feat: 新增 ScanRows 接口

README.md

@@ -34,7 +34,7 @@ type TableNamer interface {
 
 
 
-### 示例
+### 批量插入 -- 示例
 
 ```go
 
@@ -52,12 +52,12 @@ func (u *User) SuperTableName() string {
 }
 
 func TestSimpleInsert(t *testing.T) {
-	tdMapping := NewTdMapping()
+	tdMapper := NewMapper()
 	data := []any{
 		&User{Name: "张三", Age: 18},
 		&User{Name: "李四", Age: 20},
 	}
-	insertSql, err := tdMapping.ToInsertSQL(data...)
+	insertSql, err := tdMapper.ToInsertSQL(data...)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -70,6 +70,44 @@ INSERT INTO
 `user_李四` USING `super_user` (`name`) TAGS ('李四') (`age`) VALUES (20) 
 ```
 
+### 查询映射 -- 示例
+
+```go
+func QueryOne(db *sql.DB) (*User,error){
+    tdMapper := NewMapper()
+
+    rows,err:=db.Query("select * from User limit 100")
+    if err!=nil {
+    	return err
+    }
+    def rows.Close()
+
+    var user User
+    if err:=ScanRows(&user,rows);err!=nil {
+    	return err
+    }
+    return &user, nil
+}
+
+// 如果查询结果数量为0，则返回 sql.ErrNoRows
+// var ErrNoRows = errors.New("sql: no rows in result set")
+func QueryAll(db *sql.DB)([]*User, error) {
+    tdMapper := NewMapper()
+    
+    rows,err:=db.Query("select * from User limit 100")
+    if err!=nil {
+    	return err
+    }
+    def rows.Close()
+
+    var users []*User
+    if err:=ScanRows(&users,rows);err!=nil {
+    	return err
+    }
+    return &users, nil
+}
+```
+
 
 
 

insert_build.go

@@ -148,7 +148,7 @@ func formatRowValues(values ...any) string {
 		case nil:
 			formattedValues[i] = "null"
 		case time.Time:
-			formattedValues[i] = fmt.Sprintf("'%s'", v.Format("2006-01-02 15:04:05"))
+			formattedValues[i] = fmt.Sprintf("'%s'", v.Format(time.RFC3339))
 		default:
 			if reflect.TypeOf(val).Kind() == reflect.Ptr && reflect.ValueOf(val).IsNil() {
 				formattedValues[i] = "null"

mapping.go

@@ -1,13 +1,16 @@
 package tdmap
 
 import (
+	"context"
+	"database/sql"
+	"errors"
 	"fmt"
 	"reflect"
 	"strings"
 )
 
-func NewMapping() *TdMapping {
+func NewMapper() *Mapper {
-	return &TdMapping{}
+	return &Mapper{}
 }
 
 // TableNamer 定义了一个获取表名的方法。
@@ -15,20 +18,21 @@ type TableNamer interface {
 	TableName() string
 }
 
-type TdMapping struct {
+type Mapper struct {
-	modelMates Map[string, *StructMate]
+	structMateMap SyncMap[string, *StructMate] // 结构体 元信息缓存 key: struct 的唯一类型名称  value: 元信息
 }
 
-func (b *TdMapping) scanStruct(data ...any) error {
+func (b *Mapper) scanStruct(data ...any) error {
 	for _, datum := range data {
 		if reflect.TypeOf(datum).Kind() != reflect.Ptr {
-			return fmt.Errorf("需要指针类型：%v", reflect.TypeOf(datum))
+			//return fmt.Errorf("需要指针类型：%v", reflect.TypeOf(datum))
+			return fmt.Errorf("need a pointer type: %v", reflect.TypeOf(datum))
 		}
 
 		if mate, err := scan(datum); err != nil {
 			return err
 		} else {
-			b.modelMates.Store(mate.UniqueTypeName, mate)
+			b.structMateMap.Store(mate.UniqueTypeName, mate)
 		}
 	}
 
