Scan Rows into struct, fix #59

This commit is contained in:
Jinzhu 2016-02-14 23:29:06 +08:00
parent a7097106b1
commit 6546ec3b5e
5 changed files with 261 additions and 205 deletions

157
README.md
View File

@ -68,15 +68,15 @@ go get -u github.com/jinzhu/gorm
- [Limit](#limit)
- [Offset](#offset)
- [Count](#count)
- [Pluck](#pluck)
- [Raw SQL](#raw-sql)
- [Row & Rows](#row--rows)
- [Scan](#scan)
- [Group & Having](#group--having)
- [Joins](#joins)
- [Transactions](#transactions)
- [Scopes](#scopes)
- [Callbacks](#callbacks)
- [Pluck](#pluck)
- [Scan](#scan)
- [Raw SQL](#raw-sql)
- [Row & Rows](#row--rows)
- [Specifying The Table Name](#specifying-the-table-name)
- [Error Handling](#error-handling)
- [Logger](#logger)
@ -866,73 +866,6 @@ db.Table("deleted_users").Count(&count)
//// SELECT count(*) FROM deleted_users;
```
## Pluck
Get selected attributes as map
```go
var ages []int64
db.Find(&users).Pluck("age", &ages)
var names []string
db.Model(&User{}).Pluck("name", &names)
db.Table("deleted_users").Pluck("name", &names)
// Requesting more than one column? Do it like this:
db.Select("name, age").Find(&users)
```
## Raw SQL
```go
db.Exec("DROP TABLE users;")
db.Exec("UPDATE orders SET shipped_at=? WHERE id IN (?)", time.Now, []int64{11,22,33})
```
## Row & Rows
It is even possible to get query result as `*sql.Row` or `*sql.Rows`
```go
row := db.Table("users").Where("name = ?", "jinzhu").Select("name, age").Row() // (*sql.Row)
row.Scan(&name, &age)
rows, err := db.Model(User{}).Where("name = ?", "jinzhu").Select("name, age, email").Rows() // (*sql.Rows, error)
defer rows.Close()
for rows.Next() {
...
rows.Scan(&name, &age, &email)
...
}
// Raw SQL
rows, err := db.Raw("select name, age, email from users where name = ?", "jinzhu").Rows() // (*sql.Rows, error)
defer rows.Close()
for rows.Next() {
...
rows.Scan(&name, &age, &email)
...
}
```
## Scan
Scan results into another struct.
```go
type Result struct {
Name string
Age int
}
var result Result
db.Table("users").Select("name, age").Where("name = ?", 3).Scan(&result)
// Raw SQL
db.Raw("SELECT name, age FROM users WHERE name = ?", 3).Scan(&result)
```
## Group & Having
```go
@ -1108,7 +1041,7 @@ func (u *User) AfterCreate() (err error) {
}
```
Save/delete operations in gorm are running in a transaction.
Save/delete operations in gorm are running in a transaction.
Changes made in that transaction are not visible unless it is commited.
So if you want to use those changes in your callbacks, you need to run your SQL in the same transaction.
For this Gorm supports passing transactions to callbacks like this:
@ -1120,6 +1053,86 @@ func (u *User) AfterCreate(tx *gorm.DB) (err error) {
}
```
## Pluck
Get selected attributes as map
```go
var ages []int64
db.Find(&users).Pluck("age", &ages)
var names []string
db.Model(&User{}).Pluck("name", &names)
db.Table("deleted_users").Pluck("name", &names)
// Requesting more than one column? Do it like this:
db.Select("name, age").Find(&users)
```
## Scan
Scan results into another struct.
```go
type Result struct {
Name string
Age int
}
var result Result
db.Table("users").Select("name, age").Where("name = ?", 3).Scan(&result)
// Raw SQL
db.Raw("SELECT name, age FROM users WHERE name = ?", 3).Scan(&result)
```
## Raw SQL
```go
db.Exec("DROP TABLE users;")
db.Exec("UPDATE orders SET shipped_at=? WHERE id IN (?)", time.Now, []int64{11,22,33})
```
## Row & Rows
It is even possible to get query result as `*sql.Row` or `*sql.Rows`
```go
row := db.Table("users").Where("name = ?", "jinzhu").Select("name, age").Row() // (*sql.Row)
row.Scan(&name, &age)
rows, err := db.Model(&User{}).Where("name = ?", "jinzhu").Select("name, age, email").Rows() // (*sql.Rows, error)
defer rows.Close()
for rows.Next() {
...
rows.Scan(&name, &age, &email)
...
}
// Raw SQL
rows, err := db.Raw("select name, age, email from users where name = ?", "jinzhu").Rows() // (*sql.Rows, error)
defer rows.Close()
for rows.Next() {
...
rows.Scan(&name, &age, &email)
...
}
```
### Scan Rows
```go
rows, err := db.Model(&User{}).Where("name = ?", "jinzhu").Select("name, age, email").Rows() // (*sql.Rows, error)
defer rows.Close()
for rows.Next() {
var user User
db.ScanRows(rows, &user)
// do something
}
```
## Specifying The Table Name
```go

14
main.go
View File

@ -224,6 +224,20 @@ func (s *DB) Rows() (*sql.Rows, error) {
return s.NewScope(s.Value).rows()
}
func (s *DB) ScanRows(rows *sql.Rows, value interface{}) error {
var (
clone = s.clone()
scope = clone.NewScope(value)
columns, err = rows.Columns()
)
if clone.AddError(err) == nil {
scope.scan(rows, columns, scope.Fields())
}
return clone.Error
}
func (s *DB) Pluck(column string, value interface{}) *DB {
return s.NewScope(s.Value).pluck(column, value).db
}

View File

@ -4,6 +4,7 @@ import (
"database/sql"
"database/sql/driver"
"fmt"
"reflect"
"strconv"
_ "github.com/denisenkom/go-mssqldb"
