63 lines
1.7 KiB
Go
63 lines
1.7 KiB
Go
// Copyright 2017 PingCAP, Inc.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package expression
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
)
|
|
|
|
// ExplainInfo implements the Expression interface.
|
|
func (expr *ScalarFunction) ExplainInfo() string {
|
|
buffer := bytes.NewBufferString(fmt.Sprintf("%s(", expr.FuncName.L))
|
|
for i, arg := range expr.GetArgs() {
|
|
buffer.WriteString(fmt.Sprintf("%s", arg.ExplainInfo()))
|
|
if i+1 < len(expr.GetArgs()) {
|
|
buffer.WriteString(", ")
|
|
}
|
|
}
|
|
buffer.WriteString(")")
|
|
return buffer.String()
|
|
}
|
|
|
|
// ExplainInfo implements the Expression interface.
|
|
func (expr *Column) ExplainInfo() string {
|
|
return expr.String()
|
|
}
|
|
|
|
// ExplainInfo implements the Expression interface.
|
|
func (expr *Constant) ExplainInfo() string {
|
|
valStr, err := expr.Value.ToString()
|
|
if err != nil {
|
|
valStr = "not recognized const value"
|
|
}
|
|
return valStr
|
|
}
|
|
|
|
// ExplainAggFunc generates explain information for a aggregation function.
|
|
func ExplainAggFunc(agg AggregationFunction) string {
|
|
buffer := bytes.NewBufferString(fmt.Sprintf("%s(", agg.GetName()))
|
|
if agg.IsDistinct() {
|
|
buffer.WriteString("distinct ")
|
|
}
|
|
for i, arg := range agg.GetArgs() {
|
|
buffer.WriteString(arg.ExplainInfo())
|
|
if i+1 < len(agg.GetArgs()) {
|
|
buffer.WriteString(", ")
|
|
}
|
|
}
|
|
buffer.WriteString(")")
|
|
return buffer.String()
|
|
}
|