Files
dolthub--doltgresql/server/functions/split_part.go
T
2026-07-13 12:32:25 +08:00

59 lines
1.8 KiB
Go

// Copyright 2024 Dolthub, 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,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package functions
import (
"strings"
"github.com/cockroachdb/errors"
"github.com/dolthub/go-mysql-server/sql"
"github.com/dolthub/doltgresql/server/functions/framework"
pgtypes "github.com/dolthub/doltgresql/server/types"
"github.com/dolthub/doltgresql/utils"
)
// initSplitPart registers the functions to the catalog.
func initSplitPart() {
framework.RegisterFunction(split_part_text_text_int32)
}
// split_part_text_text_int32 represents the PostgreSQL function of the same name, taking the same parameters.
var split_part_text_text_int32 = framework.Function3{
Name: "split_part",
Return: pgtypes.Text,
Parameters: [3]*pgtypes.DoltgresType{pgtypes.Text, pgtypes.Text, pgtypes.Int32},
Strict: true,
Callable: func(ctx *sql.Context, _ [4]*pgtypes.DoltgresType, str any, delimiter any, n any) (any, error) {
if n.(int32) == 0 {
return nil, errors.Errorf("field position must not be zero")
}
var parts []string
if len(delimiter.(string)) > 0 {
parts = strings.Split(str.(string), delimiter.(string))
} else {
parts = []string{str.(string)}
}
if int(utils.Abs(n.(int32))) > len(parts) {
return "", nil
}
if n.(int32) > 0 {
return parts[n.(int32)-1], nil
} else {
return parts[int32(len(parts))+n.(int32)], nil
}
},
}