How to sort database records in Golang?

In Golang, query results can be sorted by using the ORDER BY clause in the database/sql package. Syntax: func (db *DB) Query(query string, args ...interface{}) (*Rows, error) Sorting example: SELECT * FROM users ORDER BY name ASC Other sorting options: DESC (descending), multiple columns (Comma separated), NULL value sort order (NULLS FIRST or NULLS LAST) Practical case: Sort orders in descending order by "order_date": SELECT * FROM orders ORDER BY order_date DESC.

How to sort database records in Golang?

When using the database/sql package to operate the database in Golang, you can use the ORDER BY clause to sort the query results.

Syntax:

func (db *DB) Query(query string, args ...interface{}) (*Rows, error)

Sort example:

The following example shows how to sort the Records sorted by "name" column in ascending order:

package main

import (
    "database/sql"
    "fmt"

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

func main() {
    // 连接到数据库
    db, err := sql.Open("mysql", "user:password@tcp(127.0.0.1:3306)/database")
    if err != nil {
        panic(err)
    }
    defer db.Close()

    // 构建查询
    query := `SELECT * FROM users ORDER BY name ASC`

    // 执行查询
    rows, err := db.Query(query)
    if err != nil {
        panic(err)
    }
    defer rows.Close()

    // 遍历结果
    for rows.Next() {
        var id int
        var name, email string
        if err := rows.Scan(&id, &name, &email); err != nil {
            panic(err)
        }
        fmt.Printf("%d %s %s\n", id, name, email)
    }
}

Other sorting options:

• DESC: Sort in descending order
• Multiple columns: Use commas to separate multiple columns, for example: ORDER BY name DESC, age ASC
• NULL value: Use NULLS FIRST or NULLS LAST Specifies whether to place NULL values ​​at the beginning or end of the result set

Practical case:

Suppose we have an "orders" table with columns "order_id", "customer_id" and "order_date". We can write a Golang program to sort orders by "order_date" in descending order:

package main

import (
    "database/sql"
    "fmt"

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

func main() {
    // 连接到数据库
    db, err := sql.Open("mysql", "user:password@tcp(127.0.0.1:3306)/database")
    if err != nil {
        panic(err)
    }
    defer db.Close()

    // 构建查询
    query := `SELECT * FROM orders ORDER BY order_date DESC`

    // 执行查询
    rows, err := db.Query(query)
    if err != nil {
        panic(err)
    }
    defer rows.Close()

    // 遍历结果
    for rows.Next() {
        var orderID, customerID int
        var orderDate string
        if err := rows.Scan(&orderID, &customerID, &orderDate); err != nil {
            panic(err)
        }
        fmt.Printf("%d %d %s\n", orderID, customerID, orderDate)
    }
}

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