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// Copyright 2019 The Xorm Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package core
import (
"database/sql"
"errors"
"reflect"
"sync"
)
// Rows represents rows of table
type Rows struct {
*sql.Rows
db *DB
}
// ToMapString returns all records
func (rs *Rows) ToMapString() ([]map[string]string, error) {
cols, err := rs.Columns()
if err != nil {
return nil, err
}
var results = make([]map[string]string, 0, 10)
for rs.Next() {
var record = make(map[string]string, len(cols))
err = rs.ScanMap(&record)
if err != nil {
return nil, err
}
results = append(results, record)
}
return results, nil
}
// ScanStructByIndex scan data to a struct's pointer according field index
func (rs *Rows) ScanStructByIndex(dest ...interface{}) error {
if len(dest) == 0 {
return errors.New("at least one struct")
}
vvvs := make([]reflect.Value, len(dest))
for i, s := range dest {
vv := reflect.ValueOf(s)
if vv.Kind() != reflect.Ptr || vv.Elem().Kind() != reflect.Struct {
return errors.New("dest should be a struct's pointer")
}
vvvs[i] = vv.Elem()
}
cols, err := rs.Columns()
if err != nil {
return err
}
newDest := make([]interface{}, len(cols))
var i = 0
for _, vvv := range vvvs {
for j := 0; j < vvv.NumField(); j++ {
newDest[i] = vvv.Field(j).Addr().Interface()
i = i + 1
}
}
return rs.Rows.Scan(newDest...)
}
var (
fieldCache = make(map[reflect.Type]map[string]int)
fieldCacheMutex sync.RWMutex
)
func fieldByName(v reflect.Value, name string) reflect.Value {
t := v.Type()
fieldCacheMutex.RLock()
cache, ok := fieldCache[t]
fieldCacheMutex.RUnlock()
if !ok {
cache = make(map[string]int)
for i := 0; i < v.NumField(); i++ {
cache[t.Field(i).Name] = i
}
fieldCacheMutex.Lock()
fieldCache[t] = cache
fieldCacheMutex.Unlock()
}
if i, ok := cache[name]; ok {
return v.Field(i)
}
return reflect.Zero(t)
}
// ScanStructByName scan data to a struct's pointer according field name
func (rs *Rows) ScanStructByName(dest interface{}) error {
vv := reflect.ValueOf(dest)
if vv.Kind() != reflect.Ptr || vv.Elem().Kind() != reflect.Struct {
return errors.New("dest should be a struct's pointer")
}
cols, err := rs.Columns()
if err != nil {
return err
}
newDest := make([]interface{}, len(cols))
var v EmptyScanner
for j, name := range cols {
f := fieldByName(vv.Elem(), rs.db.Mapper.Table2Obj(name))
if f.IsValid() {
newDest[j] = f.Addr().Interface()
} else {
newDest[j] = &v
}
}
return rs.Rows.Scan(newDest...)
}
// ScanSlice scan data to a slice's pointer, slice's length should equal to columns' number
func (rs *Rows) ScanSlice(dest interface{}) error {
vv := reflect.ValueOf(dest)
if vv.Kind() != reflect.Ptr || vv.Elem().Kind() != reflect.Slice {
return errors.New("dest should be a slice's pointer")
}
vvv := vv.Elem()
cols, err := rs.Columns()
if err != nil {
return err
}
newDest := make([]interface{}, len(cols))
for j := 0; j < len(cols); j++ {
if j >= vvv.Len() {
newDest[j] = reflect.New(vvv.Type().Elem()).Interface()
} else {
newDest[j] = vvv.Index(j).Addr().Interface()
}
}
err = rs.Rows.Scan(newDest...)