@@ -38,7 +42,7 @@ func (b *TdMapping) scanStruct(data ...any) error {
 // 提取 struct 内的信息
 // @param data 包含 struct 类型的数据
 // @return 返回一个 map[表名][]*TableRowMateria， 如果超级表名为空，则表示普通表
-func (b *TdMapping) extractStructData(data ...any) (map[string][]*TableRowMateria, error) {
+func (b *Mapper) extractStructData(data ...any) (map[string][]*TableRowMateria, error) {
 	result := make(map[string][]*TableRowMateria)
 
 	for _, item := range data {
@@ -65,7 +69,7 @@ func (b *TdMapping) extractStructData(data ...any) (map[string][]*TableRowMateri
 			}
 		}
 
-		mate, ok := b.modelMates.Load(uniqueTypeName)
+		mate, ok := b.structMateMap.Load(uniqueTypeName)
 		if !ok {
 			return nil, fmt.Errorf("not found struct type: %s", uniqueTypeName)
 		}
@@ -81,9 +85,9 @@ func (b *TdMapping) extractStructData(data ...any) (map[string][]*TableRowMateri
 
 		for _, name := range mate.DBAnnotatedNames {
 			// db tag 名称 -- 数据库列名
-			dbColumn := mate.FiledDBNameCache[name]
+			dbColumn := mate.Filed2DBNameCache[name]
 
-			field := vf.FieldByIndex(mate.FieldIndexCache[name])
+			field := vf.FieldByIndex(mate.Field2IndexCache[name])
 			for field.Kind() == reflect.Ptr {
 				if field.IsNil() {
 					break
@@ -99,8 +103,8 @@ func (b *TdMapping) extractStructData(data ...any) (map[string][]*TableRowMateri
 
 		for _, name := range mate.TaggedFieldNames {
 			// db tag 名称 -- 数据库列名
-			tagColumn := mate.FiledDBNameCache[name]
+			tagColumn := mate.Filed2DBNameCache[name]
-			field := vf.FieldByIndex(mate.FieldIndexCache[name])
+			field := vf.FieldByIndex(mate.Field2IndexCache[name])
 			for field.Kind() == reflect.Ptr {
 				if field.IsNil() {
 					break
@@ -121,7 +125,7 @@ func (b *TdMapping) extractStructData(data ...any) (map[string][]*TableRowMateri
 	return result, nil
 }
 
-func (b *TdMapping) ToInsertSQL(data ...any) (string, error) {
+func (b *Mapper) ToInsertSQL(data ...any) (string, error) {
 	// 扫描 struct 类型数据
 	if err := b.scanStruct(data...); err != nil {
 		return "", fmt.Errorf("failed to scan struct: %w", err)
@@ -171,3 +175,115 @@ func (b *TdMapping) ToInsertSQL(data ...any) (string, error) {
 
