这里说的是innodb类型的死锁！
网上找了好多东西 各种命令查看死锁信息，后面这条能用：
show engine innodb status;（根据mysql版本而异）
这命令在mysql命令行执行后如果有死锁
会出现下面这一块：
————————
LATEST DETECTED DEADLOCK
————————
然后你可以根据这块内容找到你引起死锁的语句。
然后解决它，
我这次的死锁是因为，
有这么一条语句
update 表名 set xx=xxx where xxx=xxx！
其中xxx没有索引！
innodb是行级锁，但是mysql的机制是用索引来找到该行，如果你那个where字段没有索引，那么mysql就找不到那一行，就会锁整张表了
这样后面的访问就会引发死锁！
给xxx字段加上索引
解决问题。
附上异常信息：
Caused by: org.springframework.dao.DeadlockLoserDataAccessException: SqlMapClient operation; SQL [];
— The error occurred while applying a parameter map.
— Check the point.updatePointAccount-InlineParameterMap.
— Check the statement (update failed).
— Cause: com.mysql.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction; nested exception is com.ibatis.common.jdbc.exception.NestedSQLException:
— The error occurred while applying a parameter map.
— Check the point.updatePointAccount-InlineParameterMap.
— Check the statement (update failed).
— Cause: com.mysql.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.translate(SQLErrorCodeSQLExceptionTranslator.java:300)
at org.springframework.orm.ibatis.SqlMapClientTemplate.execute(SqlMapClientTemplate.java:212)
at org.springframework.orm.ibatis.SqlMapClientTemplate.update(SqlMapClientTemplate.java:411)
at com.hsd.popularize.dao.BaseDaoImpl.update(BaseDaoImpl.java:162)
… 87 more
Caused by: com.ibatis.common.jdbc.exception.NestedSQLException:
— The error occurred while applying a parameter map.
— Check the point.updatePointAccount-InlineParameterMap.
— Check the statement (update failed).
— Cause: com.mysql.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
at com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.executeUpdate(GeneralStatement.java:91)
at com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelegate.update(SqlMapExecutorDelegate.java:505)
at com.ibatis.sqlmap.engine.impl.SqlMapSessionImpl.update(SqlMapSessionImpl.java:90)
at org.springframework.orm.ibatis.SqlMapClientTemplate$10.doInSqlMapClient(SqlMapClientTemplate.java:413)
at org.springframework.orm.ibatis.SqlMapClientTemplate.execute(SqlMapClientTemplate.java:209)
… 89 more
Caused by: com.mysql.jdbc.exceptions.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:941)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2870)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1573)
at com.mysql.jdbc.ServerPreparedStatement.serverExecute(ServerPreparedStatement.java:1169)
at com.mysql.jdbc.ServerPreparedStatement.executeInternal(ServerPreparedStatement.java:693)
at com.mysql.jdbc.PreparedStatement.execute(PreparedStatement.java:794)
at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.execute(NewProxyPreparedStatement.java:989)
at sun.reflect.GeneratedMethodAccessor51.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.ibatis.common.jdbc.logging.PreparedStatementLogProxy.invoke(PreparedStatementLogProxy.java:62)
at com.sun.proxy.$Proxy20.execute(Unknown Source)
at com.ibatis.sqlmap.engine.execution.SqlExecutor.executeUpdate(SqlExecutor.java:81)
at com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.sqlExecuteUpdate(GeneralStatement.java:200)
at com.ibatis.sqlmap.engine.mapping.statement.GeneralStatement.executeUpdate(GeneralStatement.java:78)
… 93 more
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