How to perform a SELECT query in Go to fetch data from an SQL database?

To perform a SELECT query in Go to fetch data from an SQL database, you can use the database/sql package along with the appropriate database driver. Here's an example:

Install the required database driver:
- For MySQL: go get github.com/go-sql-driver/mysql
- For PostgreSQL: go get github.com/lib/pq
Import the required packages:

import (
    "database/sql"
    _ "github.com/go-sql-driver/mysql" // MySQL driver
    // _ "github.com/lib/pq" // PostgreSQL driver
)

Establish a database connection:

db, err := sql.Open("mysql", "user:password@tcp(localhost:3306)/database")
// db, err := sql.Open("postgres", "postgres://user:password@localhost/database?sslmode=disable")
if err != nil {
    panic(err.Error())
}
defer db.Close()

Execute the SELECT query:

rows, err := db.Query("SELECT * FROM table_name")
if err != nil {
    panic(err.Error())
}
defer rows.Close()

Iterate over the result set and handle the retrieved data:

for rows.Next() {
    var col1, col2 string
    if err := rows.Scan(&col1, &col2); err != nil { // Specify column types based on your table structure
        panic(err.Error())
    }
    // Handle retrieved data
    fmt.Println(col1, col2)
}
if err := rows.Err(); err != nil {
    panic(err.Error())
}

That's it! This is a basic example of how to perform a SELECT query in Go to fetch data from an SQL database. Remember to modify the connection string (sql.Open()) and column types (rows.Scan()) according to your specific setup.