 	return buf.String(), nil
 }
+
+// ScanRows 扫描多行数据
+// A Superior Option: Use ScanRowsWithContext instead.
+func (b *Mapper) ScanRows(target any, rows *sql.Rows) error {
+	return b.ScanRowsWithContext(context.Background(), target, rows)
+}
+
+// ScanRowsWithContext 扫描多行数据
+// @param ctx 上下文
+// @param target 结构体的指针 或 slice 指针 结构体需要使用 db 标签注解
+// @param rows 数据库返回的行数据
+// @return 返回错误
+func (b *Mapper) ScanRowsWithContext(ctx context.Context, target any, rows *sql.Rows) error {
+	// 确保rows不为nil
+	if rows == nil {
+		return errors.New("rows cannot be nil")
+	}
+
+	// 获取target的反射类型和值
+	vf := reflect.ValueOf(target)
+
+	// 检查target是否为指针类型
+	if vf.Kind() != reflect.Ptr {
+		return errors.New("target must be a pointer to a struct or a slice of structs")
+	}
+
+	if vf.IsNil() {
+		return errors.New("target is nil, please pass a pointer to a struct or a slice of structs")
+	}
+
+	vf = vf.Elem() //  解引用指针以获取目标值
+
+	switch vf.Kind() {
+	case reflect.Struct:
+		// 提取 struct 内的信息
+		if err := b.scanStruct(target); err != nil {
+			return err
+		}
+		// target是指向单个struct的指针，扫描一行数据
+		if !rows.Next() {
+			return sql.ErrNoRows
+		}
+		return b.scanRow(vf, rows)
+	case reflect.Slice:
+		// target是slice的指针
+		sliceElementType := vf.Type().Elem()
+		if sliceElementType.Kind() != reflect.Ptr || sliceElementType.Elem().Kind() != reflect.Struct {
+			return errors.New("target must be a pointer to a slice of structs")
+		}
+
+		// 提取 slice 中 struct 内的信息
+		if err := b.scanStruct(reflect.New(sliceElementType.Elem()).Interface()); err != nil { // 这里在抛出 不是指针类型
+			return err
+		}
+
+		for rows.Next() {
+			select {
+			case <-ctx.Done():
+				vf.SetLen(0) // 清空 slice
+				return ctx.Err()
+			default:
+			}
+
+			// 创建slice元素的新实例
+			newStruct := reflect.New(sliceElementType.Elem())
+			if err := b.scanRow(newStruct, rows); err != nil {
+				return err
+			}
+
+			// 将新实例添加到slice中
+			vf.Set(reflect.Append(vf, newStruct))
+		}
+
+		if vf.Len() == 0 { // 如果slice为空，返回 sql.ErrNoRows
+			return sql.ErrNoRows
+		}
+		return nil
+	default:
+		return errors.New("target must be a pointer to a struct or a slice of structs")
+	}
+}
+
+// scanRow 用于扫描单行数据到结构体
+func (b *Mapper) scanRow(target reflect.Value, rows *sql.Rows) error {
+	target = reflect.Indirect(target)
+
+	uniqueTypeName := getUniqueTypeName(target.Type())
+	mate, ok := b.structMateMap.Load(uniqueTypeName)
+	if !ok {
+		return fmt.Errorf("not found struct type mate: %s", uniqueTypeName)
+	}
+
+	// 假设我们有一个函数来获取列的值
+	columns, err := rows.Columns()
+	if err != nil {
+		return err
+	}
+
+	// 准备目标结构体的地址
+	dest := make([]interface{}, len(columns))
+	for i, colName := range columns {
+		// 拿到缓存的字段索引
+		if idx, ok := mate.DBName2IndexCache[colName]; ok {
+			dest[i] = target.FieldByIndex(idx).Addr().Interface()
+		} else {
+			return fmt.Errorf("no corresponding field found for column %s", colName)
+		}
+	}
+
+	// 扫描数据
+	return rows.Scan(dest...)
+}

mapping_test.go

@@ -2,6 +2,7 @@ package tdmap
 
 import (
 	"database/sql"
+	"encoding/json"
 	"fmt"
 	"testing"
 	"time"
@@ -49,50 +50,26 @@ func (s *TaosUser) TableName() string {
 }
 
 func TestBuilderInsert(t *testing.T) {
-	tdMapping := NewMapping()
+	tdMapper := NewMapper()
 	p := 1
 	data := []any{
 		&TaosDevice{
-			TaosTAG: &TaosTAG{
+			TaosTAG: &TaosTAG{DevId: "设备ID", DevType: "测试设备", DataType: "测试数据"},
-				DevId:    "设备ID",
+			Ts:      time.Now(), LoadUnitId: "负载单体ID", PInt: &p, NullInt32: sql.NullInt32{Int32: 32, Valid: true},
-				DevType:  "测试设备",
-				DataType: "测试数据",
-			},
-			Ts:         time.Now(),
-			LoadUnitId: "负载单体ID",
-			PInt:       &p,
-			NullInt32:  sql.NullInt32{Int32: 32, Valid: true},
 		},
 		&TaosUser{
-			TaosTAG: &TaosTAG{
+			TaosTAG: &TaosTAG{DevId: "User001", DevType: "User类型", DataType: "User数据类型001"},
-				DevId:    "User001",
+			Ts:      time.Now(), Name: "张三",
-				DevType:  "User类型",
-				DataType: "User数据类型001",
-			},
-			Ts:   time.Now(),
-			Name: "张三",
 		}, &TaosUser{
-			TaosTAG: &TaosTAG{
+			TaosTAG: &TaosTAG{DevId: "User002", DevType: "User类型", DataType: "User数据类型002"},
-				DevId:    "User002",
+			Ts:      time.Now(), Name: "李四", Weight: 110,
-				DevType:  "User类型",
-				DataType: "User数据类型002",
-			},
-			Ts:     time.Now(),
-			Name:   "李四",
-			Weight: 110,
 		}, &TaosUser{
-			TaosTAG: &TaosTAG{
+			TaosTAG: &TaosTAG{DevId: "User002", DevType: "User类型", DataType: "User数据类型002"},
-				DevId:    "User002",
+			Name:    "李四", Ts: time.Now(), Weight: 100,
-				DevType:  "User类型",
-				DataType: "User数据类型002",
-			},
-			Name:   "李四",
-			Ts:     time.Now(),
-			Weight: 100,
 		},
 	}
 
