Cause: com. mysal.ci, idbc,exceptions.Mys0ITransactionRollbackException: lock wait timeout exceeded; try restarting transaction

引用和中提到的错误信息"Lock wait timeout exceeded; try restarting transaction"是由于在数据库操作时发生了超时导致的。这个错误通常表示在一个事务中等待锁的时间超过了设置的超时时间。可以尝试重新启动事务来解决这个问题。

引用中提到的解决方法是查看数据库中是否存在死锁。可以使用以下SQL语句查询InnoDB的事务信息来检查是否有死锁发生：

SELECT * FROM information_schema.INNODB_TRX

引用提供了一个参考链接，其中包含了解决这个问题的具体步骤。你可以参考这个链接中的内容，按照步骤一步一步解决这个问题。

综上所述，当出现错误"com.mysql.cj.jdbc.exceptions.MySQLTransactionRollbackException: Lock wait timeout exceeded; try restarting transaction"时，你可以尝试重新启动事务，并且查询数据库中是否存在死锁情况。如果需要更详细的解决方法，可以参考提供的参考链接。<span class="em">1</span><span class="em">2</span><span class="em">3</span><span class="em">4</span>

相关问题

com mysgl.ci.idbc,exceptions.commnicationsException:Communications link failure

The error message "com mysgl.ci.idbc.exceptions.communicationsException: Communications link failure" is a typical exception encountered in Java or a similar programming language when working with database connectivity libraries, specifically the one named 'idbc'. The `communicationsException` suggests that there's an issue with the communication between your application and the database.

Here's a general interpretation of the error:

1. **Exception class**: `com.mysgl.ci.idbc.exceptions.CommunicationsException` refers to a custom-defined exception thrown by the 'idbc' library, likely related to the library's networking or data transmission functionality.

2. **Cause**: A `CommunicationsLinkFailure` usually indicates that there's a problem with the connection to the database server. This can be due to network issues (like a disconnected network, firewall blocking, server down), authentication problems, timeouts, or hardware failures.

3. **Actions**: To resolve this issue, you would need to:
- Check network connectivity and ensure the database server is running.
- Verify the database credentials (username, password, host, port) used in your code are correct.
- If using a connection pool, make sure it's configured properly and not exhausted.
- Investigate any network configuration or firewall settings that might be interfering with the connection.
- Add appropriate error handling and retry logic, if applicable.

找出下列Java类中存在的错误，并说明错误原因import java.sal.*; //省略类和main()方法代码 Connection conn = null; PreparedStatement pstmt= null; ResultSet rs = null; try { Class.forName("com.mysql.cj.idbc.Driver"); }catch (ClassNotEoundException e){ e.printStackTrace(); } try { conn = DriverManager.getConnection( "idbc:mysal://llocalhost:3306/myschool","root","root"); String sqlStr= "SELECT max(id) FROM student "; pstmt = conn.prepareStatement(sqlStr); rs=pstmt.executeQuery(); System.out.println(rs.getlnt(1)); }catch(SQLException e){e.printStackTrace(); }finally { try { if (null != rs) rs.colse(); if (null l= pstmt) pstmt.close(); if (null != conn) conn.close(); }catch(SQLException e){e.printStackTrace();} }

该Java类存在以下错误：

1. `java.sal.*` 库的导入语句中，应该为 `java.sql.*`，而不是 `java.sal.*`。

2. `Class.forName("com.mysql.cj.idbc.Driver");` 中的 `idbc` 应该为 `jdbc`。

3. `rs.getlnt(1)` 中的 `getlnt` 应该为 `getInt`。

4. `rs.colse()` 中的 `colse` 应该为 `close`。

错误原因：

1. `java.sal.*` 库是不存在的，应该使用正确的库名 `java.sql.*`。

2. `Class.forName()` 用于加载数据库驱动程序，而MySQL的驱动程序是 `com.mysql.cj.jdbc.Driver`，而不是 `com.mysql.cj.idbc.Driver`。另外，`idbc` 应该为 `jdbc`。

3. `rs.getlnt(1)` 中的 `getlnt` 是拼写错误，应该为 `getInt`。

4. `rs.colse()` 中的 `colse` 是拼写错误，应该为 `close`，用于关闭 ResultSet 对象。

综上所述，正确的代码应该为：

import java.sql.*;
//省略类和main()方法代码
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
try {
    Class.forName("com.mysql.cj.jdbc.Driver");
} catch (ClassNotFoundException e) {
    e.printStackTrace();
}
try {
    conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/myschool", "root", "root");
    String sqlStr = "SELECT max(id) FROM student ";
    pstmt = conn.prepareStatement(sqlStr);
    rs = pstmt.executeQuery();
    System.out.println(rs.getInt(1));
} catch (SQLException e) {
    e.printStackTrace();
} finally {
    try {
        if (null != rs) rs.close();
        if (null != pstmt) pstmt.close();
        if (null != conn) conn.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}