Exemple #1
0
func (c *ClientConn) newEmptyResultset(stmt *sqlparser.Select) *mysql.Resultset {
	r := new(mysql.Resultset)
	r.Fields = make([]*mysql.Field, len(stmt.SelectExprs))

	for i, expr := range stmt.SelectExprs {
		r.Fields[i] = &mysql.Field{}
		switch e := expr.(type) {
		case *sqlparser.StarExpr:
			r.Fields[i].Name = []byte("*")
		case *sqlparser.NonStarExpr:
			if e.As != nil {
				r.Fields[i].Name = e.As
				r.Fields[i].OrgName = hack.Slice(nstring(e.Expr))
			} else {
				r.Fields[i].Name = hack.Slice(nstring(e.Expr))
			}
		default:
			r.Fields[i].Name = hack.Slice(nstring(e))
		}
	}

	r.Values = make([][]interface{}, 0)
	r.RowDatas = make([]mysql.RowData, 0)

	return r
}
//compare value using asc
func cmpValue(v1 interface{}, v2 interface{}) int {
	if v1 == nil && v2 == nil {
		return 0
	} else if v1 == nil {
		return -1
	} else if v2 == nil {
		return 1
	}

	switch v := v1.(type) {
	case string:
		s := v2.(string)
		return bytes.Compare(hack.Slice(v), hack.Slice(s))
	case []byte:
		s := v2.([]byte)
		return bytes.Compare(v, s)
	case int64:
		s := v2.(int64)
		if v < s {
			return -1
		} else if v > s {
			return 1
		} else {
			return 0
		}
	case uint64:
		s := v2.(uint64)
		if v < s {
			return -1
		} else if v > s {
			return 1
		} else {
			return 0
		}
	case float64:
		s := v2.(float64)
		if v < s {
			return -1
		} else if v > s {
			return 1
		} else {
			return 0
		}
	default:
		//can not go here
		panic(fmt.Sprintf("invalid type %T", v))
	}
}
func (c *ClientConn) buildResultset(fields []*mysql.Field, names []string, values [][]interface{}) (*mysql.Resultset, error) {
	var ExistFields bool
	r := new(mysql.Resultset)

	r.Fields = make([]*mysql.Field, len(names))
	//use the field def that get from true database
	if len(fields) != 0 {
		if len(r.Fields) == len(fields) {
			ExistFields = true
		} else {
			return nil, errors.ErrInvalidArgument
		}
	}

	var b []byte
	var err error

	for i, vs := range values {
		if len(vs) != len(r.Fields) {
			return nil, fmt.Errorf("row %d has %d column not equal %d", i, len(vs), len(r.Fields))
		}

		var row []byte
		for j, value := range vs {
			//列的定义
			if i == 0 {
				if ExistFields {
					r.Fields[j] = fields[j]
				} else {
					field := &mysql.Field{}
					r.Fields[j] = field
					field.Name = hack.Slice(names[j])
					if err = formatField(field, value); err != nil {
						return nil, err
					}
				}

			}
			b, err = formatValue(value)
			if err != nil {
				return nil, err
			}

			row = append(row, mysql.PutLengthEncodedString(b)...)
		}

		r.RowDatas = append(r.RowDatas, row)
	}

	return r, nil
}
func formatValue(value interface{}) ([]byte, error) {
	if value == nil {
		return hack.Slice("NULL"), nil
	}
	switch v := value.(type) {
	case int8:
		return strconv.AppendInt(nil, int64(v), 10), nil
	case int16:
		return strconv.AppendInt(nil, int64(v), 10), nil
	case int32:
		return strconv.AppendInt(nil, int64(v), 10), nil
	case int64:
		return strconv.AppendInt(nil, int64(v), 10), nil
	case int:
		return strconv.AppendInt(nil, int64(v), 10), nil
	case uint8:
		return strconv.AppendUint(nil, uint64(v), 10), nil
	case uint16:
		return strconv.AppendUint(nil, uint64(v), 10), nil
	case uint32:
		return strconv.AppendUint(nil, uint64(v), 10), nil
	case uint64:
		return strconv.AppendUint(nil, uint64(v), 10), nil
	case uint:
		return strconv.AppendUint(nil, uint64(v), 10), nil
	case float32:
		return strconv.AppendFloat(nil, float64(v), 'f', -1, 64), nil
	case float64:
		return strconv.AppendFloat(nil, float64(v), 'f', -1, 64), nil
	case []byte:
		return v, nil
	case string:
		return hack.Slice(v), nil
	default:
		return nil, fmt.Errorf("invalid type %T", value)
	}
}