-	insertSql, err := tdMapping.ToInsertSQL(data...)
+	insertSql, err := tdMapper.ToInsertSQL(data...)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -113,14 +90,108 @@ func (u *User) SuperTableName() string {
 }
 
 func TestSimpleInsert(t *testing.T) {
-	tdMapping := NewMapping()
+	tdMapper := NewMapper()
 	data := []any{
 		&User{Name: "张三", Age: 18},
 		&User{Name: "李四", Age: 20},
 	}
-	insertSql, err := tdMapping.ToInsertSQL(data...)
+
+	insertSql, err := tdMapper.ToInsertSQL(data...)
 	if err != nil {
 		t.Fatal(err)
 	}
 	fmt.Println(insertSql)
 }
+
+type SuperDevTAG struct {
+	DevId   string `db:"dev_id" taos:"tag"`
+	DevType string `db:"dev_type" taos:"tag"`
+}
+
+type SuperDev struct {
+	SuperDevTAG
+	Ts    time.Time `db:"ts"` // 时间戳
+	AppSn string    `db:"app_sn"`
+	Ct    float64   `db:"ct"`
+}
+
+func (s *SuperDev) SuperTableName() string {
+	return "super_dev"
+}
+func (s *SuperDev) TableName() string {
+	return "dev_" + s.DevId
+}
+
+func TestSuperDevInsert(t *testing.T) {
+	var data = []any{
+		&SuperDev{
+			SuperDevTAG: SuperDevTAG{DevId: "SN001", DevType: "模拟设备"},
+			Ts:          time.Now(), AppSn: "a0001", Ct: 1.0,
+		},
+		&SuperDev{
+			SuperDevTAG: SuperDevTAG{DevId: "SN001", DevType: "模拟设备"},
+			Ts:          time.Now().Add(time.Second), AppSn: "a0002", Ct: 2.0,
+		},
+		&SuperDev{
+			SuperDevTAG: SuperDevTAG{DevId: "SN002", DevType: "模拟设备"},
+			Ts:          time.Now(), AppSn: "a0003", Ct: 3.0,
+		},
+	}
+
+	tdMapper := NewMapper()
+	insertSql, err := tdMapper.ToInsertSQL(data...)
+	if err != nil {
+		t.Fatal(err)
+	}
+	fmt.Println(insertSql)
+}
+
+func TestScanRows(t *testing.T) {
+	/*
+			文档参考： https://docs.taosdata.com/reference/connector/go/#websocket-%E8%BF%9E%E6%8E%A5
+
+			go get github.com/taosdata/driver-go/v3
+
+			import _ "github.com/taosdata/driver-go/v3/taosWS"
+
+			超级表创建
+			CREATE STABLE `super_dev` (`ts` TIMESTAMP , `app_sn` VARCHAR(500) , `ct` INT ) TAGS (`dev_id` VARCHAR(50), `dev_type` VARCHAR(50))
+
+		 	批量插入
+			INSERT INTO
+			`dev_SN001` USING `super_dev` (`dev_id`,`dev_type`) TAGS ('SN001','模拟设备') (`ts`,`app_sn`,`ct`)
+				VALUES ('2024-09-18T16:22:17+08:00','a0001',1),('2024-09-18T16:22:18+08:00','a0002',2)
+			`dev_SN002` USING `super_dev` (`dev_id`,`dev_type`) TAGS ('SN002','模拟设备') (`ts`,`app_sn`,`ct`)
+				VALUES ('2024-09-18T16:22:17+08:00','a0003',3)
+
+	*/
+
+	var taosUri = "root:taosdata@localhost:6041/test"
+	db, err := sql.Open("taosWS", taosUri)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	rows, err := db.Query("select * from super_dev order by ts desc limit 100")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = rows.Close() }()
+
+	tdMapper := NewMapper()
+
+	var sd SuperDev
+	if err = tdMapper.ScanRows(&sd, rows); err != nil {
+		t.Fatal(err)
+	}
+
+	indent, _ := json.MarshalIndent(&sd, "", "  ")
+	fmt.Println(string(indent))
+
+	//var sdArray []SuperDev
+	//if err = tdMapper.ScanRows(&sdArray, rows); err != nil {
+	//	t.Fatal(err)
+	//}
+	//marshal, _ := json.MarshalIndent(sdArray, "", "  ")
+	//fmt.Println(len(sdArray), string(marshal))
+}

