#鸿蒙通关秘籍#如何在HarmonyOS中使用TaskPool进行频繁数据库操作？

在开发鸿蒙应用时，频繁的数据库操作可能会阻塞UI线程，因此可以通过ArkTS提供的TaskPool能力，将数据库操作任务移到子线程中。首先需要创建子任务，支持数据库的创建、插入、查询、清除等操作，然后在UI线程中调用这些子任务来完成数据库的操作。以下是主要步骤和代码实现：

1. 创建数据库及数据表： typescript @Concurrent async function create(context: Context) { const CONFIG: relationalStore.StoreConfig = { name: "Store.db", securityLevel: relationalStore.SecurityLevel.S1, }; let store: relationalStore.RdbStore = await relationalStore.getRdbStore(context, CONFIG); const CREATE_TABLE_SQL = "CREATE TABLE IF NOT EXISTS test (" + "id INTEGER PRIMARY KEY AUTOINCREMENT, " + "name TEXT NOT NULL, " + "age INTEGER, " + "salary REAL, " + "blobType BLOB)"; await store.executeSql(CREATE_TABLE_SQL); }

2. 插入数据： typescript @Concurrent async function insert(context: Context, valueBucketArray: Array<relationalStore.ValuesBucket>) { const CONFIG: relationalStore.StoreConfig = { name: "Store.db", securityLevel: relationalStore.SecurityLevel.S1, }; let store: relationalStore.RdbStore = await relationalStore.getRdbStore(context, CONFIG); await store.batchInsert("test", valueBucketArray as Object as Array<relationalStore.ValuesBucket>); }

3. 查询数据： typescript @Concurrent async function query(context: Context): Promise<Array<relationalStore.ValuesBucket>> { const CONFIG: relationalStore.StoreConfig = { name: "Store.db", securityLevel: relationalStore.SecurityLevel.S1, }; let store: relationalStore.RdbStore = await relationalStore.getRdbStore(context, CONFIG); let predicates: relationalStore.RdbPredicates = new relationalStore.RdbPredicates("test"); let resultSet = await store.query(predicates); // 查询所有数据 let result = new Array<relationalStore.ValuesBucket>(resultSet.rowCount) let index = 0; while (resultSet.goToNextRow()) { result[index++] = resultSet.getRow(); } resultSet.close(); return result; }

4. 清除数据库： typescript @Concurrent async function clear(context: Context) { const CONFIG: relationalStore.StoreConfig = { name: "Store.db", securityLevel: relationalStore.SecurityLevel.S1, }; await relationalStore.deleteRdbStore(context, CONFIG); }