feat(Go-StudyExample):2021/02/23:新增linq包使用示例
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@@ -0,0 +1,127 @@
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/*
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* @Author : huangzj
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* @Time : 2020/11/12 14:04
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* @Description:
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*/
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package linqUse
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import "time"
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type Book struct {
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Name string
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Author string
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Money float64
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WordsNum int
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PublishTime time.Time
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}
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func MakeBook() []Book {
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bookList := make([]Book, 0)
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bookList = append(bookList, Book{
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Name: "Go语言",
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Author: "Go",
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Money: 100,
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WordsNum: 1000,
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PublishTime: time.Date(2020, 1, 1, 10, 0, 0, 0, time.Local),
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})
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bookList = append(bookList, Book{
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Name: "Effective Java",
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Author: "Java",
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Money: 78,
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WordsNum: 9000,
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PublishTime: time.Date(2020, 2, 15, 10, 0, 0, 0, time.Local),
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})
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bookList = append(bookList, Book{
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Name: "Java语言",
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Author: "Java",
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Money: 50,
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WordsNum: 3000,
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PublishTime: time.Date(2020, 2, 1, 10, 0, 0, 0, time.Local),
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})
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bookList = append(bookList, Book{
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Name: "Lua语言",
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Author: "Lua",
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Money: 75,
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WordsNum: 45000,
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PublishTime: time.Date(2020, 1, 10, 10, 0, 0, 0, time.Local),
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})
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bookList = append(bookList, Book{
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Name: "React语言",
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Author: "React",
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Money: 99,
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WordsNum: 14500,
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PublishTime: time.Date(2020, 7, 1, 10, 0, 0, 0, time.Local),
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})
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bookList = append(bookList, Book{
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Name: "Red语言",
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Author: "Red",
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Money: 28,
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WordsNum: 880,
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PublishTime: time.Date(2019, 4, 1, 10, 0, 0, 0, time.Local),
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})
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bookList = append(bookList, Book{
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Name: "JavaScript语言",
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Author: "JavaScript",
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Money: 81,
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WordsNum: 3776,
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PublishTime: time.Date(2019, 5, 17, 10, 0, 0, 0, time.Local),
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})
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return bookList
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}
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func MakeBook1() []Book {
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bookList := make([]Book, 0)
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bookList = append(bookList, Book{
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Name: "Go语言",
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Author: "Go",
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Money: 100,
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WordsNum: 1000,
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PublishTime: time.Date(2020, 1, 1, 10, 0, 0, 0, time.Local),
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})
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bookList = append(bookList, Book{
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Name: "Effective Java",
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Author: "Java",
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Money: 78,
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WordsNum: 9000,
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PublishTime: time.Date(2020, 2, 15, 10, 0, 0, 0, time.Local),
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})
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bookList = append(bookList, Book{
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Name: "Go语言(第二版)",
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Author: "Go",
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Money: 50,
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WordsNum: 3000,
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PublishTime: time.Date(2020, 2, 1, 10, 0, 0, 0, time.Local),
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})
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return bookList