scan.go

@@ -20,8 +20,9 @@ func scan(data interface{}) (*StructMate, error) {
 	// 初始化结果结构体
 	sr := StructMate{
 		UniqueTypeName:    uniqueTypeName,
-		FieldIndexCache:  make(map[string][]int, t.NumField()),
+		DBName2IndexCache: make(map[string][]int, t.NumField()),
-		FiledDBNameCache: make(map[string]string, t.NumField()),
+		Field2IndexCache:  make(map[string][]int, t.NumField()),
+		Filed2DBNameCache: make(map[string]string, t.NumField()),
 		DBAnnotatedNames:  make([]string, 0, t.NumField()),
 		TaggedFieldNames:  make([]string, 0, t.NumField()),
 		SuperTableName:    "",
@@ -55,52 +56,34 @@ func scan(data interface{}) (*StructMate, error) {
 				return nil, err
 			}
 
-			for k, v := range subResult.FieldIndexCache {
+			for k, v := range subResult.DBName2IndexCache {
-				sr.FieldIndexCache[k] = append(sr.FieldIndexCache[k], i)
+				sr.DBName2IndexCache[k] = append(sr.DBName2IndexCache[k], i)
-				sr.FieldIndexCache[k] = append(sr.FieldIndexCache[k], v...)
+				sr.DBName2IndexCache[k] = append(sr.DBName2IndexCache[k], v...)
 			}
-			for k, v := range subResult.FiledDBNameCache {
+
-				sr.FiledDBNameCache[k] = v
+			for k, v := range subResult.Field2IndexCache {
+				sr.Field2IndexCache[k] = append(sr.Field2IndexCache[k], i)
+				sr.Field2IndexCache[k] = append(sr.Field2IndexCache[k], v...)
 			}
+			for k, v := range subResult.Filed2DBNameCache {
+				sr.Filed2DBNameCache[k] = v
+			}
+
 			sr.DBAnnotatedNames = append(sr.DBAnnotatedNames, subResult.DBAnnotatedNames...)
 			sr.TaggedFieldNames = append(sr.TaggedFieldNames, subResult.TaggedFieldNames...)
 
