我做的方法根本不工作,列仍然存在.这是我的sql：

db.execsql("CREATE TEMPORARY TABLE Evaluation_backup(" + allColumnName + ");" 
                    + "INSERT INTO Evaluation_backup SELECT " + allColumnName + " FROM Evaluation;"
                    + "DROP TABLE Evaluation;" 
                    + "CREATE TABLE Evaluation("+ allColumnName + ");" 
                    + "INSERT INTO Evaluation SELECT " + allColumnName + " FROM Evaluation_backup;"
                    + "DROP TABLE Evaluation_backup;");

allColumnName是String包含除了要删除的列名称之外的所有列名. allColumnName内容如下：column1,column2,column3.

提前致谢.