When Windows cannot detect a second monitor, first check whether the physical connection is normal, including power supply, cable plug-in and interface compatibility, and try to replace the cable or adapter; secondly, update or reinstall the graphics card driver through the Device Manager, and roll back the driver version if necessary; then manually click "Detection" in the display settings to identify the monitor to confirm whether it is correctly identified by the system; finally check whether the monitor input source is switched to the corresponding interface, and confirm whether the graphics card output port connected to the cable is correct. Following the above steps to check in turn, most dual-screen recognition problems can usually be solved.

MySQL query performance optimization needs to start from the core points, including rational use of indexes, optimization of SQL statements, table structure design and partitioning strategies, and utilization of cache and monitoring tools. 1. Use indexes reasonably: Create indexes on commonly used query fields, avoid full table scanning, pay attention to the combined index order, do not add indexes in low selective fields, and avoid redundant indexes. 2. Optimize SQL queries: Avoid SELECT*, do not use functions in WHERE, reduce subquery nesting, and optimize paging query methods. 3. Table structure design and partitioning: select paradigm or anti-paradigm according to read and write scenarios, select appropriate field types, clean data regularly, and consider horizontal tables to divide tables or partition by time. 4. Utilize cache and monitoring: Use Redis cache to reduce database pressure and enable slow query

To expose Docker container ports, the host needs to access the container service through port mapping. 1. Use the dockerrun-p[host_port]:[container_port] command to run the container, such as dockerrun-p8080:3000my-web-app; 2. Use the EXPOSE instruction to mark the purpose in the Dockerfile, such as EXPOSE3000, but the port will not be automatically published; 3. Configure the ports segment of the yml file in DockerCompose, such as ports:-"8080:3000"; 4. Use dockerps to check whether the port map is generated after running.

CTEs are a feature introduced by MySQL8.0 to improve the readability and maintenance of complex queries. 1. CTE is a temporary result set, which is only valid in the current query, has a clear structure, and supports duplicate references; 2. Compared with subqueries, CTE is more readable, reusable and supports recursion; 3. Recursive CTE can process hierarchical data, such as organizational structure, which needs to include initial query and recursion parts; 4. Use suggestions include avoiding abuse, naming specifications, paying attention to performance and debugging methods.

When encountering the problem of printing task stuck, clearing the print queue and restarting the PrintSpooler service is an effective solution. First, open the "Device and Printer" interface to find the corresponding printer, right-click the task and select "Cancel" to clear a single task, or click "Cancel all documents" to clear the queue at one time; if the queue is inaccessible, press Win R to enter services.msc to open the service list, find "PrintSpooler" and stop it before starting the service. If necessary, you can manually delete the residual files under the C:\Windows\System32\spool\PRINTERS path to completely solve the problem.

The key to debugging code with VSCode in Docker containers is to configure the development environment and connection methods. 1. Prepare a mirror with development tools, install necessary dependencies such as debugpy or node, and use the official devcontainers image to simplify configuration; 2. Mount the source code and enable the Remote-Containers plug-in, create .devcontainer folders and configuration files, and realize in-container development; 3. Configure the debugger, add debug settings for the corresponding language in launch.json, and enable the listening port in the code; 4. Solve common problems, such as exposing the debug port, ensuring the host is 0.0.0.0, and use postCreateC

When encountering the problem of "Windowscan'tconnecttothisnetwork", you should first check whether the network name and password are correct, including case, spaces and special characters. If it is a Chinese WiFi name, try to change it to English, and then forget the network and reconnect; secondly, check whether the router limits the number of devices or enables MAC address filtering, and restart the router or log in to the background to adjust the settings; thirdly, check the system network settings and drivers, update the wireless network card driver, reset the network settings or confirm that the IP is automatically obtained; finally check whether the network authentication method is compatible, especially in enterprise or campus networks, you need to consult the administrator to configure the correct EAP protocol and installation certificate.

MySQL's EXPLAIN is a tool used to analyze query execution plans. You can view the execution process by adding EXPLAIN before the SELECT query. 1. The main fields include id, select_type, table, type, key, Extra, etc.; 2. Efficient query needs to pay attention to type (such as const, eq_ref is the best), key (whether to use the appropriate index) and Extra (avoid Usingfilesort and Usingtemporary); 3. Common optimization suggestions: avoid using functions or blurring the leading wildcards for fields, ensure the consistent field types, reasonably set the connection field index, optimize sorting and grouping operations to improve performance and reduce capital