MySQL server version for the right syntax to use near '' at
MySQL server version for the right syntax to use near '' at line 1 问题描述: 线上日志在执行数据库表insert操作时,出现如下异常: ### Error updating database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException:? You have an error
MySQL server version for the right syntax to use near '' at line 1问题描述:
线上日志在执行数据库表insert操作时,出现如下异常:
### Error updating database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException:?
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
问题原因分析:
一般数据库SQL 异常会将sql拼写错误的文本解析错误地点放在near"" 中间引号中,而恰恰这次near语句出现出错地点没有标示,但是可以确定一点就是这个错误一定是sql语句错误造成的。
原因查找:
原因分析唯一可以确定的就是这个sql 拼写一定是错误的,那么是一定要查看源码拼写是否正确。
代码如下:
public String batchSave(Map<string object> params) { Collection<creative> collection = (Collection<creative>)params.get("collection"); StringBuffer buffer = new StringBuffer("insert into sem_creative(id, platCreativeId, platPlanId, platAdgroupId, planId, adgroupId, " + "title, desc1, desc2, pcDestinationUrl, pcDisplayUrl, mobileDestinationUrl, mobileDisplayUrl," + "pause, status, valid, accountId, platform, opstatus, creator, createTime) values"); for(Creative c : collection) { buffer.append("(").append(c.getId()).append(",") .append(StringUtil.emptyToNULL(c.getPlatCreativeId())).append(",") .append(StringUtil.emptyToNULL(c.getPlatPlanId())).append(",") .append(StringUtil.emptyToNULL(c.getPlatAdgroupId())).append(",") .append(c.getPlanId()).append(",") .append(c.getAdgroupId()).append(",") .append(StringUtil.emptyToNULL(c.getTitle())).append(",") .append(StringUtil.emptyToNULL(c.getDesc1())).append(",") .append(StringUtil.emptyToNULL(c.getDesc2())).append(",") .append(StringUtil.emptyToNULL(c.getPcDestinationUrl())).append(",") .append(StringUtil.emptyToNULL(c.getPcDisplayUrl())).append(",") .append(StringUtil.emptyToNULL(c.getMobileDestinationUrl())).append(",") .append(StringUtil.emptyToNULL(c.getMobileDisplayUrl())).append(",") .append(c.getPause()).append(",") .append(c.getStatus()).append(",") .append(c.getValid()).append(",") .append(c.getAccountId()).append(",") .append(c.getPlatform()).append(",") .append(c.getOpstatus()).append(",") .append(StringUtil.emptyToNULL(c.getCreator())).append(",") .append(StringUtil.emptyToNULL(c.getCreateTime().toString())).append("),"); } buffer.deleteCharAt(buffer.length()-1); return buffer.toString(); }</creative></creative></string>
?这里可以看到SQL语句,拼写是正确的,其中每个value值,对于空值的处理也正确。那为什么会报错呢?
等等,一定有哪里出错了!
for(Creative c : collection) {
?再看看这行代码,如果这个的集合类为空,会怎么样呢?这个一下错误就找到了,在collection为空的情况下,返回的SQL语句就只有前半句,执行就会报上述所描述错误。
问题追踪:
这个地方在一般情况下没有报错,也很少出现;那么为什么这次会出现呢?
这个地方还是得从源码入手
public final void syncUpload(String filePath, int segment) throws Exception{ if(segment > MAX_SEGMENT) { throw new IllegalArgumentException("分段上传数据量过大!"); } if(segment csvFileReader = getCSVReader(filePath); Iterator<e> it = csvFileReader.iterator(); List segmentList = new ArrayList(); while(true) { try { while(it.hasNext()) { if(segmentList.size() == this.segment) { try { syncBatchSave(segmentList); }catch(Exception e) { logger.error("批量添加异常: ", e); } segmentList = new ArrayList(); } E e = it.next(); segmentList.add(parse(e)); } }catch(Exception e) { logger.error("CSV文件解析异常: ", e); continue; } break; } syncBatchSave(segmentList); }</e>
?这里传入的segmentList看不会为空,但是parse(e)抛出异常时,则会在插入传入的集合不为null,但是集合的 size为0,所以在如上拼写SQL语句时,就会出现更新异常。
总结:
1.在接口的传入参数,一定要做边界校验,比如判空或者最大最小判断(如果集合大小超过20W也会出现异常);
2.团队代码规范中,要整理出代码规范要点,并每周定时review,对于不符合基本要求规范的惩罚5元团队建设基金;
1 楼 Engberber 22 小时前 今日决定将以前遇到的问题以及处理方式做一个分享
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