建立sqlite資料庫

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;


public class DatabaseHelper extends SQLiteOpenHelper {

    //資料庫名字
    private static final String DB_NAME = "note.db";

    //本版號
    private static final int VERSION = 1;

    //建立表
    private static final  String CREATE_TABLE_NOTE = "CREATE TABLE note(_id integer primary key autoincrement,"+
            "title text, content text, createDate text, updateDate text)";

    //刪除表
    private static final String DROP_TABLE_NOTE = "drop table if exists note";


    public DatabaseHelper(Context context) {
        super(context, DB_NAME, null, VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        //SQLiteDatabase 用於操作資料庫的工具類
        db.execSQL(CREATE_TABLE_NOTE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL(DROP_TABLE_NOTE);
        db.execSQL(CREATE_TABLE_NOTE);
    }
}
 

import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import com.recker.note.data.MetaData;
import com.recker.note.data.Note;

import java.util.ArrayList;


public class DatabaseAdapter {

    private DatabaseHelper dbHelper;

    public DatabaseAdapter(Context context) {
        dbHelper = new DatabaseHelper(context);
    }

    /**
     * 新增資料
     *
     * @param note
     */
    public void create(Note note) {
        String sql = "insert into note(title, content, createDate, updateDate)values(?,?,?,?)";
        Object[] args = {note.getTitle(), note.getContent(), note.getCreateDate(), note.getUpdateDate()};
        SQLiteDatabase db = dbHelper.getWritableDatabase();

        db.execSQL(sql, args);
        db.close();
    }

    /**
     * 刪除資料
     *
     * @param id
     */
    public void remove(int id) {
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        String sql = "delete from note where _id = ?";
        Object[] args = {id};
        db.execSQL(sql, args);
        db.close();
    }

    /**
     * 修改資料
     *
     * @param note
     */
    public void update(Note note) {
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        String sql = "update note set title = ?, content = ?, updateDate = ? where _id = ?";
        Object[] args = {note.getTitle(), note.getContent(), note.getUpdateDate(), note.getId()};
        db.execSQL(sql, args);
        db.close();
    }

    /**
     * 按id查詢
     *
     * @param id
     * @return
     */
    public Note findById(int id) {
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String sql = "select * from note where _id = ?";
        Cursor cursor = db.rawQuery(sql, new String[]{String.valueOf(id)});

        Note note = null;
        if (cursor.moveToNext()) {
            note = new Note();

            note.setId(cursor.getInt(cursor.getColumnIndexOrThrow(MetaData.NoteTable._ID)));
            note.setTitle(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.TITLE)));
            note.setContent(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.CONTENT)));
            note.setCreateDate(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.CREATE_DATE)));
            note.setUpdateDate(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.UPDATE_DATE)));
        }
        cursor.close();
        db.close();

        return note;
    }

    /**
     * 查詢所有
     *
     * @return
     */
    public ArrayList<Note> findAll() {
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String sql = "select * from note";
        Cursor cursor = db.rawQuery(sql,null);


        ArrayList<Note> notes = new ArrayList<>();
        Note note = null;
        while (cursor.moveToNext()) {
            note = new Note();

            note.setId(cursor.getInt(cursor.getColumnIndexOrThrow(MetaData.NoteTable._ID)));
            note.setTitle(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.TITLE)));
            note.setContent(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.CONTENT)));
            note.setCreateDate(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.CREATE_DATE)));
            note.setUpdateDate(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.UPDATE_DATE)));
            notes.add(note);
        }
        cursor.close();
        db.close();
        return notes;
    }

    /**
     * 分頁查詢
     *
     * @param limit 預設查詢的數量
     * @param skip 跳過的行數
     * @return
     */
    public ArrayList<Note> findLimit(int limit, int skip) {
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String sql = "select * from note order by _id desc limit ? offset ?";
        String[] strs = new String[]{String.valueOf(limit), String.valueOf(skip)};
        Cursor cursor = db.rawQuery(sql,strs);


        ArrayList<Note> notes = new ArrayList<>();
        Note note = null;
        while (cursor.moveToNext()) {
            note = new Note();

            note.setId(cursor.getInt(cursor.getColumnIndexOrThrow(MetaData.NoteTable._ID)));
            note.setTitle(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.TITLE)));
            note.setContent(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.CONTENT)));
            note.setCreateDate(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.CREATE_DATE)));
            note.setUpdateDate(cursor.getString(cursor.getColumnIndexOrThrow(MetaData.NoteTable.UPDATE_DATE)));
            notes.add(note);
        }
        cursor.close();
        db.close();
        return notes;
    }
}