackTrace();
}
}

//查找指定数据
public Cursor findData(String strNum){

String sql = "select * from " + tableName + " where num = " + strNum;
SQLiteDatabase db = dbHelper.getReadableDatabase();
Cursor cursor = null;

cursor = db.rawQuery(sql, new String[]{});

return cursor;
}

//删除表
public void deleteTable(){

String sql = "drop table " + tableName;
SQLiteDatabase db = dbHelper.getWritableDatabase();

try{
db.execSQL(sql);
}catch(Exception e){
e.printStackTrace();
}
}

public Cursor viewData(){

SQLiteDatabase db = dbHelper.getReadableDatabase();
String sql = "select * from " + tableName;
Cursor cursor = null;

try{
cursor = db.rawQuery(sql, new String[]{});
}catch(Exception e){
e.printStackTrace();
}
return cursor;
}

private class DatabaseHelper extends SQLiteOpenHelper{

private static final String dbNameString = "database.db";
private static final int db_version = 1;
private static final String nameTableString = "create table " + tableName + "(" + "name VARCHAR(20)," + "num VARCHAR(20)" + ");";

public DatabaseHelper(Context context) {
super(context, dbNameString, null, db_version);

}

public void onCreate(SQLiteDatabase db) {
db.execSQL(nameTableString);

}

@Override
public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {

}

}
}

//在外部类中调用如下
//如添加数据
DatabaseManager dm = null;
dm = new DatabaseManager(context);
dm.addData("张三", "123456");

本文出自 “爬过山见过海” 博客，转载请与作者联系！

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