关于JDBC的批量操作executeBatch()所引发sql语句异常
java.sql.BatchUpdateException: 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 '('1512144017', 'quqiang01' at line 1
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createBatchUpdateException(SQLError.java:1162)
at com.mysql.jdbc.PreparedStatement.executeBatchedInserts(PreparedStatement.java:1587)
at com.mysql.jdbc.PreparedStatement.executeBatchInternal(PreparedStatement.java:1253)
at com.mysql.jdbc.StatementImpl.executeBatch(StatementImpl.java:970)
Caused by: 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 '('1512144017', 'quqiang01' at line 1
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:943)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3973)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3909)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2527)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2487)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1858)
at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2079)
at com.mysql.jdbc.PreparedStatement.executeUpdateInternal(PreparedStatement.java:2013)
at com.mysql.jdbc.PreparedStatement.executeLargeUpdate(PreparedStatement.java:5104)
at com.mysql.jdbc.PreparedStatement.executeBatchedInserts(PreparedStatement.java:1548)
... 5 more
最近在使用JDBC的时候,一个比较坑的细节,就是关于他里面使用PreparedStatement或者Statement 的 addBatch()/executeBatch()的具体实现问题;
不要手贱在你传入的sql语句没末尾加上分号;
具体是这样:
1 //以一个批量提交的实现工具举例 2 // List<List<Object>> lists: 所有数据的list 3 // List<Object>:单条数据"值"的list 4 5 public void batchExecutePstamt(String sql, List < List < Object >> lists) { 6 try { 7 connection.setAutoCommit(false); 8 pstmt = connection.prepareStatement(sql); 9 if (lists != null && !lists.isEmpty()) { 10 for (List < Object > cList: lists) { 11 if (cList == null || cList.isEmpty()) 12 continue; 13 14 for (int i = 0; i < cList.size(); i++) { 15 pstmt.setObject(i + 1, cList.get(i)); 16 } 17 pstmt.addBatch(); 18 } 19 log.info(pstmt.toString()); 20 pstmt.executeBatch(); 21 connection.commit(); 22 } 23 } catch (SQLException e) { 24 e.printStackTrace(); 25 } 26 }
在这里,我们传入大量的需要插入的对象的List<List<Object>>,里面的 List<Object> 就是某一条具体的记录的值;
如果你调用的时候, 在传入sql的时候, 传入了类似于 insert into `tablename` (name,age) values (?,?); 的sql语句
那么他每次addBatch的时候就会在
com.mysql.jdbc.PreparedStatement.addBatch()的创建com.mysql.jdbc.PreparedStatement.BatchParams 然后放进batchedArgs 静态列表里面
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 public void addBatch() throws SQLException { 2 synchronized (checkClosed().getConnectionMutex()) { 3 if (this.batchedArgs == null) { 4 this.batchedArgs = new ArrayList<Object>(); 5 } 6 7 for (int i = 0; i < this.parameterValues.length; i++) { 8 checkAllParametersSet(this.parameterValues[i], this.parameterStreams[i], i); 9 } 10 11 this.batchedArgs.add(new BatchParams(this.parameterValues, this.parameterStreams, this.isStream, this.streamLengths, this.isNull)); 12 } 13 }
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 public class BatchParams { 2 public boolean[] isNull = null; 3 4 public boolean[] isStream = null; 5 6 public InputStream[] parameterStreams = null; 7 8 public byte[][] parameterStrings = null; 9 10 public int[] streamLengths = null; 11 12 BatchParams(byte[][] strings, InputStream[] streams, boolean[] isStreamFlags, int[] lengths, boolean[] isNullFlags) { 13 // 14 // Make copies 15 // 16 this.parameterStrings = new byte[strings.length][]; 17 this.parameterStreams = new InputStream[streams.length]; 18 this.isStream = new boolean[isStreamFlags.length]; 19 this.streamLengths = new int[lengths.length]; 20 this.isNull = new boolean[isNullFlags.length]; 21 System.arraycopy(strings, 0, this.parameterStrings, 0, strings.length); 22 System.arraycopy(streams, 0, this.parameterStreams, 0, streams.length); 23 System.arraycopy(isStreamFlags, 0, this.isStream, 0, isStreamFlags.length); 24 System.arraycopy(lengths, 0, this.streamLengths, 0, lengths.length); 25 System.arraycopy(isNullFlags, 0, this.isNull, 0, isNullFlags.length); 26 } 27 } 28 29 PreparedStatement batchedStatement = null;
然后会在最后使用executeBatch()的时候处理 batchedArgs中的 数据
处理的步骤为:
>> com.mysql.jdbc.StatementImpl.executeBatch()
>> com.mysql.jdbc.PreparedStatement.executeBatchInternal()
这里回去判断你设置的一些参数, 比如connection.getRewriteBatchedStatements(), 这个有助于批量数据处理的参数, 需要在jdbc.url连接中设置 rewriteBatchedStatements = true, 不过好像只针对于某个版本(5.2 ?不确定 )以后的数据操作性能有帮助.
