android中sqlite中判断表或视图是否存在

最新推荐文章于 2024-04-16 06:40:13 发布

原创最新推荐文章于 2024-04-16 06:40:13 发布 · 643 阅读

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本文提供了一种方法来检查SQLite数据库中特定的表或视图是否存在。通过构造SQL查询语句并使用SQLite的API来执行这些查询，可以确定表或视图的存在状态。

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   /**
   * 判断某张表是否存在
   *
   * @param tabName
   *            表名
   * @return
   */
   public boolean IsExistTable(String TableName) {
       boolean result = false;
       if (TableName == null) {
           return false;
       }
       SQLiteDatabase db = null;
       Cursor cursor = null;
       try {
           db = this.getReadableDatabase();

           String sql = "select count(*) as c from Sqlite_master where type ='table' and name ='"
                   + TableName.trim() + "' ";

           cursor = db.rawQuery(sql, null);

           if (cursor.moveToNext()) {

               int count = cursor.getInt(0);

               if (count > 0) {
                   result = true;
               }
           }

       } catch (Exception e) {

       }finally{
           closeCursor(cursor);
           db.close();
       }

       //System.out.println("表是否存在---"+result);
       return result;
   }

   /**
   * 判断视图是否已存在
   * @param viewName 视图的名字
   * @return
   * @author JL
   * @create 2011-5-20
   */
   public boolean IsExistView(String viewName) {
       boolean result = false;
       if (viewName == null) {
           return false;
       }
       SQLiteDatabase db = null;
       Cursor cursor = null;
       try {
           db = this.getReadableDatabase();

           String sql = "select count(*) as c from Sqlite_master where type ='view' and name ='"
                   + viewName.trim() + "' ";

           cursor = db.rawQuery(sql, null);

           if (cursor.moveToNext()) {

               int count = cursor.getInt(0);

               if (count > 0) {
                   result = true;
               }
           }

       } catch (Exception e) {
           e.printStackTrace();
       }finally{
           closeCursor(cursor);
           db.close();
       }
       return result;
   }