使用Django来清理数据库中的数据

数据库中的数据清理

问题描述：在我所使用的系统中，由于历史和各种原因，导致数据库中表里面记录的数据，是有问题的，有重复的和不完整的数据

解决方案：首先，由于这些数据的量还是挺大的，手工的清理肯定不行，

然后，我就想写SQL脚本来按照约定的规则进行更新，可以利用游标

来完成表中的记录的遍历，但是SQL是面向结构化的查询语言，不是面向过程的，所以虽然可以但是没有C和python这样的面向过程的使用方便，

后来，我想直接在我的项目中新建一个方法，然后通过浏览器的地址栏来调用，就可以了。

PS：虽然说Django的orm很方便，但是自己使用起来还是非常的尴尬，一些筛选条件和语法规则，我还是得在网上查找例子才知道怎么用

幸好提供了直接执行SQL语句方法，我在清理的过程中，用的就是执行原生的SQL语句。

代码如下:

   def datetimestr():    return datetime.now().strftime('%Y%m%d-%H%M%S')+'>>>'   def update_dcData(req):        log_path='apps/dc/l10n_reports'    update_dcData_log=open(log_path+'updateDcdataLog.log','w+')    sql_getProjectIDs='select a.project_id from' \                       ' (select count(*) num,project_id from dc_data where lableName=%s group by project_id) a,' \                       ' (select count(*) num ,project_id from management_project_target_lang group by project_id) b' \                       ' where a.project_id=b.project_id and a.num!=b.num order by project_id'        sql_getAllProjectIDs='select project_id from management_project'        sql_getLanguageSections='select b.name from management_project_target_lang a,management_l10nlanguage b' \                            ' where a.project_id=%s and a.l10nlanguage_id=b.id and b.id!="1"'                                sql_getRecords='select id, languageSection,value from dc_data where lableName =%s and project_id=%s and important="1"'        sql_addRecordByID='insert into dc_data(lableName,languageSection,type,value,project_id,task_id,' \                'important,unit,settlement,workload) ' \                'select lableName,languageSection,type,value,project_id,task_id,important,unit,settlement,workload ' \                'from dc_data where id=%s'     sql_updateLgs='update dc_data set languageSection=%s where id=%s'        sql_getLableNames='select lableName from dc_data where lableName like "%%_all" group by lableName'        update_dcData_log.write(datetimestr()+'sql_getLableNames'+'>>>'+sql_getLableNames+'\n')    update_dcData_log.write(datetimestr()+'sql_getRecords'+'>>>'+sql_getRecords+'\n')    update_dcData_log.write(datetimestr()+'sql_getProjectIDs'+'>>>'+sql_getProjectIDs+'\n')    update_dcData_log.write(datetimestr()+'sql_getLanguageSections'+'>>>'+sql_getLanguageSections+'\n')        update_dcData_log.write(datetimestr()+'sql_addRecordByID'+'>>>'+sql_addRecordByID+'\n')        update_dcData_log.write(datetimestr()+'sql_updateLgs'+'>>>'+sql_updateLgs+'\n')        context=Context({'msg':'Success'})    resp=render_to_response("report/clean_data.html", context,                               context_instance=RequestContext(req))        cursor=connection.cursor()    try:        cursor.execute(sql_getLableNames)        lableNames=cursor.fetchall()    except Exception,e:        update_dcData_log.write(datetimestr()+'execute sql_getLableNames error '+str(e)+'\n')        context=Context({'msg':'Error'})        return render_to_response("report/clean_data.html", context,                               context_instance=RequestContext(req))     for lableName in lableNames:        try:            cursor.execute(sql_getProjectIDs,[lableName[0]])            projectIDs=cursor.fetchall()        except Exception,e:            update_dcData_log.write(datetimestr()+'execute sql_getProjectIDs error '+str(e)+'\n')            context=Context({'msg':'Error'})            return render_to_response("report/clean_data.html", context,                               context_instance=RequestContext(req))         for pid in projectIDs:            try:                cursor.execute(sql_getRecords,[lableName[0],str(pid[0])])                records=cursor.fetchall()                cursor.execute(sql_getLanguageSections,[str(pid[0])])                languageSections=cursor.fetchall()            except Exception,e:                update_dcData_log.write(datetimestr()+'execute sql_getRecords or sql_getLanguageSections error '+str(e)+'\n')                context=Context({'msg':'Error'})                return render_to_response("report/clean_data.html", context,                               context_instance=RequestContext(req))             values,lgs=[],[]            baseValue=str(records[0][2])            baseID=str(records[0][0])            for item in records:                lgs.append(str(item[1]))                values.append(str(item[2]))                if baseValue!=str(item[2]):                    baseValue='false'            targetLgs=[str(item[0]) for item in languageSections]            if len(lgs)<1 or len(targetLgs)<1:                baseValue=='false'            if 'all' not in lgs:                try:                    cursor.execute(sql_addRecordByID,[baseID])                    cursor.execute(sql_updateLgs,['all',baseID])                    transaction.commit_unless_managed()                except Exception,e:                    update_dcData_log.write(datetimestr()+'execute sql_addRecordByID or sql_updateLgs error (all)'+str(e)+'\n')                    context=Context({'msg':'Error'})                    return render_to_response("report/clean_data.html", context,                                   context_instance=RequestContext(req))                                             update_dcData_log.write(datetimestr()+"all record is add into dc_data,the lableName and projectID were "+str(lableName[0])+'-'+str(pid[0])+'\n')                        if baseValue=='false':                update_dcData_log.write(datetimestr()+"please update this record mutually,the lableName and projectID were "+str(lableName[0])+'-'+str(pid[0])+'\n')            else:                if len(lgs)>len(targetLgs):                    update_dcData_log.write(datetimestr()+"the lableName languageSection length is longer than target numbers lableName and projectID were "+str(lableName[0])+'-'+str(pid[0])+'\n')                else:                    for lg in targetLgs:                        if lg not in lgs:                            try:                                cursor.execute(sql_addRecordByID,[baseID])                                cursor.execute(sql_updateLgs,[lg,baseID])                                transaction.commit_unless_managed()                            except Exception,e:                                update_dcData_log.write(datetimestr()+'execute sql_addRecordByID or sql_updateLgs error (lg)'+str(e)+'\n')                                context=Context({'msg':'Error'})                                return render_to_response("report/clean_data.html", context,                                   context_instance=RequestContext(req))                                                             update_dcData_log.write(datetimestr()+lg+" record is add into dc_data,the lableName and projectID were "+str(lableName[0])+'-'+str(pid[0])+'\n')                                                update_dcData_log.close()                             return  resp