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}
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func MakeBook2() []Book {
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bookList := make([]Book, 0)
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bookList = append(bookList, Book{
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Name: "Go语言",
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Author: "Go",
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Money: 100,
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WordsNum: 1000,
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PublishTime: time.Date(2020, 1, 1, 10, 0, 0, 0, time.Local),
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})
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return bookList
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}
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func MakeBook3() []Book {
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bookList := make([]Book, 0)
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bookList = append(bookList, Book{
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Name: "Go语言",
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Author: "Go",
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Money: 100,
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WordsNum: 1000,
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PublishTime: time.Date(2020, 1, 1, 10, 0, 0, 0, time.Local),
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})
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bookList = append(bookList, Book{
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Name: "Go语言(第三版)",
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Author: "Go",
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Money: 50,
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WordsNum: 3000,
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PublishTime: time.Date(2020, 2, 1, 10, 0, 0, 0, time.Local),
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})
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return bookList
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}
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@@ -0,0 +1,57 @@
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/*
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* @Author : huangzj
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* @Time : 2020/11/24 16:17
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* @Description:
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*/
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package linqUse
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type Person struct {
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Name string //拥有者的名字
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}
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type Pet struct {
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Name string //动物的名字
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OwnerName string //拥有者的名字
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}
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type Man struct {
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Name string //拥有者的名字
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Pets []Pets //宠物们
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}
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type Pets struct {
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Name string //动物的名字
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}
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func MakeInnerData() []Man {
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man := make([]Man, 0)
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man = append(man, Man{
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Name: "康康",
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Pets: []Pets{{Name: "康康的狗"}, {Name: "康康的猫"}},
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})
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man = append(man, Man{
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Name: "老施",
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Pets: []Pets{{Name: "老施的🐟"}, {Name: "老施的鸟"}},
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})
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man = append(man, Man{
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Name: "小明",
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Pets: []Pets{{Name: "小明的🐖"}, {Name: "小明的狗"}},
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})
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return man
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}
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func MakeJoinData() ([]Person, []Pet) {
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kangkang := Person{Name: "爱吃合合乐的康康"}
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laoshi := Person{Name: "老施"}
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xiaoming := Person{Name: "不要催-小明"}
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expect := Person{Name: "我是没有宠物的人"}
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dog := Pet{Name: "康康的狗", OwnerName: kangkang.Name}
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cat := Pet{Name: "康康的猫", OwnerName: kangkang.Name}
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fish := Pet{Name: "老施的🐟", OwnerName: laoshi.Name}
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pig := Pet{Name: "小明的🐖", OwnerName: xiaoming.Name}
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return []Person{kangkang, laoshi, xiaoming, expect}, []Pet{dog, cat, fish, pig}
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}
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@@ -0,0 +1,41 @@
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/*
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* @Author : huangzj
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* @Time : 2020/11/12 14:43
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* @Description:测试方法集合
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*/
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package linqUse
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import "time"
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//书籍发布时间是否早于--.--.--
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var PublishTimeBeforeFunc = func(thisBook interface{}) bool {
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if thisBook.(Book).PublishTime.Before(time.Date(2019, 1, 1, 0, 0, 0, 0, time.Local)) {
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return true
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}
