Duplicate entry ' 1 ' for key ' PRIMARY ' (Error)

When using Mysql+ibatis for insertion testing, error: Information is as follows:

Test Insert Com.ibatis.common.jdbc.exception.NestedSQLException:---The error occurred in com/study/ibatis/Student.xml.---The error occurred whileapplying a parameter map. ---Check the addstudent-Inlineparametermap. ---Check The statement (update failed). ---Cause:com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException:Duplicate entry ' 1 ' forKey ' PRIMARY 'At com.ibatis.sqlmap.engine.mapping.statement.MappedStatement.executeUpdate (Mappedstatement.java:107) at Com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.insert (Sqlmapexecutordelegate.java:393) at Com.ibatis.sqlmap.engine.impl.SqlMapSessionImpl.insert (Sqlmapsessionimpl.java:82) at Com.ibatis.sqlmap.engine.impl.SqlMapClientImpl.insert (Sqlmapclientimpl.java:58) at Com.study.ibatis.StudentDaoImpl.addStudent (Studentdaoimpl.java:33) at Com.study.ibatis.TestIbatis.main (Testibatis.java:14) caused By:com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException:Duplicate entry' 1 ' forKey ' PRIMARY 'At Sun.reflect.NativeConstructorAccessorImpl.newInstance0 (Native Method) at sun.reflect.NativeConstructorAcces Sorimpl.newinstance (Nativeconstructoraccessorimpl.java:39) at Sun.reflect.DelegatingConstructorAccessorImpl.newInstance (Delegatingconstructoraccessorimpl.java:27) at Java.lang.reflect.Constructor.newInstance (Constructor.java:513) at Com.mysql.jdbc.Util.handleNewInstance (Util.java:406) at Com.mysql.jdbc.Util.getInstance (Util.java:381) at Com.mysql.jdbc.SQLError.createSQLException (Sqlerror.java:1015) at Com.mysql.jdbc.SQLError.createSQLException (Sqlerror.java:956) at Com.mysql.jdbc.MysqlIO.checkErrorPacket (Mysqlio.java:3491) at Com.mysql.jdbc.MysqlIO.checkErrorPacket (Mysqlio.java:3423) at Com.mysql.jdbc.MysqlIO.sendCommand (Mysqlio.java:1936) at Com.mysql.jdbc.MysqlIO.sqlQueryDirect (Mysqlio.java:2060) at Com.mysql.jdbc.ConnectionImpl.execSQL (Connectionimpl.java:2542) at Com.mysql.jdbc.PreparedStatement.executeInternal (Preparedstatement.java:1734) at Com.mysql.jdbc.PreparedStatement.execute (Preparedstatement.java:995) at Com.ibatis.sqlmap.engine.execution.SqlExecutor.executeUpdate (Sqlexecutor.java:80) at Com.ibatis.sqlmap.engine.mapping.statement.MappedStatement.sqlExecuteUpdate (Mappedstatement.java:216) at Com.ibatis.sqlmap.engine.mapping.statement.MappedStatement.executeUpdate (Mappedstatement.java:94)    ... 5 Morefalse

Error means: Repeat input "1" key for "main" into the database, query table tbl_student, found three records, one of the primary key is 1. Given that I was testing, the default primary key in the database was 1. So delete the record with the primary key 1 in the database. Then the test was passed.

Summary: The primary key in Ibatis is set to the default of 1. Causes the test to start directly from the default of 1. Then an error is made, and setting the primary key default value to null resolves the problem.

Duplicate entry ' 1 ' for key ' PRIMARY ' (Error)