在这里会进入一个将多个PreparedStatement转化为 BLUK 模式的一条语句;(bluk模式不知道的请自行百度)
>> com.mysql.jdbc.PreparedStatement.executeBatchedInserts(int)
这里面有一段源码:
1 PreparedStatement batchedStatement = null; 2 3 int batchedParamIndex = 1; 4 long updateCountRunningTotal = 0; 5 int numberToExecuteAsMultiValue = 0; 6 int batchCounter = 0; 7 CancelTask timeoutTask = null; 8 SQLException sqlEx = null; 9 10 long[]updateCounts = new long[numBatchedArgs]; 11 //上面不多说 12 13 try { 14 //这句会把初始化我们传进来的sql 15 //我们传进来的是类似于 insert into tablename (columns…) values (?,?...)这种 16 //到这里相当于初始化成 INSERT INTO tablename` (`name`, `age`) values (** NOT SPECIFIED **, ** NOT SPECIFIED **); 17 //然后他会根据顺序传进我们上面所传进的多个已经赋值的PreparedStatement, 18 batchedStatement = /* FIXME -if we ever care about folks proxying our MySQLConnection */ 19 prepareBatchedInsertSQL(locallyScopedConn, numValuesPerBatch); 20 21 if (locallyScopedConn.getEnableQueryTimeouts() && batchTimeout != 0 && locallyScopedConn.versionMeetsMinimum(5, 0, 0)) { 22 timeoutTask = new CancelTask(batchedStatement); 23 locallyScopedConn.getCancelTimer().schedule(timeoutTask, batchTimeout); 24 } 25 26 if (numBatchedArgs < numValuesPerBatch) { 27 numberToExecuteAsMultiValue = numBatchedArgs; 28 } else { 29 numberToExecuteAsMultiValue = numBatchedArgs / numValuesPerBatch; 30 } 31 32 int numberArgsToExecute = numberToExecuteAsMultiValue * numValuesPerBatch; 33 34 for (int i = 0; i < numberArgsToExecute; i++) { 35 if (i != 0 && i % numValuesPerBatch == 0) { 36 try { 37 updateCountRunningTotal += batchedStatement.executeLargeUpdate(); 38 } catch (SQLException ex) { 39 sqlEx = handleExceptionForBatch(batchCounter - 1, numValuesPerBatch, updateCounts, ex); 40 } 41 42 getBatchedGeneratedKeys(batchedStatement); 43 batchedStatement.clearParameters(); 44 batchedParamIndex = 1; 45 46 } 47 //@see 这里是关键 48 //@see 如果还有后续的PreparedStatement,根据后面的一个参数,那么他就会将batchedStatement设置为: 49 // INSERT INTO tablename` (`name`, `age`) values("名字1",'23'), (** NOT SPECIFIED **, ** NOT SPECIFIED **); 50 51 //@see 问题就在这里 52 //@see 如果你传入的sql :" insert into tablename (columns…) values (?,?...);"是这样的,那么生成的单条语句以及单个PreparedStatement没有任何问题,你拿到数据库执行去也OK 53 //@see 但是他现在要给你转为BLUK模式的,如果你结尾带了分号,语句就会变成: 54 // INSERT INTO tablename` (`name`, `age`) values("名字1",'23');, (** NOT SPECIFIED **, ** NOT SPECIFIED **);然后等待下一次填充参数 55 //@see 多的这个分号就是导致sql语句错误的原因 56 57 58 //@see 有兴趣可以进源码的这个方法看看 59 batchedParamIndex = setOneBatchedParameterSet(batchedStatement, batchedParamIndex, this.batchedArgs.get(batchCounter++)); 60 } 61 62 try { 63 updateCountRunningTotal += batchedStatement.executeLargeUpdate(); 64 } catch (SQLException ex) { 65 sqlEx = handleExceptionForBatch(batchCounter - 1, numValuesPerBatch, updateCounts, ex); 66 } 67 68 getBatchedGeneratedKeys(batchedStatement); 69 70 numValuesPerBatch = numBatchedArgs - batchCounter; 71 } 72 finally { 73 if (batchedStatement != null) { 74 batchedStatement.close(); 75 batchedStatement = null; 76 } 77 }