group12/doc/初融岐精读/NotesDatabaseHelper.java

import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import net.micode.notes.data.Notes.DataColumns;
import net.micode.notes.data.Notes.DataConstants;
import net.micode.notes.data.Notes.NoteColumns;

// 定义 NotesDatabaseHelper 类，继承自 SQLiteOpenHelper
public class NotesDatabaseHelper extends SQLiteOpenHelper {
    private static final String DB_NAME = "notes.db";
    private static final int DB_VERSION = 1;

    // 定义表名常量
    public interface TABLE {
        String NOTE = "note";
        String DATA = "data";
    }

    // 创建便签表的 SQL 语句
    private static final String CREATE_NOTE_TABLE_SQL =
            "CREATE TABLE " + TABLE.NOTE + "(" +
                    NoteColumns.ID + " INTEGER PRIMARY KEY," +
                    NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," +
                    NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," +
                    NoteColumns.TYPE + " INTEGER NOT NULL," +
                    NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" +
                    ")";

    // 创建数据索引的 SQL 语句
    private static final String CREATE_DATA_NOTE_ID_INDEX_SQL =
            "CREATE INDEX IF NOT EXISTS note_id_index ON " +
                    TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";

    // 定义触发器 SQL 语句
    private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER =
            "CREATE TRIGGER increase_folder_count_on_update " +
                    " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE +
                    " BEGIN " +
                    "  UPDATE " + TABLE.NOTE +
                    "   SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" +
                    "  WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" +
                    " END";

    // 其他触发器 SQL 语句省略，可根据实际情况补充

    // 构造函数
    public NotesDatabaseHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
    }

    // 创建便签表
    public void createNoteTable(SQLiteDatabase db) {
        db.execSQL(CREATE_NOTE_TABLE_SQL);
        reCreateNoteTableTriggers(db);
        createSystemFolder(db);
        Log.d("NotesDatabaseHelper", "note table has been created");
    }

    // 重新创建便签表的触发器
    private void reCreateNoteTableTriggers(SQLiteDatabase db) {
        db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update");
        // 其他触发器删除语句省略，可根据实际情况补充
        db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER);
        // 其他触发器创建语句省略，可根据实际情况补充
    }

    // 创建系统文件夹
    private void createSystemFolder(SQLiteDatabase db) {
        ContentValues values = new ContentValues();
        values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER);
        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
        db.insert(TABLE.NOTE, null, values);
        values.clear();
        values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER);
        values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM);
        db.insert(TABLE.NOTE, null, values);
    }

    // 创建数据表
    public void createDataTable(SQLiteDatabase db) {
        // 假设存在创建数据表的 SQL 语句
        String CREATE_DATA_TABLE_SQL = "CREATE TABLE " + TABLE.DATA + "(" +
                DataColumns.ID + " INTEGER PRIMARY KEY," +
                DataColumns.NOTE_ID + " INTEGER NOT NULL," +
                DataColumns.MIME_TYPE + " TEXT NOT NULL," +
                DataColumns.CONTENT + " TEXT," +
                DataColumns.DATA1 + " INTEGER," +
                DataColumns.DATA3 + " TEXT" +
                ")";
        db.execSQL(CREATE_DATA_TABLE_SQL);
        reCreateDataTableTriggers(db);
        db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL);
        Log.d("NotesDatabaseHelper", "data table has been created");
    }

    // 重新创建数据表的触发器
    private void reCreateDataTableTriggers(SQLiteDatabase db) {
        // 实现触发器的重新创建逻辑
    }

    // 数据库创建时调用
    @Override
    public void onCreate(SQLiteDatabase db) {
        createNoteTable(db);
        createDataTable(db);
    }

    // 数据库升级时调用
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // 实现数据库升级逻辑
    }
}