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return false
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}
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//书籍发布时间是否晚于--.--.--
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var PublishTimeAfterFunc = func(thisBook interface{}) bool {
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if thisBook.(Book).PublishTime.After(time.Date(2018, 1, 1, 0, 0, 0, 0, time.Local)) {
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return true
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}
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return false
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}
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//书籍发布时间是否晚于--.--.--
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var PublishTimeAfterFunc2 = func(thisBook interface{}) bool {
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if thisBook.(Book).PublishTime.After(time.Date(2021, 1, 1, 0, 0, 0, 0, time.Local)) {
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return true
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}
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return false
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}
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//自定义聚合操作方法
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var AggregateFunc = func(first interface{}, second interface{}) interface{} {
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if first.(Book).PublishTime.Before(second.(Book).PublishTime) {
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return first
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}
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return second
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}
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@@ -0,0 +1,531 @@
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/*
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* @Author : huangzj
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* @Time : 2020/11/12 10:52
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* @Description:这边是linq包的使用操作,为之后的使用做一些示例
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* 包引用命令: go get github.com/ahmetb/go-linq
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* 示例参考地址:https://godoc.org/github.com/ahmetb/go-linq#
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* 在Idea中对应方法名上使用 Shift+F1 组合键操作可以直接跳转到方法对应的地址
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*/
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package linqUse
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import (
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"Go-Tool/util/timed"
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"fmt"
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"github.com/ahmetb/go-linq"
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"strconv"
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"testing"
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"time"
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)
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func Test(t *testing.T) {
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Aggregate() //自定义聚合操作
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All() //判断数组的所有元素是否都满足条件
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Where() //根据条件查询对应的元素
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AnyWith() //判断数组是否有任意个元素满足条件
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Calculate() //这个方法只能计算数值类型
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Combine() //组合两个数组的两种方式
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Contains() //包含
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FirstAndLast() //第一个和最后一个
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Distinct() //返回数组中唯一的元素
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Except() //返回第一个序列没有出现在第二个序列中的成员
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GroupBy() //按照对应规则进行分组
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Intersect() //产生两个数组的交集
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OrderBy() //排序
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Skip() //略过指定条件的元素
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Count() //计算数组总长度
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Result() //对结果集进行操作
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Take() //获取对应数量的元素,一般多用在排序后前几个的元素
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Select() //筛选结构体中对应的元素
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SelectMany() //对多维数组进行合并或者其他处理 对结构体中的数组进行处理(与结构体结合操作)
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Join() //对两个有关联的数据进行处理
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}
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func Where() {
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bookList := MakeBook()
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query := linq.From(bookList)
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fmt.Println()
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fmt.Println()
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query.WhereT(func(book Book) bool {
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return book.Money > float64(70)
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}).ForEachT(func(book Book) {
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fmt.Println(fmt.Sprintf("作者%v,写了一本书叫做%v", book.Author, book.Name))
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})
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}
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func Take() {
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bookList := MakeBook()
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query := linq.From(bookList)
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query.OrderByDescendingT(func(book Book) string {
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return book.Author
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}).Take(3).ForEachT(func(book Book) {
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fmt.Println(fmt.Sprintf("作者%v,写了一本书叫做%v", book.Author, book.Name))
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})
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fmt.Println()
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fmt.Println()
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//超出对应数量的元素会不会报错(输出所有的元素)
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query.OrderByDescendingT(func(book Book) string {
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return book.Author
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}).Take(100).ForEachT(func(book Book) {
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fmt.Println(fmt.Sprintf("作者%v,写了一本书叫做%v", book.Author, book.Name))
