Learn database functions in Go language and implement add, delete, modify and query operations on MySQL data

Learn the database functions in Go language and implement the addition, deletion, modification and query operations of MySQL data

Go language is an efficient, concise and highly efficient programming language, and the database is used to store and manage data important tool. In Go language, there are many database drivers, one of the most commonly used is MySQL. This article will introduce how to learn database functions in Go language, and use code examples to show how to implement addition, deletion, modification and query operations of MySQL data.

Before starting to learn, we need to ensure that the Go language and MySQL have been installed, and the MySQL driver has been imported. You can use the following command to install the MySQL driver:

go get -u github.com/go-sql-driver/mysql

Next, we will create a database named "db_test" and create a data table named "users" in it to demonstrate the addition. Delete, modify and check operations. You can use the following code to create databases and data tables:

package main

import (
    "database/sql"
    "fmt"

    _ "github.com/go-sql-driver/mysql"
)

func main() {
    db, err := sql.Open("mysql", "root:password@tcp(127.0.0.1:3306)/")
    if err != nil {
        panic(err.Error())
    }

    defer db.Close()

    _, err = db.Exec("CREATE DATABASE IF NOT EXISTS db_test")
    if err != nil {
        panic(err.Error())
    }

    _, err = db.Exec("USE db_test")
    if err != nil {
        panic(err.Error())
    }

    _, err = db.Exec("CREATE TABLE IF NOT EXISTS users (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(20))")
    if err != nil {
        panic(err.Error())
    }

    fmt.Println("Database and table created successfully!")
}

Run the above code to create a database named "db_test" and a data table named "users" in MySQL.

Next, we will implement the add, delete, modify and check operations. First, we will implement the function of inserting data. This can be achieved using the following code:

func insertUser(db *sql.DB, name string) {
    stmt, err := db.Prepare("INSERT INTO users(name) VALUES(?)")
    if err != nil {
        panic(err.Error())
    }

    _, err = stmt.Exec(name)
    if err != nil {
        panic(err.Error())
    }

    fmt.Println("User inserted successfully!")
}

Next, we will implement the function of deleting data. This can be achieved using the following code:

func deleteUser(db *sql.DB, id int) {
    stmt, err := db.Prepare("DELETE FROM users WHERE id = ?")
    if err != nil {
        panic(err.Error())
    }

    _, err = stmt.Exec(id)
    if err != nil {
        panic(err.Error())
    }

    fmt.Println("User deleted successfully!")
}

Then, we will implement the function of updating data. This can be achieved using the following code:

func updateUser(db *sql.DB, id int, name string) {
    stmt, err := db.Prepare("UPDATE users SET name = ? WHERE id = ?")
    if err != nil {
        panic(err.Error())
    }

    _, err = stmt.Exec(name, id)
    if err != nil {
        panic(err.Error())
    }

    fmt.Println("User updated successfully!")
}

Finally, we will implement the function of querying data. This can be achieved using the following code:

func queryUsers(db *sql.DB) {
    rows, err := db.Query("SELECT * FROM users")
    if err != nil {
        panic(err.Error())
    }

    defer rows.Close()

    var id int
    var name string

    fmt.Println("Users:")
    for rows.Next() {
        err := rows.Scan(&id, &name)
        if err != nil {
            panic(err.Error())
        }

        fmt.Printf("ID: %d, Name: %s
", id, name)
    }
}

Now, we can integrate the above functions into a complete example and test it as follows:

package main

import (
    "database/sql"
    "fmt"

    _ "github.com/go-sql-driver/mysql"
)

func insertUser(db *sql.DB, name string) {
    stmt, err := db.Prepare("INSERT INTO users(name) VALUES(?)")
    if err != nil {
        panic(err.Error())
    }

    _, err = stmt.Exec(name)
    if err != nil {
        panic(err.Error())
    }

    fmt.Println("User inserted successfully!")
}

func deleteUser(db *sql.DB, id int) {
    stmt, err := db.Prepare("DELETE FROM users WHERE id = ?")
    if err != nil {
        panic(err.Error())
    }

    _, err = stmt.Exec(id)
    if err != nil {
        panic(err.Error())
    }

    fmt.Println("User deleted successfully!")
}

func updateUser(db *sql.DB, id int, name string) {
    stmt, err := db.Prepare("UPDATE users SET name = ? WHERE id = ?")
    if err != nil {
        panic(err.Error())
    }

    _, err = stmt.Exec(name, id)
    if err != nil {
        panic(err.Error())
    }

    fmt.Println("User updated successfully!")
}

func queryUsers(db *sql.DB) {
    rows, err := db.Query("SELECT * FROM users")
    if err != nil {
        panic(err.Error())
    }

    defer rows.Close()

    var id int
    var name string

    fmt.Println("Users:")
    for rows.Next() {
        err := rows.Scan(&id, &name)
        if err != nil {
            panic(err.Error())
        }

        fmt.Printf("ID: %d, Name: %s
", id, name)
    }
}

func main() {
    db, err := sql.Open("mysql", "root:password@tcp(127.0.0.1:3306)/db_test")
    if err != nil {
        panic(err.Error())
    }

    defer db.Close()

    insertUser(db, "Alice")
    insertUser(db, "Bob")
    insertUser(db, "Charlie")

    queryUsers(db)

    deleteUser(db, 2)

    queryUsers(db)

    updateUser(db, 1, "Alex")

    queryUsers(db)
}

Run the above code to achieve Add, delete, modify and query MySQL data. By learning the database functions in the Go language, we can easily operate MySQL data and realize various functional requirements. I believe that through the code examples provided in this article, readers can have a deeper understanding and mastery of the use of Go language and MySQL database.

The above is the detailed content of Learn database functions in Go language and implement add, delete, modify and query operations on MySQL data. For more information, please follow other related articles on the PHP Chinese website!