Example #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
}
Example #2
0
func (c *ClientConn) limitSelectResult(r *mysql.Resultset, stmt *sqlparser.Select) error {
	if stmt.Limit == nil {
		return nil
	}

	var offset, count int64
	var err error
	if stmt.Limit.Offset == nil {
		offset = 0
	} else {
		if o, ok := stmt.Limit.Offset.(sqlparser.NumVal); !ok {
			return fmt.Errorf("invalid select limit %s", nstring(stmt.Limit))
		} else {
			if offset, err = strconv.ParseInt(hack.String([]byte(o)), 10, 64); err != nil {
				return err
			}
		}
	}

	if o, ok := stmt.Limit.Rowcount.(sqlparser.NumVal); !ok {
		return fmt.Errorf("invalid limit %s", nstring(stmt.Limit))
	} else {
		if count, err = strconv.ParseInt(hack.String([]byte(o)), 10, 64); err != nil {
			return err
		} else if count < 0 {
			return fmt.Errorf("invalid limit %s", nstring(stmt.Limit))
		}
	}
	if offset > int64(len(r.Values)) {
		r.Values = nil
		r.RowDatas = nil
		return nil
	}

	if offset+count > int64(len(r.Values)) {
		count = int64(len(r.Values)) - offset
	}

	r.Values = r.Values[offset : offset+count]
	r.RowDatas = r.RowDatas[offset : offset+count]

	return nil
}
Example #3
0
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)
	}
	//assign the values to the result
	r.Values = values

	return r, nil
}