mysql 的一個死結問題解決，mysql死結解決

mysql 的一個死結問題解決，mysql死結解決

這裡說的是innodb類型的死結！

網上找了好多東西 各種命令查看死結資訊，後面這條能用：

show engine innodb status;（根據mysql版本而異）

這命令在mysql命令列執行後如果有死結

會出現下面這一塊：

------------------------
LATEST DETECTED DEADLOCK
------------------------

然後你可以根據這塊內容找到你引起死結的語句。

然後解決它，

我這次的死結是因為，

有這麼一條語句

update 表名 set xx=xxx where xxx=xxx！

其中xxx沒有索引！

innodb是行級鎖，但是mysql的機制是用索引來找到該行，如果你那個where欄位沒有索引，那麼mysql就找不到那一行，就會鎖整張表了

這樣後面的訪問就會引發死結！

給xxx欄位加上索引

解決問題。

附上異常資訊：

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