Files
tidb/expression/builtin_json.go

73 lines
2.2 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 (
"github.com/juju/errors"
"github.com/pingcap/tidb/ast"
"github.com/pingcap/tidb/context"
"github.com/pingcap/tidb/mysql"
"github.com/pingcap/tidb/util/types"
"github.com/pingcap/tipb/go-tipb"
)
// jsonFunctionNameToPB is for pushdown json functions to storage engine.
var jsonFunctionNameToPB = map[string]tipb.ExprType{
ast.JSONType: tipb.ExprType_JsonType,
ast.JSONExtract: tipb.ExprType_JsonExtract,
ast.JSONUnquote: tipb.ExprType_JsonUnquote,
ast.JSONValid: tipb.ExprType_JsonValid,
ast.JSONObject: tipb.ExprType_JsonObject,
ast.JSONArray: tipb.ExprType_JsonArray,
ast.JSONMerge: tipb.ExprType_JsonMerge,
ast.JSONSet: tipb.ExprType_JsonSet,
ast.JSONInsert: tipb.ExprType_JsonInsert,
ast.JSONReplace: tipb.ExprType_JsonReplace,
ast.JSONRemove: tipb.ExprType_JsonRemove,
ast.JSONContains: tipb.ExprType_JsonContains,
}
var (
_ functionClass = &jsonTypeFunctionClass{}
)
type jsonTypeFunctionClass struct {
baseFunctionClass
}
type builtinJSONTypeSig struct {
baseBuiltinFunc
}
func (c *jsonTypeFunctionClass) getFunction(args []Expression, ctx context.Context) (builtinFunc, error) {
return &builtinJSONTypeSig{newBaseBuiltinFunc(args, ctx)}, errors.Trace(c.verifyArgs(args))
}
func (b *builtinJSONTypeSig) eval(row []types.Datum) (d types.Datum, err error) {
args, err := b.evalArgs(row)
if err != nil {
return d, errors.Trace(err)
}
sc := b.ctx.GetSessionVars().StmtCtx
if args[0].Kind() != types.KindNull {
var djson types.Datum
djson, err = args[0].ConvertTo(sc, types.NewFieldType(mysql.TypeJSON))
if err == nil {
d.SetString(djson.GetMysqlJSON().Type())
}
}
return d, errors.Trace(err)
}