// ConvertDatumToDecimal converts datum to decimal.
func ConvertDatumToDecimal(d Datum) (mysql.Decimal, error) {
switch d.Kind() {
case KindInt64:
return mysql.NewDecimalFromInt(d.GetInt64(), 0), nil
case KindUint64:
return mysql.NewDecimalFromUint(d.GetUint64(), 0), nil
case KindFloat32:
return mysql.NewDecimalFromFloat(float64(d.GetFloat32())), nil
case KindFloat64:
return mysql.NewDecimalFromFloat(d.GetFloat64()), nil
case KindString:
return mysql.ParseDecimal(d.GetString())
case KindMysqlDecimal:
return d.GetMysqlDecimal(), nil
case KindMysqlHex:
return mysql.NewDecimalFromInt(int64(d.GetMysqlHex().Value), 0), nil
case KindMysqlBit:
return mysql.NewDecimalFromUint(uint64(d.GetMysqlBit().Value), 0), nil
case KindMysqlEnum:
return mysql.NewDecimalFromUint(uint64(d.GetMysqlEnum().Value), 0), nil
case KindMysqlSet:
return mysql.NewDecimalFromUint(uint64(d.GetMysqlSet().Value), 0), nil
default:
return mysql.Decimal{}, fmt.Errorf("can't convert %v to decimal", d.GetValue())
}
}
func builtinAvg(args []interface{}, ctx map[interface{}]interface{}) (v interface{}, err error) {
// avg use decimal for integer and decimal type, use float for others
// see https://dev.mysql.com/doc/refman/5.7/en/group-by-functions.html
type avg struct {
sum interface{}
n uint64
decimalResult bool
}
if _, ok := ctx[ExprEvalArgAggEmpty]; ok {
return
}
fn := ctx[ExprEvalFn]
distinct := getDistinct(ctx, fn)
if _, ok := ctx[ExprAggDone]; ok {
distinct.clear()
data, ok := ctx[fn].(avg)
if !ok {
return
}
switch x := data.sum.(type) {
case nil:
return nil, nil
case float64:
return float64(x) / float64(data.n), nil
case mysql.Decimal:
return x.Div(mysql.NewDecimalFromUint(data.n, 0)), nil
}
panic("should not happend")
}
data, _ := ctx[fn].(avg)
y := args[0]
if types.IsNil(y) {
return
}
ok, err := distinct.isDistinct(args...)
if err != nil || !ok {
// if err or not distinct, return
return nil, err
}
if types.IsNil(data.sum) {
data.n = 0
}
data.sum, err = calculateSum(data.sum, y)
if err != nil {
return nil, errors.Errorf("eval AVG aggregate err: %v", err)
}
data.n++
ctx[fn] = data
return
}
func (e *Evaluator) evalAggAvg(v *ast.AggregateFuncExpr) {
ctx := v.GetContext()
switch x := ctx.Value.(type) {
case float64:
ctx.Value = x / float64(ctx.Count)
case mysql.Decimal:
ctx.Value = x.Div(mysql.NewDecimalFromUint(uint64(ctx.Count), 0))
}
v.SetValue(ctx.Value)
}
func (s *testTypeEtcSuite) TestCoerce(c *check.C) {
checkCoerce(c, uint64(3), int16(4))
checkCoerce(c, uint64(0xffffffffffffffff), float64(2.3))
checkCoerce(c, float64(1.3), uint64(0xffffffffffffffff))
checkCoerce(c, int64(11), float64(4.313))
checkCoerce(c, uint(2), uint16(52))
checkCoerce(c, uint8(8), true)
checkCoerce(c, uint32(62), int8(8))
checkCoerce(c, mysql.NewDecimalFromInt(1, 0), false)
checkCoerce(c, float32(3.4), mysql.NewDecimalFromUint(1, 0))
checkCoerce(c, int32(43), 3.235)
}
// GetGroupResult implements AggregationFunction interface.
func (af *avgFunction) GetGroupResult(groupKey []byte) (d types.Datum) {
ctx := af.getContext(groupKey)
switch ctx.Value.Kind() {
case types.KindFloat64:
t := ctx.Value.GetFloat64() / float64(ctx.Count)
d.SetValue(t)
case types.KindMysqlDecimal:
x := ctx.Value.GetMysqlDecimal()
t := x.Div(mysql.NewDecimalFromUint(uint64(ctx.Count), 0))
d.SetMysqlDecimal(t)
}
return
}
func (e *Evaluator) evalAggAvg(v *ast.AggregateFuncExpr) {
ctx := v.GetContext()
switch ctx.Value.Kind() {
case types.KindFloat64:
t := ctx.Value.GetFloat64() / float64(ctx.Count)
v.SetValue(t)
case types.KindMysqlDecimal:
x := ctx.Value.GetMysqlDecimal()
t := x.Div(mysql.NewDecimalFromUint(uint64(ctx.Count), 0))
v.SetMysqlDecimal(t)
}
ctx.Value = *v.GetDatum()
}
// GetGroupResult implements AggregationFunction interface.
func (af *avgFunction) GetGroupResult(groupKey []byte) (d types.Datum) {
ctx := af.getContext(groupKey)
switch x := ctx.Value.(type) {
case float64:
t := x / float64(ctx.Count)
ctx.Value = t
d.SetFloat64(t)
case mysql.Decimal:
t := x.Div(mysql.NewDecimalFromUint(uint64(ctx.Count), 0))
ctx.Value = t
d.SetMysqlDecimal(t)
}
return
}
func (d *Datum) convertToMysqlDecimal(target *FieldType) (Datum, error) {
var ret Datum
var dec mysql.Decimal
switch d.k {
case KindInt64:
dec = mysql.NewDecimalFromInt(d.GetInt64(), 0)
case KindUint64:
dec = mysql.NewDecimalFromUint(d.GetUint64(), 0)
case KindFloat32, KindFloat64:
dec = mysql.NewDecimalFromFloat(d.GetFloat64())
case KindString, KindBytes:
var err error
dec, err = mysql.ParseDecimal(d.GetString())
if err != nil {
return ret, errors.Trace(err)
}
case KindMysqlDecimal:
dec = d.GetMysqlDecimal()
case KindMysqlTime:
dec = d.GetMysqlTime().ToNumber()
case KindMysqlDuration:
dec = d.GetMysqlDuration().ToNumber()
case KindMysqlBit:
dec = mysql.NewDecimalFromFloat(d.GetMysqlBit().ToNumber())
case KindMysqlEnum:
dec = mysql.NewDecimalFromFloat(d.GetMysqlEnum().ToNumber())
case KindMysqlHex:
dec = mysql.NewDecimalFromFloat(d.GetMysqlHex().ToNumber())
case KindMysqlSet:
dec = mysql.NewDecimalFromFloat(d.GetMysqlSet().ToNumber())
default:
return invalidConv(d, target.Tp)
}
if target.Decimal != UnspecifiedLength {
dec = dec.Round(int32(target.Decimal))
}
ret.SetValue(dec)
return ret, nil
}
