f5/dataset.go

package f5

import (
	"database/sql"
	"q5"
	"reflect"
	"errors"
)

type DataSet struct {
	columns []string
	rows  [][]interface{}
	currRow  []interface{}
	numOfReaded int64
	closed bool
}

//已读取函数(调用Next成功的次数)
func (this *DataSet) NumOfReaded() int64 {
	return this.numOfReaded
}

func (this *DataSet) close() {
	this.closed = true
}

func (this *DataSet) init(rows *sql.Rows) {
	if rows == nil {
		return
	}
	defer rows.Close()

	if len(this.columns) <= 0 {
		columns, err := rows.Columns()
		if err == nil {
			this.columns = columns
		} else {
			panic("NewDataSet Next Columns error:" + err.Error())
		}
	}

	q5.NewSlice(&this.rows, 0, 100)
	for rows.Next() {
		values := []interface{}{}
		for i := 0; i < len(this.columns); i++ {
			str := sql.NullString{}
			values = append(values, &str)
		}
		err := rows.Scan(values...)
		if err != nil {
			panic("NewDataSet Next Scan error:" + err.Error())
		}
		q5.AppendSlice(&this.rows, values)
	}
}

func (this *DataSet) Next() bool {
	/*
	if this.closed {
		panic("NewDataSet is closed")
	}*/
	if this.numOfReaded >= int64(len(this.rows)) {
		return false
	}
	this.currRow = this.rows[this.numOfReaded]
	this.numOfReaded += 1
	return true
}

func (this *DataSet) GetColumns() []string {
	return this.columns
}

/*
   安全版:nil值视为""
*/
func (this *DataSet) GetValues() *[]string {
	values := []string{}
	for _, val := range this.currRow {
		raw_val := val.(*sql.NullString)
		if raw_val.Valid {
			values = append(values, raw_val.String)
		} else {
			values = append(values, *q5.NewEmptyStrPtr())
		}
	}
	return &values
}

/*
   安全版:nil值视为""
*/
func (this *DataSet) GetByName(name string) string {
	val := this.GetRawValueByName(name)
	if val == nil {
		return ""
	} else {
		return *val
	}
}

/*
   安全版:nil值视为""
*/
func (this *DataSet) GetByIndex(index int32) string {
	val := this.GetRawValueByIndex(index)
	if val == nil {
		return ""
	} else {
		return *val
	}
}

/*
   !!!原始版: 调用方应处理值为nil的情况
*/
func (this *DataSet) GetRawValues() *[]string {
	values := []*string{}
	for _, val := range this.currRow {
		raw_val := val.(*sql.NullString)
		if raw_val.Valid {
			values = append(values, &raw_val.String)
		} else {
			values = append(values, nil)
		}
	}
	return nil
}

/*
   !!!原始版: 调用方应处理值为nil的情况
*/
func (this *DataSet) GetRawValueByName(name string) *string {
	this.GetColumns()
	for i := 0; i < len(this.columns); i++ {
		if this.columns[i] == name {
			return this.GetRawValueByIndex(int32(i))
		}
	}
	return nil
}

/*
   !!!原始版: 调用方应处理值为nil的情况
*/
func (this *DataSet) GetRawValueByIndex(index int32) *string {
	this.GetColumns()
	sql_val := this.currRow[index].(*sql.NullString)
	if sql_val.Valid {
		return &sql_val.String
	} else {
		return nil
	}
}

func UnmarshalModelList[T any](ds *DataSet, models *[]*T) error {
	var resultErr error
	for ds.Next() {
		p := new(T)
		resultErr = UnmarshalModel(ds, p)
		if resultErr != nil {
			*models = (*models)[:0]
			break
		}
		q5.AppendSlice(models, p)
	}
	return resultErr
}

/*
   只支持1级指针
 */
func UnmarshalModel[T any](ds *DataSet, m *T) error {
	mType := reflect.TypeOf(m).Elem()
	mVal := reflect.ValueOf(m).Elem()
	for i := 0; i < mType.NumField(); i++ {
		field := mType.Field(i)
		gormTag := field.Tag.Get("gorm")
		if gormTag == "" {
			continue
		}
		gormFieldName := ""
		gormIsJson := false
		params := q5.StrSplit(gormTag, ";")
		for _, val := range params {
			tmpStrs := q5.StrSplit(val, ":")
			if len(tmpStrs) == 2 {
				if tmpStrs[0] == "column" {
					gormFieldName = tmpStrs[1]
				}
				if tmpStrs[0] == "serializer" {
					gormIsJson = true
					if tmpStrs[1] != "json" {
						return errors.New("gorm unknow serializer:" + tmpStrs[1])
					}
				}
			}
		}
		if gormFieldName == "" {
			return errors.New("gormFieldName is empty")
		}
		fieldVal := ds.GetByName(gormFieldName)
		if gormIsJson {
			q5.DecodeJson(fieldVal, mVal.Field(i).Addr().Interface())
		} else {
			if (q5.IsSimpleReflectKind(field.Type.Kind())) {
				mVal.Field(i).Set(*q5.StrToSimpleReflectValue(fieldVal, field.Type.Kind()))
			} else {
				switch field.Type.Kind() {
				case reflect.Ptr:
					{
						if (q5.IsSimpleReflectKind(field.Type.Elem().Kind())) {
							mVal.Field(i).Set(*q5.StrToSimplePtrReflectValue(fieldVal, field.Type.Elem().Kind()))
						} else {
							GetSysLog().Info("UnmarshalModel unknow fieldPtrType:%s", field.Type.Elem());
						}
					}
				default:
					{
						GetSysLog().Info("UnmarshalModel unknow fieldType:%s", field.Type.Kind());
					}
				}
			}
		}
	}
	return nil
}

func newDataSet(rows *sql.Rows) *DataSet {
	dataSet := new(DataSet)
	dataSet.init(rows)
	return dataSet
}