select count support

README.md

@@ -199,6 +199,8 @@ TuneDbParamPlugin#setJournalSizeLimit
 
 > 推荐开启自动升级，之后只需要修改版本号即可，无需手写 Migration
 
+> 自动升级默认不会生成删除列（drop column）的 sql，如需在自动升级时删除实体中已移除的列，配置 autoMigrateDropColumn: true 开启
+
 若仍想手动升级，可以通过配置 migration 进行升级
 
 ```
@@ -212,7 +214,8 @@ entities: [SampleEntity],
 migrations: [migration1_2, migration2_4],
 encrypt: false,
 securityLevel: relationalStore.SecurityLevel.S1,
-autoMigrate: false
+autoMigrate: false,
+autoMigrateDropColumn: false
 }).setLogger(new DBLog())
 .setEvent(new DBEventSender())
 .build()

build-profile.json5

@@ -5,6 +5,7 @@
       {
         "name": "default",
         "signingConfig": "default",
+        "targetSdkVersion": "6.1.1(24)",
         "compatibleSdkVersion": "5.0.1(13)",
         "runtimeOS": "HarmonyOS",
         "buildOption": {

rdbstore/README.md

@@ -202,6 +202,8 @@ TuneDbParamPlugin#setJournalSizeLimit
 
 > 推荐开启自动升级，之后只需要修改版本号即可，无需手写 Migration
 
+> 自动升级默认不会生成删除列（drop column）的 sql，如需在自动升级时删除实体中已移除的列，配置 autoMigrateDropColumn: true 开启
+
 通过配置 migration 进行升级
 
 ```
@@ -215,7 +217,8 @@ entities: [SampleEntity],
 migrations: [migration1_2, migration2_4],
 encrypt: false,
 securityLevel: relationalStore.SecurityLevel.S1,
-autoMigrate: false
+autoMigrate: false,
+autoMigrateDropColumn: false
 }).setLogger(new DBLog())
 .setEvent(new DBEventSender())
 .build()

rdbstore/src/main/ets/dao/RdbDao.ets

@@ -517,6 +517,20 @@ export class RdbDao<Entity extends object> {
     return indexes
   }
 
+  /**
+   * 根据谓词查询匹配的数据行数
+   */
+  public async count(predicates: relationalStore.RdbPredicates): Promise<number> {
+    const db = await this.database.getRdbImpl()
+    const result = await db.query(predicates, ['count(*)'], 'count', this.config.tableName)
+    let count = 0
+    if (result.goToNextRow()) {
+      count = result.getRow()['count(*)'] as number
+    }
+    result.close()
+    return count
+  }
+
   /**
    * 查询数据库中列数量
    */

rdbstore/src/main/ets/database/RdbConfig.ets

@@ -51,6 +51,10 @@ export interface RdbConfig {
    * @returns
    */
   autoMigrate: boolean
+  /**
+   * 自动升级时是否允许生成删除列（drop column）的 sql，默认关闭；开启后，实体中已移除的列会自动生成 DROP COLUMN 语句
+   */
+  autoMigrateDropColumn?: boolean
   /**
    * 从某个版本开始废弃低版本数据库，重新创建
    * 比如配置：5，会删除数据库版本为 1 2 3 4 这些版本数据库

rdbstore/src/main/ets/database/RdbOpenHelper.ets

@@ -64,7 +64,8 @@ export class RdbOpenHelper {
         const autoMigration = new Migration(rdbStore.version, this.database.config.version)
 
         // 计算且填充自动升级 migration
-        await DiffUtil.fillAutoUpgradeMigration(autoMigration, rdbStore)
+        await DiffUtil.fillAutoUpgradeMigration(autoMigration, rdbStore,
+          this.database.config.autoMigrateDropColumn ?? false)
 
         this.database.config.migrations.push(autoMigration)
       }

rdbstore/src/main/ets/database/auto/DiffUtil.ets

@@ -38,8 +38,10 @@ export namespace DiffUtil {
    * 列增加、列删除
    * @param migration
    * @param database
+   * @param allowDropColumn 是否允许生成删除列（drop column）的 sql，默认关闭
    */
-  export async function fillAutoUpgradeMigration(migration: Migration, database: relationalStore.RdbStore) {
+  export async function fillAutoUpgradeMigration(migration: Migration, database: relationalStore.RdbStore,
+    allowDropColumn: boolean = false) {
     const diffResult: Array<DiffResult<Object>> = new Array
     const newTables = Array.from(DbStructInfo.getInstance().tableMap.values())
     const newTableName = new Set(newTables.map((item) => item.tableName))
@@ -70,7 +72,7 @@ export namespace DiffUtil {
       const propDiff = calculateDiff(DiffType.COLUMN, props,
         DbStructInfo.getInstance().getPropsByName(table.tableName))
       diffResult.push(...propDiff)
-      fillColumnMigration(migration, table.tableName, propDiff)
+      fillColumnMigration(migration, table.tableName, propDiff, allowDropColumn)
     }
   }
 
@@ -132,15 +134,19 @@ export namespace DiffUtil {
 
   /**
    * 填充所有涉及列相关自动升级
+   * @param allowDropColumn 是否允许生成删除列（drop column）的 sql，默认关闭
    */
-  function fillColumnMigration(migration: Migration, tableName: string, result: Array<DiffResult<Property>>) {
+  function fillColumnMigration(migration: Migration, tableName: string, result: Array<DiffResult<Property>>,
+    allowDropColumn: boolean = false) {
     result.forEach(item => {
       switch (item.op) {
         case DiffOps.ADD:
           migration.addColumn(tableName, item.data.columnName, item.data.type)
           break;
         case DiffOps.DELETE:
-          migration.deleteColumn(tableName, item.data.columnName)
+          if (allowDropColumn) {
+            migration.deleteColumn(tableName, item.data.columnName)
+          }
           break;
       }
     })

rdbstore/src/main/ets/query/Query.ets

@@ -38,6 +38,15 @@ export class Query<Entity extends object> {
     return this.dao.queryPredicate(this.predicates, this._predicateDesc)
   }
 
+  /**
+   * 只获取匹配的数据行数，不获取内容
+   * @returns
+   */
+  count(): Promise<number> {
+    this.dao.database.extension.log?.d(this.tag, `query count: table: ${this.dao.config.tableName} do query predicates: ${this._predicateDesc}`)
+    return this.dao.count(this.predicates)
+  }
+
   /**
    * 谓词描述
    * @returns