if err != nil {
return err
}
srcLen := vvv.Len()
for i := srcLen; i < len(cols); i++ {
vvv = reflect.Append(vvv, reflect.ValueOf(newDest[i]).Elem())
}
return nil
}
// ScanMap scan data to a map's pointer
func (rs *Rows) ScanMap(dest interface{}) error {
vv := reflect.ValueOf(dest)
if vv.Kind() != reflect.Ptr || vv.Elem().Kind() != reflect.Map {
return errors.New("dest should be a map's pointer")
}
cols, err := rs.Columns()
if err != nil {
return err
}
newDest := make([]interface{}, len(cols))
vvv := vv.Elem()
for i := range cols {
newDest[i] = rs.db.reflectNew(vvv.Type().Elem()).Interface()
}
err = rs.Rows.Scan(newDest...)
if err != nil {
return err
}
for i, name := range cols {
vname := reflect.ValueOf(name)
vvv.SetMapIndex(vname, reflect.ValueOf(newDest[i]).Elem())
}
return nil
}
// Row reprents a row of a tab
type Row struct {
rows *Rows
// One of these two will be non-nil:
err error // deferred error for easy chaining
}
// ErrorRow return an error row
func ErrorRow(err error) *Row {
return &Row{
err: err,
}
}
// NewRow from rows
func NewRow(rows *Rows, err error) *Row {
return &Row{rows, err}
}
// Columns returns all columns of the row
func (row *Row) Columns() ([]string, error) {
if row.err != nil {
return nil, row.err
}
return row.rows.Columns()
}
// Scan retrieves all row column values
func (row *Row) Scan(dest ...interface{}) error {
if row.err != nil {
return row.err
}
defer row.rows.Close()
for _, dp := range dest {
if _, ok := dp.(*sql.RawBytes); ok {
return errors.New("sql: RawBytes isn't allowed on Row.Scan")
}
}
if !row.rows.Next() {
if err := row.rows.Err(); err != nil {
return err
}
return sql.ErrNoRows
}
err := row.rows.Scan(dest...)
if err != nil {
return err
}
// Make sure the query can be processed to completion with no errors.
return row.rows.Close()
}
// ScanStructByName retrieves all row column values into a struct
func (row *Row) ScanStructByName(dest interface{}) error {
if row.err != nil {
return row.err
}
defer row.rows.Close()
if !row.rows.Next() {
if err := row.rows.Err(); err != nil {
return err
}
return sql.ErrNoRows
}
err := row.rows.ScanStructByName(dest)
if err != nil {
return err
}
// Make sure the query can be processed to completion with no errors.
return row.rows.Close()
}
// ScanStructByIndex retrieves all row column values into a struct
func (row *Row) ScanStructByIndex(dest interface{}) error {
if row.err != nil {
return row.err
}
defer row.rows.Close()
if !row.rows.Next() {
if err := row.rows.Err(); err != nil {
return err
}
return sql.ErrNoRows
}
err := row.rows.ScanStructByIndex(dest)
if err != nil {
return err
}
// Make sure the query can be processed to completion with no errors.
return row.rows.Close()
}
// ScanSlice scan data to a slice's pointer, slice's length should equal to columns' number
func (row *Row) ScanSlice(dest interface{}) error {
if row.err != nil {
return row.err
}
defer row.rows.Close()
if !row.rows.Next() {
if err := row.rows.Err(); err != nil {
return err
}
return sql.ErrNoRows
}
err := row.rows.ScanSlice(dest)
if err != nil {
return err
}
// Make sure the query can be processed to completion with no errors.
return row.rows.Close()
}
// ScanMap scan data to a map's pointer
func (row *Row) ScanMap(dest interface{}) error {
if row.err != nil {
return row.err
}
defer row.rows.Close()
if !row.rows.Next() {
if err := row.rows.Err(); err != nil {
return err
}
return sql.ErrNoRows
}
err := row.rows.ScanMap(dest)
if err != nil {
return err
}
// Make sure the query can be processed to completion with no errors.
return row.rows.Close()
}
// ToMapString returns all clumns of this record
func (row *Row) ToMapString() (map[string]string, error) {
cols, err := row.Columns()
if err != nil {
return nil, err
}
var record = make(map[string]string, len(cols))
err = row.ScanMap(&record)
if err != nil {
return nil, err
}
return record, nil
}