tidb eval_type 代码
文件路径：/parser/types/eval_type.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 types
/ EvalType indicates the specified types that arguments and result of a built-in function should be.
type EvalType byte
const (
/ ETInt represents type INT in evaluation.
ETInt EvalType = iota
/ ETReal represents type REAL in evaluation.
ETReal
/ ETDecimal represents type DECIMAL in evaluation.
ETDecimal
/ ETString represents type STRING in evaluation.
ETString
/ ETDatetime represents type DATETIME in evaluation.
ETDatetime
/ ETTimestamp represents type TIMESTAMP in evaluation.
ETTimestamp
/ ETDuration represents type DURATION in evaluation.
ETDuration
/ ETJson represents type JSON in evaluation.
ETJson
)
/ IsStringKind returns true for ETString, ETDatetime, ETTimestamp, ETDuration, ETJson EvalTypes.
func (et EvalType) IsStringKind() bool {
return et == ETString || et == ETDatetime ||
et == ETTimestamp || et == ETDuration || et == ETJson
}