Using bufio.Scanner is the most common and efficient method in Go to read files line by line, and is suitable for handling scenarios such as large files, log parsing or configuration files. 1. Open the file using os.Open and make sure to close the file via deferfile.Close(). 2. Create a scanner instance through bufio.NewScanner. 3. Call scanner.Scan() in the for loop to read line by line until false is returned to indicate that the end of the file is reached or an error occurs. 4. Use scanner.Text() to get the current line content (excluding newline characters). 5. Check scanner.Err() after the loop is over to catch possible read errors. This method has memory effect

When you cannot connect to the MySQL database, you should first check the connection string format and driver version. 1. Check whether the connection string format is correct. Common errors include port number, database name, parameter symbol errors and driver prefix errors. It is recommended to use the generation tool to verify the format and pay attention to escaping special characters; 2. Ensure that the correct JDBC or database driver is used, different drivers are used in different languages. Pay attention to version compatibility, dependency configuration and driver class name changes, and check the log to confirm whether the driver is loading successfully; 3. Check remote access permissions and firewall settings, including MySQL user permissions, bind-address configuration and server firewall rules, and need to open port 3306 and remote access permissions; 4. Use a simple test program to quickly verify the connection.

Routing in Go applications depends on project complexity. 1. The standard library net/httpServeMux is suitable for simple applications, without external dependencies and is lightweight, but does not support URL parameters and advanced matching; 2. Third-party routers such as Chi provide middleware, path parameters and nested routing, which is suitable for modular design; 3. Gin has excellent performance, built-in JSON processing and rich functions, which is suitable for APIs and microservices. It should be selected based on whether flexibility, performance or functional integration is required. Small projects use standard libraries, medium and large projects recommend Chi or Gin, and finally achieve smooth expansion from simple to complex.

The answer is: Go applications do not have a mandatory project layout, but the community generally adopts a standard structure to improve maintainability and scalability. 1.cmd/ stores the program entrance, each subdirectory corresponds to an executable file, such as cmd/myapp/main.go; 2.internal/ stores private code, cannot be imported by external modules, and is used to encapsulate business logic and services; 3.pkg/ stores publicly reusable libraries for importing other projects; 4.api/ optionally stores OpenAPI, Protobuf and other API definition files; 5.config/, scripts/, and web/ store configuration files, scripts and web resources respectively; 6. The root directory contains go.mod and go.sum

Go provides encoding/json packages to easily process JSON data. 1. Use json.Marshal to encode the Go structure or map into JSON. The structure field must start with capital letters and the key name can be specified through the json: "name" tag. Omitempty can make the zero value field omitted; 2. Use json.Unmarshal to decode the JSON data into the Go variable, and the variable pointer must be passed in order to modify the value; 3. For JSON with unknown structure, it can be decoded into map[string]interface{} or interface{}, but type assertions are required when accessing; 4. Handle large JSO

The core methods for realizing MySQL data blood ties tracking include: 1. Use Binlog to record the data change source, enable and analyze binlog, and trace specific business actions in combination with the application layer context; 2. Inject blood ties tags into the ETL process, and record the mapping relationship between the source and the target when synchronizing the tool; 3. Add comments and metadata tags to the data, explain the field source when building the table, and connect to the metadata management system to form a visual map; 4. Pay attention to primary key consistency, avoid excessive dependence on SQL analysis, version control data model changes, and regularly check blood ties data to ensure accurate and reliable blood ties tracking.

In Go, constants are declared using the const keyword, and the value cannot be changed, and can be of no type or type; 1. A single constant declaration such as constPi=3.14159; 2. Multiple constant declarations in the block are such as const(Pi=3.14159; Language="Go"; IsCool=true); 3. Explicit type constants such as constSecondsInMinuteint=60; 4. Use iota to generate enumeration values, such as const(Sunday=iota;Monday;Tuesday) will assign values 0, 1, and 2 in sequence, and iota can be used for expressions such as bit operations; constants must determine the value at compile time,

Go's flag package can easily parse command line parameters. 1. Use flag.Type() to define type flags such as strings, integers, and booleans; 2. You can parse flags to variables through flag.TypeVar() to avoid pointer operations; 3. After calling flag.Parse(), use flag.Args() to obtain subsequent positional parameters; 4. Implementing the flag.Value interface can support custom types to meet most simple CLI requirements. Complex scenarios can be replaced by spf13/cobra library.