GoMybatisRowsDecoder.go

package GoMybatis

import (
	"database/sql"
	"fmt"
	"reflect"
	"strconv"
	"time"
)

func rows2maps(rows *sql.Rows) (resultsSlice []map[string][]byte, err error) {
	fields, err := rows.Columns()
	if err != nil {
		return nil, err
	}
	fieldTypes, err := rows.ColumnTypes()
	if err != nil {
		return nil, err
	}
	for rows.Next() {
		result, err := row2map(rows, fields, fieldTypes)
		if err != nil {
			return nil, err
		}
		resultsSlice = append(resultsSlice, result)
	}
	return resultsSlice, nil
}

func row2map(rows *sql.Rows, fields []string, fieldTypes []*sql.ColumnType) (resultsMap map[string][]byte, err error) {
	result := make(map[string][]byte)
	scanResultContainers := make([]interface{}, len(fields))
	for i := 0; i < len(fields); i++ {
		var scanResultContainer interface{}
		scanResultContainers[i] = &scanResultContainer
	}
	if err := rows.Scan(scanResultContainers...); err != nil {
		return nil, err
	}

	for ii, key := range fields {
		rawValue := reflect.Indirect(reflect.ValueOf(scanResultContainers[ii]))
		//if row is null then ignore
		if rawValue.Interface() == nil {
			result[key] = []byte{}
			continue
		}

		if data, err := value2Bytes(&rawValue, key, fieldTypes[ii]); err == nil {
			result[key] = data
		} else {
			return nil, err // !nashtsai! REVIEW, should return err or just error log?
		}
	}
	return result, nil
}

func value2Bytes(rawValue *reflect.Value, column string, columnType *sql.ColumnType) ([]byte, error) {
	//TODO convert type with column and column type
	str, err := value2String(rawValue)
	if err != nil {
		return nil, err
	}
	return []byte(str), nil
}

func value2String(rawValue *reflect.Value) (str string, err error) {
	aa := reflect.TypeOf((*rawValue).Interface())
	vv := reflect.ValueOf((*rawValue).Interface())
	switch aa.Kind() {
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		str = strconv.FormatInt(vv.Int(), 10)
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		str = strconv.FormatUint(vv.Uint(), 10)
	case reflect.Float32, reflect.Float64:
		str = strconv.FormatFloat(vv.Float(), 'f', -1, 64)
	case reflect.String:
		str = vv.String()
	case reflect.Array, reflect.Slice:
		switch aa.Elem().Kind() {
		case reflect.Uint8:
			data := rawValue.Interface().([]byte)
			str = string(data)
			if str == "\x00" {
				str = "0"
			}
		default:
			err = fmt.Errorf("Unsupported struct type %v", vv.Type().Name())
		}
		// time type
	case reflect.Struct:
		if aa.ConvertibleTo(TimeType) {
			str = vv.Convert(TimeType).Interface().(time.Time).Format(time.RFC3339Nano)
		} else {
			err = fmt.Errorf("Unsupported struct type %v", vv.Type().Name())
		}
	case reflect.Bool:
		str = strconv.FormatBool(vv.Bool())
	case reflect.Complex128, reflect.Complex64:
		str = fmt.Sprintf("%v", vv.Complex())
		/* TODO: unsupported types below
		   case reflect.Map:
		   case reflect.Ptr:
		   case reflect.Uintptr:
		   case reflect.UnsafePointer:
		   case reflect.Chan, reflect.Func, reflect.Interface:
		*/
	default:
		err = fmt.Errorf("Unsupported struct type %v", vv.Type().Name())
	}
	return
}