# android.database.sqlite.SQLiteException：无法从游标读取：列 'price' 的类型为 REAL，但应为 INTEGER（代码 0 SQLITE_MISMATCH）

- **ID:** `android/room-cursor-mismatch-column-type`
- **领域:** android
- **类别:** data_error
- **错误码:** `SQLITE_MISMATCH`
- **验证级别:** ai_generated
- **修复率:** 82%

## 根因

Room 实体在 Kotlin/Java 中将列定义为整数类型（例如 Int 或 Long），但由于迁移失败或直接数据库操作，实际的 SQLite 列包含浮点值（REAL）。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| Room 2.5.0 | active | — | — |
| Room 2.6.0 | active | — | — |
| SQLite 3.32.2 | active | — | — |

## 解决方案

1. ```
   Create a manual migration in your RoomDatabase class that converts the column type. For example: `val MIGRATION_1_2 = object : Migration(1, 2) { override fun migrate(database: SupportSQLiteDatabase) { database.execSQL("ALTER TABLE products ADD COLUMN price_new INTEGER") database.execSQL("UPDATE products SET price_new = CAST(price AS INTEGER)") database.execSQL("ALTER TABLE products DROP COLUMN price") database.execSQL("ALTER TABLE products RENAME COLUMN price_new TO price") } }`
   ```
2. ```
   Use `@ColumnInfo(typeAffinity = ColumnInfo.REAL)` in your entity to match the actual column type, then handle the conversion in your app logic (e.g., `price.toInt()`).
   ```

## 无效尝试

- **** — This only works during development; in production, users lose all local data. The underlying schema mismatch returns when migration is reapplied. (70% 失败率)
- **** — Changing the entity type alone does not fix the existing data; Room still reads the column as REAL, and the migration must handle type conversion explicitly. (85% 失败率)