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})
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fmt.Println()
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fmt.Println()
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//负数会发生什么情况(直接返回,不做操作)
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query.OrderByDescendingT(func(book Book) string {
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return book.Author
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}).Take(-2).ForEachT(func(book Book) {
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fmt.Println(fmt.Sprintf("作者%v,写了一本书叫做%v", book.Author, book.Name))
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})
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//TakeWhile系列的方法,虽然能够根据条件进行查询,但是有一个弊端就是一旦查询到的结果和条件不符合则直接返回,也就是说后面满足条件的元素不会再被做筛选
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//那么比如这边的这个大于的操作,就需要对整个数组进行排序之后然后进行筛选,如果不希望排序,则用原生的for循环可能会更好
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fmt.Println()
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fmt.Println()
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query.TakeWhileT(func(book Book) bool {
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return book.Money > float64(70)
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}).ForEachT(func(book Book) {
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fmt.Println(fmt.Sprintf("作者%v,写了一本书叫做%v", book.Author, book.Name))
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})
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}
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func Result() {
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bookList := MakeBook()
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query := linq.From(bookList)
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bookMap := make(map[string]string, 0)
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query.SelectT(func(book Book) linq.KeyValue {
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return linq.KeyValue{
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Key: book.Author,
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Value: book.Name,
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}
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}).ToMap(&bookMap)
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for key, value := range bookMap {
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fmt.Println(fmt.Sprintf("作者%v,写了一本书叫做%v", key, value))
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}
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fmt.Println()
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fmt.Println()
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//如果key相同的话,前面的元素会被覆盖掉(只会保留最后一个)
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bookList1 := MakeBook1()
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query1 := linq.From(bookList1)
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bookMap1 := make(map[string]string, 0)
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query1.SelectT(func(book Book) linq.KeyValue {
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return linq.KeyValue{
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Key: book.Author,
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Value: book.Name,
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}
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}).ToMap(&bookMap1)
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for key, value := range bookMap1 {
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fmt.Println(fmt.Sprintf("作者%v,写了一本书叫做%v", key, value))
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}
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fmt.Println()
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fmt.Println()
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bookList2 := MakeBook()
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query2 := linq.From(bookList2)
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|
bookMap2 := make(map[string]Book, 0)
|
||||||
|
query2.ToMapByT(&bookMap2,
|
||||||
|
//这个方法决定key的字段是什么
|
||||||
|
func(book Book) string {
|
||||||
|
return book.Author
|
||||||
|
}, //这个方法决定value的字段是什么
|
||||||
|
func(book Book) Book {
|
||||||
|
return book
|
||||||
|
})
|
||||||
|
|
||||||
|
for key, value := range bookMap2 {
|
||||||
|
fmt.Println(fmt.Sprintf("作者%v,写了一本书叫做%v", key, value.Name))
|
||||||
|
}
|
||||||
|
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println()
|
||||||
|
bookListResult := make([]Book, 0)
|
||||||
|
linq.From(MakeBook()).OrderByDescendingT(func(book Book) string {
|
||||||
|
return book.Author
|
||||||
|
}).ToSlice(&bookListResult)
|
||||||
|
for _, value := range bookListResult {
|
||||||
|
fmt.Println(fmt.Sprintf("作者%v,写了一本书叫做%v", value.Author, value.Name))
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func Count() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
fmt.Println(fmt.Sprintf("数组中发布时间早于2019-1-1的书有%d本", query.CountWithT(PublishTimeBeforeFunc)))
|
||||||
|
fmt.Println(fmt.Sprintf("数组中发布时间晚于2018-1-1的书有%d本", query.CountWithT(PublishTimeAfterFunc)))
|
||||||
|
}
|
||||||
|
|
||||||
|
func Skip() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
|
||||||
|
fmt.Println(fmt.Sprintf("跳过三个元素,返回的数组中包含%d个元素", len(query.Skip(3).Results())))
|
||||||
|
fmt.Println(fmt.Sprintf("跳过发布时间在2018.1.1之后的元素,返回的数组中包含%d个元素", query.SkipWhile(PublishTimeAfterFunc).Count()))
|
||||||
|
}
|
||||||
|
|
||||||
|
func SelectMany() {
|
||||||
|
input := [][]int{{1, 2, 3}, {4, 5, 6, 7}}
|
||||||
|
|
||||||
|
//二位数组进行合并
|
||||||
|
linq.From(input).SelectManyT(
|
||||||
|
func(i []int) linq.Query {
|
||||||
|
return linq.From(i)
|
||||||
|
},
|
||||||
|
).ForEachT(func(num int) {
|
||||||
|
fmt.Println(num)
|
||||||
|
})
|
||||||
|
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println()
|
||||||
|
|
||||||
|
//三维数组进行合并
|
||||||
|
input1 := [][][]int{{{1, 2, 3}}, {{4, 5, 6, 7}, {8, 9, 10}}}
|
||||||
|
linq.From(input1).SelectManyT(
|
||||||
|
func(i [][]int) linq.Query {
|
||||||
|
return linq.From(i)
|
||||||
|
},
|
||||||
|
).SelectManyT(
|
||||||
|
func(i []int) linq.Query {
|
||||||
|
return linq.From(i)
|
||||||
|
},
|
||||||
|
).ForEachT(func(num int) {
|
||||||
|
fmt.Print(num)
|
||||||
|
fmt.Print(" ")
|
||||||
|
})
|
||||||
|
|
||||||
|
//SelectMany的主要作用是,结构体中包含数组元素,可以把数组元素取出来和结构体做相应的操作
|
||||||
|
//如果是结构体中有多个数组的操作,可以把对应的多个数组放到一个新定义的结构体数组中
|
||||||
|
fmt.Println()
|
||||||
|
men := MakeInnerData()
|
||||||
|
linq.From(men).
|
||||||
|
//第一个方法筛选出结构体对应的数组
|
||||||
|
SelectManyByT(func(man Man) linq.Query {
|
||||||
|
return linq.From(man.Pets)
|
||||||
|
},
|
||||||
|
//第二个方法这边可以拿到数组中元素对应的结构体的数据.
