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Android?? SQLite???????

SQLite ? Android ????????????????? ????????????????????????????????????? API ??????? SQLite ???????????????????????????

1. ??????

SQLite ??? insert() ???????????????????????

• ???TableName?????????????
• ??????NullConstraints?????? null??????????????
• ????ContentValues?????????????

???????????????

Button addData = (Button) findViewById(R.id.add_data);
addData.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        SQLiteDatabase db = databaseHelper.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put("name", "?????");
        contentValues.put("author", "guolin");
        contentValues.put("pages", "452");
        contentValues.put("price", "35");
        
        db.insert("Book", null, contentValues);
        contentValues.clear();
        
        contentValues.put("name", "?????");
        contentValues.put("author", "guolin0");
        contentValues.put("pages", "4520");
        contentValues.put("price", "75");
        
        db.insert("Book", null, contentValues);
        contentValues.clear();
    }
});

2. ??????

update() ????????????????????????

• ????????????
• ?????????????????
• ?????WhereClause?????????????????????????

?????????????

Button updateData = findViewById(R.id.update_data);
updateData.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        SQLiteDatabase db = databaseHelper.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put("price", "88");
        
        db.update("Book", contentValues, "name=?", new String[]{"android development"});
    }
});

3. ??????

delete() ????????????????????????

• ????????????
• ????????????????????????????

?????????????

Button deleteData = findViewById(R.id.delete_data);
deleteData.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        SQLiteDatabase db = databaseHelper.getWritableDatabase();
        db.delete("Book", "pages < ?", new String[]{"500"});
    }
});

4. ??????

query() ????????????????????????

• ????????????
• ???????????????
• ????????????
• Group by????????
• Having?????????????
• ??????????

?????????????

Button queryData = (Button) findViewById(R.id.query_data);
queryData.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        SQLiteDatabase db = databaseHelper.getWritableDatabase();
        Cursor cursor = db.query("Book", null, null, null, null, null, null);
        
        if (cursor.moveToNext()) {
            do {
                String name = cursor.getString(cursor.getColumnIndex("name"));
                String author = cursor.getString(cursor.getColumnIndex("author"));
                int pages = cursor.getInt(cursor.getColumnIndex("pages"));
                double price = cursor.getDouble(cursor.getColumnIndex("price"));
                
                Log.d("MainActivity", "??: " + name);
                Log.d("MainActivity", "??: " + author);
                Log.d("MainActivity", "??: " + pages);
                Log.d("MainActivity", "??: " + price);
            } while (cursor.moveToNext());
        }
        cursor.close();
    }
});

???????????????????? SQLite ?????????????????????????? Android ????????????????????????????????