 			continue
 		}
 
-		//// 如果字段是结构体或结构体指针，递归处理
-		//if (field.Type.Kind() == reflect.Struct || field.Type.Kind() == reflect.Ptr) && field.Type != timeType {
-		//
-		//	if field.Type.Kind() == reflect.Ptr {
-		//		if fieldValue.IsNil() {
-		//			// 如果指针是 nil，创建一个该类型的零值实例
-		//			zeroValue := reflect.Zero(field.Type.Elem())
-		//			fieldValue = zeroValue
-		//		} else {
-		//			fieldValue = fieldValue.Elem()
-		//		}
-		//	}
-		//
-		//	if !fieldValue.CanInterface() {
-		//		continue
-		//	}
-		//
-		//	subResult, err := scan(fieldValue.Interface())
-		//	if err != nil {
-		//		return nil, err
-		//	}
-		//	sr.merge(subResult)
-		//	continue
-		//}
-
 		// 检查字段是否有db注解
 		columnName := field.Tag.Get("db")
 		if columnName == "-" || columnName == "" {
 			continue
 		}
 
-		sr.FieldIndexCache[field.Name] = []int{i}
+		sr.Field2IndexCache[field.Name] = append(sr.Field2IndexCache[field.Name], i)
-		sr.FiledDBNameCache[field.Name] = columnName
+		sr.DBName2IndexCache[columnName] = append(sr.DBName2IndexCache[columnName], i)
+		sr.Filed2DBNameCache[field.Name] = columnName
 
 		// 检查字段是否有taos注解
 		if field.Tag.Get("taos") == "tag" {
@@ -122,7 +105,7 @@ func getUniqueTypeName(t reflect.Type) string {
 	return uniqueTypeName
 }
 
-func getReflectTypeAndValue(data interface{}) (reflect.Type, reflect.Value) {
+func getReflectTypeAndValue(data any) (reflect.Type, reflect.Value) {
 	t := reflect.TypeOf(data)
 	v := reflect.ValueOf(data)
 

sync_map.go

@@ -4,16 +4,16 @@ import (
 	"sync"
 )
 
-type Map[T any, V any] struct {
+type SyncMap[T any, V any] struct {
 	sMap sync.Map
 }
 
-func (m *Map[T, V]) Store(key T, value V) {
+func (m *SyncMap[T, V]) Store(key T, value V) {
 	m.sMap.Store(key, value)
 
 }
 
-func (m *Map[T, V]) Load(key T) (value V, ok bool) {
+func (m *SyncMap[T, V]) Load(key T) (value V, ok bool) {
 	v, ok := m.sMap.Load(key)
 	if ok {
 		return v.(V), ok
@@ -21,17 +21,17 @@ func (m *Map[T, V]) Load(key T) (value V, ok bool) {
 	return
 }
 
-func (m *Map[T, V]) Delete(key T) {
+func (m *SyncMap[T, V]) Delete(key T) {
 	m.sMap.Delete(key)
 }
 
-func (m *Map[T, V]) Range(f func(T, V) bool) {
+func (m *SyncMap[T, V]) Range(f func(T, V) bool) {
 	m.sMap.Range(func(key, value any) bool {
 		return f(key.(T), value.(V))
 	})
 }
 
-func (m *Map[T, V]) LoadOrStore(key T, value V) (actual V, loaded bool) {
+func (m *SyncMap[T, V]) LoadOrStore(key T, value V) (actual V, loaded bool) {
 	_actual, loaded := m.sMap.LoadOrStore(key, value)
 	if loaded {
 		actual = _actual.(V)

sync_map_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 func TestAA(t *testing.T) {
-	var m Map[string, int]
+	var m SyncMap[string, int]
 	m.Store("a", 1234)
 
 	value, _ := m.Load("a")

types.go

@@ -15,8 +15,9 @@ type TableRowMateria struct {
 type StructMate struct {
 	UniqueTypeName string // 结构体的唯一标识符
 
-	FieldIndexCache  map[string][]int  // 字段名到索引的映射缓存
+	DBName2IndexCache map[string][]int  // db 注解的名称到索引的映射缓存
-	FiledDBNameCache map[string]string // 字段名到 db 注解的名称的映射缓存
+	Field2IndexCache  map[string][]int  // 字段名到索引的映射缓存
+	Filed2DBNameCache map[string]string // 字段名到 db 注解的名称的映射缓存
 
 	DBAnnotatedNames []string // 包含 db 注解的 属性的名称
 	TaggedFieldNames []string // 包含的 tag 注解的 属性的名称