|
||||||
|
func(pet Pets, man Man) map[string]Pets {
|
||||||
|
return map[string]Pets{
|
||||||
|
man.Name: pet,
|
||||||
|
}
|
||||||
|
}).ForEachT(func(petWithMan map[string]Pets) {
|
||||||
|
for key, value := range petWithMan {
|
||||||
|
fmt.Println(fmt.Sprintf("%v拥有一只宠物,它的名字叫做%v", key, value.Name))
|
||||||
|
}
|
||||||
|
})
|
||||||
|
|
||||||
|
}
|
||||||
|
|
||||||
|
func Select() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
|
||||||
|
//筛选出结构体对应的元素
|
||||||
|
query.SelectT(func(book Book) string {
|
||||||
|
return book.Name
|
||||||
|
}).ForEachT(func(bookName string) {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v", bookName))
|
||||||
|
})
|
||||||
|
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println()
|
||||||
|
|
||||||
|
//根据下标进行返回,如果是跟下标有关的,则可以通过这个方法进行组合然后返回.
|
||||||
|
query.SelectIndexedT(func(index int, book Book) []string {
|
||||||
|
return []string{strconv.Itoa(index + 1), book.Name}
|
||||||
|
}).ForEachT(func(book []string) {
|
||||||
|
fmt.Println(fmt.Sprintf("第%v本书,书名%v", book[0], book[1]))
|
||||||
|
})
|
||||||
|
}
|
||||||
|
|
||||||
|
//OrderBy可以按照对应的规则进行排序,可以实现多重排序,需要注意的就是OrderBy是从到达,orderByDescending是从大到小
|
||||||
|
func OrderBy() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
query = query.OrderByDescendingT(func(book Book) string {
|
||||||
|
return book.Name
|
||||||
|
}).ThenByDescendingT(func(book Book) string {
|
||||||
|
return book.Author
|
||||||
|
}).ThenByDescendingT(func(book Book) float64 {
|
||||||
|
return book.Money
|
||||||
|
}).Query
|
||||||
|
|
||||||
|
query.ForEachT(func(book Book) {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v,作者%v", book.Name, book.Author))
|
||||||
|
})
|
||||||
|
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println()
|
||||||
|
|
||||||
|
//reverse: 把结果逆序
|
||||||
|
query.Reverse().ForEachT(func(book Book) {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v,作者%v", book.Name, book.Author))
|
||||||
|
})
|
||||||
|
}
|
||||||
|
|
||||||
|
func Join() {
|
||||||
|
//任务和动物有关联,直接找到对应的关系,没有对应关系的数据不会处理,正常情况下应该用更单一的数据来做关联
|
||||||
|
persons, pets := MakeJoinData()
|
||||||
|
query1 := linq.From(persons)
|
||||||
|
query2 := linq.From(pets)
|
||||||
|
query1.JoinT(query2,
|
||||||
|
func(person Person) string {
|
||||||
|
return person.Name
|
||||||
|
},
|
||||||
|
func(pet Pet) string {
|
||||||
|
return pet.OwnerName
|
||||||
|
},
|
||||||
|
func(person Person, pet Pet) map[string]Pet {
|
||||||
|
petMap := make(map[string]Pet)
|
||||||
|
petMap[person.Name] = pet
|
||||||
|
return petMap
|
||||||
|
},
|
||||||
|
).ForEachT(func(petMap map[string]Pet) {
|
||||||
|
for key, value := range petMap {
|
||||||
|
fmt.Println(fmt.Sprintf("%v拥有一只宠物,它的名字叫做:%v", key, value.Name))
|
||||||
|
}
|
||||||
|
})
|
||||||
|
}
|
||||||
|
|
||||||
|
func Intersect() {
|
||||||
|
bookList1 := MakeBook1()
|
||||||
|
query1 := linq.From(bookList1)
|
||||||
|
bookList2 := MakeBook2()
|
||||||
|
query2 := linq.From(bookList2)
|
||||||
|
|
||||||
|
fmt.Println("输出对应的书籍元素,按照结构体判断交集")
|
||||||
|
query3 := query1.Intersect(query2)
