func (v *typeInferrer) aggregateFunc(x *ast.AggregateFuncExpr) {
name := strings.ToLower(x.F)
switch name {
case "count":
ft := types.NewFieldType(mysql.TypeLonglong)
ft.Flen = 21
x.SetType(ft)
}
}
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 (e *Evaluator) aggregateFunc(v *ast.AggregateFuncExpr) bool {
idx := e.aggregateMap[v]
aggr := e.aggregators[idx]
if e.aggregateDone {
v.SetValue(aggr.Output())
return true
}
// TODO: currently only single argument aggregate functions are supported.
e.err = aggr.Input(v.Args[0].GetValue())
return e.err == nil
}
func (v *typeInferrer) aggregateFunc(x *ast.AggregateFuncExpr) {
name := strings.ToLower(x.F)
switch name {
case ast.AggFuncCount:
ft := types.NewFieldType(mysql.TypeLonglong)
ft.Flen = 21
ft.Charset = charset.CharsetBin
ft.Collate = charset.CollationBin
x.SetType(ft)
case ast.AggFuncMax, ast.AggFuncMin:
x.SetType(x.Args[0].GetType())
case ast.AggFuncSum, ast.AggFuncAvg:
ft := types.NewFieldType(mysql.TypeNewDecimal)
ft.Charset = charset.CharsetBin
ft.Collate = charset.CollationBin
x.SetType(ft)
case ast.AggFuncGroupConcat:
ft := types.NewFieldType(mysql.TypeVarString)
ft.Charset = v.defaultCharset
cln, err := charset.GetDefaultCollation(v.defaultCharset)
if err != nil {
v.err = err
}
ft.Collate = cln
x.SetType(ft)
}
}
func (v *typeInferrer) aggregateFunc(x *ast.AggregateFuncExpr) {
name := strings.ToLower(x.F)
switch name {
case "count":
ft := types.NewFieldType(mysql.TypeLonglong)
ft.Flen = 21
ft.Charset = charset.CharsetBin
ft.Collate = charset.CollationBin
x.SetType(ft)
case "sum":
ft := types.NewFieldType(mysql.TypeNewDecimal)
ft.Charset = charset.CharsetBin
ft.Collate = charset.CollationBin
x.SetType(ft)
}
}
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()
}
func (e *Evaluator) evalAggGroupConcat(v *ast.AggregateFuncExpr) {
ctx := v.GetContext()
if ctx.Buffer != nil {
v.SetString(ctx.Buffer.String())
} else {
v.SetNull()
}
}
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()
var y, to mysql.MyDecimal
y.FromUint(uint64(ctx.Count))
mysql.DecimalDiv(x, &y, &to, mysql.DivFracIncr)
to.Round(&to, ctx.Value.Frac()+mysql.DivFracIncr)
v.SetMysqlDecimal(&to)
}
ctx.Value = *v.GetDatum()
}
func (e *Evaluator) evalAggSetValue(v *ast.AggregateFuncExpr) {
ctx := v.GetContext()
v.SetDatum(ctx.Value)
}
func (e *Evaluator) evalAggCount(v *ast.AggregateFuncExpr) {
ctx := v.GetContext()
v.SetInt64(ctx.Count)
}
func (e *Evaluator) evalAggFirstRow(v *ast.AggregateFuncExpr) {
ctx := v.GetContext()
v.SetValue(ctx.Value)
}
