单元测试涉及数据库交互的 go 函数时，可以通过以下步骤进行：设置测试数据库，如 sqlite；创建测试函数，如 getuser；编写单元测试，验证 getuser 函数的输出，覆盖不同的测试用例。
如何对涉及数据库交互的 Golang 函数进行单元测试
在编写涉及数据库交互的 Golang 函数时，进行单元测试至关重要。以下是使用 database/sql 包进行单元测试的步骤：
1. 设置测试数据库
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对于此示例，我们将使用 [SQLite](https://www.sqlite.org/) 作为测试数据库。
import (
"database/sql"
"log"
"os"
"testing"
"github.com/mattn/go-sqlite3"
)
var (
testDB *sql.DB
)
func setupTestDB(t *testing.T) {
dbPath := ":memory:"
conn, err := sqlite3.Open(dbPath)
if err != nil {
t.Fatalf("Could not open test database: %v", err)
}
testDB, err = sql.Open("sqlite3", conn)
if err != nil {
t.Fatalf("Could not connect to test database: %v", err)
}
}2. 创建测试函数
我们将创建要测试的函数：
func GetUser(id int) (*User, error) {
row := testDB.QueryRow(
"SELECT * FROM users WHERE id = ?", id,
)
var user User
err := row.Scan(&user.ID, &user.Name, &user.Email)
if err != nil {
return nil, err
}
return &user, nil
}3. 编写单元测试
现在，让我们编写一个测试函数来验证 GetUser 函数：
func TestGetUser(t *testing.T) {
setupTestDB(t)
defer testDB.Close()
// 编写测试用例
type testCase struct {
id int
input int
want *User
err bool
}
testCases := []testCase{
{id: 1, input: 1, want: &User{ID: 1, Name: "John Doe", Email: "john@example.com"}, err: false},
{id: 2, input: 2, want: nil, err: true},
}
for _, tc := range testCases {
user, err := GetUser(tc.input)
if (tc.err && err == nil) || (!tc.err && err != nil) {
t.Errorf("Expected error=%t, got %v", tc.err, err)
}
if tc.err {
continue
}
if tc.want.ID != user.ID || tc.want.Name != user.Name || tc.want.Email != user.Email {
t.Errorf("Expected result: %v, got: %v", tc.want, user)
}
}
}实战案例
以下是一份使用 database/sql 包执行单元测试的完整示例：
// test_user.go
package main
import (
"database/sql"
"log"
"os"
"testing"
"time"
_ "github.com/mattn/go-sqlite3"
)
type User struct {
ID int
Name string
Email string
Birthday time.Time
}
func setupTestDB(t *testing.T) {
dbPath := ":memory:"
conn, err := sqlite3.Open(dbPath)
if err != nil {
t.Fatalf("Could not open test database: %v", err)
}
testDB, err = sql.Open("sqlite3", conn)
if err != nil {
t.Fatalf("Could not connect to test database: %v", err)
}
_, err = testDB.Exec(
`CREATE TABLE users (
id INTEGER PRIMARY KEY,
name TEXT NOT NULL,
email TEXT UNIQUE,
birthday DATETIME
)`,
)
if err != nil {
t.Fatalf("Could not create test table: %v", err)
}
}
func TestInsertUser(t *testing.T) {
setupTestDB(t)
defer testDB.Close()
type testCase struct {
input *User
want *User
err bool
}
testCases := []testCase{
{
input: &User{Name: "John Doe", Email: "john@example.com", Birthday: time.Date(1980, time.January, 1, 0, 0, 0, 0, time.UTC)},
want: &User{ID: 1, Name: "John Doe", Email: "john@example.com", Birthday: time.Date(1980, time.January, 1, 0, 0, 0, 0, time.UTC)},
err: false,
},
{
input: &User{Name: "Jane Doe", Email: "jane@example.com", Birthday: time.Date(1990, time.March, 8, 0, 0, 0, 0, time.UTC)},
want: &User{ID: 2, Name: "Jane Doe", Email: "jane@example.com", Birthday: time.Date(1990, time.March, 8, 0, 0, 0, 0, time.UTC)},
err: false,
},
{
input: &User{Name: "Invalid Name", Email: "invalid@email.com", Birthday: time.Date(2000, time.April, 1, 0, 0, 0, 0, time.UTC)},
want: nil,
err: true,
},
}
for _, tc := range testCases {
user, err := InsertUser(tc.input)
if (tc.err && err == nil) || (!tc.err && err != nil) {
t.Errorf("Expected error=%t, got %v", tc.err, err)
}
if tc.err {
continue
}
if tc.want.ID != user.ID || tc.want.Name != user.Name || tc.want.Email != user.Email || tc.want.Birthday != user.Birthday { 