|
||||||
|
query3.ForEachT(func(book Book) {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v,作者%v", book.Name, book.Author))
|
||||||
|
})
|
||||||
|
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println("输出对应的书籍元素,按照元素判断交集")
|
||||||
|
query3 = query1.IntersectByT(query2, func(book Book) string {
|
||||||
|
return book.Author
|
||||||
|
})
|
||||||
|
query3.ForEachT(func(book Book) {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v,作者%v", book.Name, book.Author))
|
||||||
|
})
|
||||||
|
|
||||||
|
//这边计算是按照结构体的一个元素进行比较。事实证明无论是否按照结构体的元素筛选,返回的都是完全相同的元素
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println("输出对应的书籍元素,按照元素判断交集2")
|
||||||
|
bookList1 = MakeBook1()
|
||||||
|
query1 = linq.From(bookList1)
|
||||||
|
bookList3 := MakeBook3()
|
||||||
|
query2 = linq.From(bookList3)
|
||||||
|
query3 = query2.IntersectByT(query1, func(book Book) string {
|
||||||
|
return book.Author
|
||||||
|
})
|
||||||
|
query3.ForEachT(func(book Book) {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v,作者%v", book.Name, book.Author))
|
||||||
|
})
|
||||||
|
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println("判断是否会不重复的处理")
|
||||||
|
query1 = linq.From([]int{1, 2, 3, 4, 5, 3})
|
||||||
|
query2 = linq.From([]int{1, 3, 3, 78, 99, 0, 111})
|
||||||
|
query3 = query2.IntersectByT(query1, func(i int) int {
|
||||||
|
return i
|
||||||
|
})
|
||||||
|
fmt.Println(query3.Results())
|
||||||
|
}
|
||||||
|
|
||||||
|
func GroupBy() {
|
||||||
|
bookList1 := MakeBook1()
|
||||||
|
query := linq.From(bookList1)
|
||||||
|
|
||||||
|
fmt.Println("输出对应书名和作者")
|
||||||
|
//第一个func是分组的依据,第二个func是分组后返回的元素.
|
||||||
|
query = query.GroupByT(func(book Book) string {
|
||||||
|
return book.Author
|
||||||
|
}, func(book Book) Book {
|
||||||
|
return book
|
||||||
|
})
|
||||||
|
|
||||||
|
query.ForEachT(func(bookGroup linq.Group) {
|
||||||
|
fmt.Println(fmt.Sprintf("作者是%v", bookGroup.Key))
|
||||||
|
for _, item := range bookGroup.Group {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v,作者%v", item.(Book).Name, item.(Book).Author))
|
||||||
|
fmt.Println()
|
||||||
|
}
|
||||||
|
|
||||||
|
})
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println("输出对应书名")
|
||||||
|
|
||||||
|
bookList1 = MakeBook1()
|
||||||
|
query = linq.From(bookList1)
|
||||||
|
var nameGroups []linq.Group
|
||||||
|
query.GroupByT(
|
||||||
|
func(book Book) string { return book.Author },
|
||||||
|
func(book Book) string { return book.Name },
|
||||||
|
).ToSlice(&nameGroups)
|
||||||
|
|
||||||
|
for _, item := range nameGroups {
|
||||||
|
fmt.Println(fmt.Sprintf("作者是%v", item.Key))
|
||||||
|
for _, row := range item.Group {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v", row))
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
func Except() {
|
||||||
|
bookList1 := MakeBook1()
|
||||||
|
query1 := linq.From(bookList1)
|
||||||
|
bookList2 := MakeBook2()
|
||||||
|
query2 := linq.From(bookList2)
|
||||||
|
|
||||||
|
fmt.Println("输出对应书名和作者")
|
||||||
|
//判断结构结构体本身是否相等
|
||||||
|
query1.Except(query2).
|
||||||
|
ForEachT(func(book Book) {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v,作者%v", book.Name, book.Author))
|
||||||
|
})
|
||||||
|
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println("输出对应书名和作者")
|
||||||
|
//判断结构体的某个字段是否出现
|
||||||
|
query1.ExceptByT(query2, func(book Book) string {
|
||||||
|
return book.Author
|
||||||
|
}).ForEachT(func(book Book) {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v,作者%v", book.Name, book.Author))
|
||||||
|
})
|
||||||
|
}
|
||||||
|
|
||||||
|
func Distinct() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
query = query.Append(Book{
|
||||||
|
Name: "Go语言",
|
||||||
|
Author: "Go",
|
||||||
|
Money: 100,
|
||||||
|
WordsNum: 1000,
|
||||||
|
PublishTime: time.Date(2020, 1, 1, 10, 0, 0, 0, time.Local),
|
||||||
|
})
|
||||||
|
bookList1 := make([]Book, 0)
|
||||||
|
query.ToSlice(&bookList1)
|
||||||
|
fmt.Println(fmt.Sprintf("筛选之前query中总共有%d个数据", query.Count()))
|
||||||
|
//这边的distinct如果是结构体,则判断的是结构体的所有值,如果是指针则判断的是指针地址.
|
||||||
|
query = query.Distinct()
|
||||||
|
fmt.Println(fmt.Sprintf("筛选之后query中总共有%d个数据", query.Count()))
|
||||||
|
|
||||||
|
fmt.Println()
|
||||||
|
fmt.Println("输出对应书名和作者")
|
||||||
|
query = query.Append(Book{
|
||||||
|
Name: "Go语言(第二版)",
|
||||||
|
Author: "Go",
|
||||||
|
Money: 100,
|
||||||
|
WordsNum: 1000,
|
||||||
|
PublishTime: time.Date(2020, 1, 1, 10, 0, 0, 0, time.Local),
|
||||||
|
})
|
||||||
|
//根据对应的规则来判断是否相同 -- 如果对应的字段一样,只会保留第一个找到的,后面的会被清除掉
|
||||||
|
query.DistinctByT(func(book Book) string {
|
||||||
|
return book.Author
|
||||||
|
}).ForEachT(func(book Book) {
|
||||||
|
fmt.Println(fmt.Sprintf("书名%v,作者%v", book.Name, book.Author))
|
||||||
|
})
|
||||||
|
}
|
||||||
|
|
||||||
|
func Combine() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
query1 := query.Concat(query) //不会排除重复项
|
||||||
|
query2 := query.Union(query) //会排除重复项
|
||||||
|
fmt.Println(fmt.Sprintf("不会排除重复项的方法返回的元素个数是%d", len(query1.Results())))
|
||||||
|
fmt.Println(fmt.Sprintf("会排除重复项的方法返回的元素个数是%d", len(query2.Results())))
|
||||||
|
query1 = query1.Append(Book{Name: "Last One"}) //加在原来的Query的最后面
|
||||||
|
query2 = query2.Prepend(Book{Name: "First One"}) //加在原来的Query的第一个
|
||||||
|
fmt.Println(fmt.Sprintf("最后一个元素是%v", query1.Last()))
|
||||||
|
fmt.Println(fmt.Sprintf("第一个元素是%v", query2.First()))
|
||||||
|
}
|
||||||
|
|
||||||
|
func FirstAndLast() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
fmt.Println(fmt.Sprintf("数组第一本书书名叫:%s", query.First().(Book).Name))
|
||||||
|
fmt.Println(fmt.Sprintf("数组第一本书发布时间在2018年1月1号之后的书书名叫:%s", query.FirstWith(PublishTimeAfterFunc).(Book).Name))
|
||||||
|
|
||||||
|
fmt.Println(fmt.Sprintf("数组最后一本书书名叫:%s", query.Last().(Book).Name))
|
||||||
|
fmt.Println(fmt.Sprintf("数组最后一本书发布时间在2018年1月1号之后的书书名叫:%s", query.LastWith(PublishTimeAfterFunc).(Book).Name))
|
||||||
|
}
|
||||||
|
|
||||||
|
func Contains() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
//这边需要注意是的是如果要判断两个元素是否相等,在go里面不能使用元素的地址
|
||||||
|
// 所以这边加到query里面的必须不能是元素的地址,否则没办法比较结构体本身,而是比较结构体的地址
|
||||||
|
fmt.Println(fmt.Sprintf("判断当前数组是否包含相同的元素,判断的是所有的值,而不是地址,结果是%v", query.Contains(Book{
|
||||||
|
Name: "Go语言",
|
||||||
|
Author: "Go",
|
||||||
|
Money: 100,
|
||||||
|
WordsNum: 1000,
|
||||||
|
PublishTime: time.Date(2020, 1, 1, 10, 0, 0, 0, time.Local),
|
||||||
|
})))
|
||||||
|
}
|
||||||
|
|
||||||
|
func Calculate() {
|
||||||
|
query := linq.From([]int{1, 2, 3, 4, 5, 6, 7, 8, 9})
|
||||||
|
fmt.Println(fmt.Sprintf("平均值为:%f", query.Average()))
|
||||||
|
fmt.Println(fmt.Sprintf("最大的值为%d", query.Max()))
|
||||||
|
fmt.Println(fmt.Sprintf("最小的值为%d", query.Min()))
|
||||||
|
}
|
||||||
|
|
||||||
|
func AnyWith() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
result := query.AnyWith(PublishTimeBeforeFunc) //判断是否有任意个元素满足条件
|
||||||
|
fmt.Println(fmt.Sprintf("是否有任意书的发表时间早于2020年1月1号,答案是%v", result))
|
||||||
|
|
||||||
|
result = query.AnyWith(PublishTimeAfterFunc2) //判断是否有任意个元素满足条件
|
||||||
|
fmt.Println(fmt.Sprintf("是否有任意书的发表时间晚于2021年1月1号,答案是%v", result))
|
||||||
|
}
|
||||||
|
|
||||||
|
func All() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
result := query.All(PublishTimeBeforeFunc)
|
||||||
|
fmt.Println(fmt.Sprintf("是否所有的书的发表时间都早于2020年1月1号,答案是%v", result))
|
||||||
|
|
||||||
|
result = query.All(PublishTimeAfterFunc)
|
||||||
|
fmt.Println(fmt.Sprintf("是否所有的书的发表时间都晚于2018年1月1号,答案是%v", result))
|
||||||
|
}
|
||||||
|
|
||||||
|
func Aggregate() {
|
||||||
|
bookList := MakeBook()
|
||||||
|
query := linq.From(bookList)
|
||||||
|
// 这边的聚合操作其实就是【自定义对应的比较方法】。
|
||||||
|
// 根据注释,第一次拿到的是数组的第一个元素,然后跟第二个元素进行比较,如果第二个元素符合条件则【替换第一个元素】,否则当前聚合操作还是持有第一个元素。
|
||||||
|
// 以此类推后面的元素
|
||||||
|
result := query.Aggregate(AggregateFunc).(Book)
|
||||||
|
fmt.Println(fmt.Sprintf("聚合操作查询出的结果是【%s】这本书,它的发布时间最早为:%v", result.Name, timed.GetTimeDefaultFormatString(result.PublishTime.Unix())))
|
||||||
|
}
|
||||||
@@ -55,6 +55,8 @@ json与struct之间转换处理工具使用示例
|
|||||||
|
|
||||||
2021/02/09:新增merge源码阅读和单测代码
|
2021/02/09:新增merge源码阅读和单测代码
|
||||||
|
|
||||||
|
2021/02/23:新增linq包使用示例
|
||||||
|
|
||||||
# mod vendor模式加载包
|
# mod vendor模式加载包
|
||||||
通过go mod的方式加载的github上面的包会有报红的问题,但是包本身是可以运行的,这样就是会有一个问题,如果你想要点击去看方法的内容,没办法做到
|
通过go mod的方式加载的github上面的包会有报红的问题,但是包本身是可以运行的,这样就是会有一个问题,如果你想要点击去看方法的内容,没办法做到
|
||||||
|
|
||||||
|
|||||||
Reference in New Issue
Block a user