@ -376,7 +377,7 @@ func TestRows(t *testing.T) {
rows, err := DB.Table("users").Where("name = ? or name = ?", user2.Name, user3.Name).Select("name, age").Rows()
if err != nil {
t.Errorf("Not error should happen, but got")
t.Errorf("Not error should happen, got %v", err)
}
count := 0
@ -386,8 +387,39 @@ func TestRows(t *testing.T) {
rows.Scan(&name, &age)
count++
}
if count != 2 {
t.Errorf("Should found two records with name 3")
t.Errorf("Should found two records")
}
}
func TestScanRows(t *testing.T) {
user1 := User{Name: "ScanRowsUser1", Age: 1, Birthday: now.MustParse("2000-1-1")}
user2 := User{Name: "ScanRowsUser2", Age: 10, Birthday: now.MustParse("2010-1-1")}
user3 := User{Name: "ScanRowsUser3", Age: 20, Birthday: now.MustParse("2020-1-1")}
DB.Save(&user1).Save(&user2).Save(&user3)
rows, err := DB.Table("users").Where("name = ? or name = ?", user2.Name, user3.Name).Select("name, age").Rows()
if err != nil {
t.Errorf("Not error should happen, got %v", err)
}
type Result struct {
Name string
Age int
}
var results []Result
for rows.Next() {
var result Result
if err := DB.ScanRows(rows, &result); err != nil {
t.Errorf("should get no error, but got %v", err)
}
results = append(results, result)
}
if !reflect.DeepEqual(results, []Result{{Name: "ScanRowsUser2", Age: 10}, {Name: "ScanRowsUser3", Age: 20}}) {
t.Errorf("Should find expected results")
}
}

128
utils.go
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@ -2,8 +2,11 @@ package gorm
import (
"bytes"
"database/sql/driver"
"fmt"
"reflect"
"regexp"
"runtime"
"strings"
"sync"
)
@ -50,6 +53,7 @@ const (
upper strCase = true
)
// ToDBName convert string to db name
func ToDBName(name string) string {
if v := smap.Get(name); v != "" {
return v
@ -94,11 +98,14 @@ func ToDBName(name string) string {
return s
}
// SQL expression
type expr struct {
expr string
args []interface{}
}
// Expr generate raw SQL expression for SQL, for example:
// DB.Model(&product).Update("price", gorm.Expr("price * ? + ?", 2, 100))
func Expr(expression string, args ...interface{}) *expr {
return &expr{expr: expression, args: args}
}
@ -148,3 +155,124 @@ func toQueryValues(values [][]interface{}) (results []interface{}) {
}
return
}
func fileWithLineNum() string {
for i := 2; i < 15; i++ {
_, file, line, ok := runtime.Caller(i)
if ok && (!regexp.MustCompile(`jinzhu/gorm/.*.go`).MatchString(file) || regexp.MustCompile(`jinzhu/gorm/.*test.go`).MatchString(file)) {
return fmt.Sprintf("%v:%v", file, line)
}
}
return ""
}
func isBlank(value reflect.Value) bool {
return reflect.DeepEqual(value.Interface(), reflect.Zero(value.Type()).Interface())
}
func toSearchableMap(attrs ...interface{}) (result interface{}) {
if len(attrs) > 1 {
if str, ok := attrs[0].(string); ok {
result = map[string]interface{}{str: attrs[1]}
}
} else if len(attrs) == 1 {
if attr, ok := attrs[0].(map[string]interface{}); ok {
result = attr
}
if attr, ok := attrs[0].(interface{}); ok {
result = attr
}
}
return
}
func convertInterfaceToMap(values interface{}) map[string]interface{} {
attrs := map[string]interface{}{}
switch value := values.(type) {
case map[string]interface{}:
for k, v := range value {
attrs[k] = v
}
case []interface{}:
for _, v := range value {
for key, value := range convertInterfaceToMap(v) {
attrs[key] = value
}
}
case interface{}:
reflectValue := reflect.ValueOf(values)
switch reflectValue.Kind() {
case reflect.Map:
for _, key := range reflectValue.MapKeys() {
attrs[ToDBName(key.Interface().(string))] = reflectValue.MapIndex(key).Interface()
}
default:
for _, field := range (&Scope{Value: values}).Fields() {
if !field.IsBlank && !field.IsIgnored {
attrs[field.DBName] = field.Field.Interface()
}
}
}
}
return attrs
}
func equalAsString(a interface{}, b interface{}) bool {
return toString(a) == toString(b)
}
func toString(str interface{}) string {
if values, ok := str.([]interface{}); ok {
var results []string
for _, value := range values {
results = append(results, toString(value))
}
return strings.Join(results, "_")
} else if bytes, ok := str.([]byte); ok {
return string(bytes)
} else if reflectValue := reflect.Indirect(reflect.ValueOf(str)); reflectValue.IsValid() {
return fmt.Sprintf("%v", reflectValue.Interface())
}
return ""
}
func makeSlice(elemType reflect.Type) interface{} {
if elemType.Kind() == reflect.Slice {
elemType = elemType.Elem()
}
sliceType := reflect.SliceOf(elemType)
slice := reflect.New(sliceType)
slice.Elem().Set(reflect.MakeSlice(sliceType, 0, 0))
return slice.Interface()
}
func strInSlice(a string, list []string) bool {
for _, b := range list {
if b == a {
return true
}
}
return false
}
// getValueFromFields return given fields's value
func getValueFromFields(value reflect.Value, fieldNames []string) (results []interface{}) {
// If value is a nil pointer, Indirect returns a zero Value!
// Therefor we need to check for a zero value,
// as FieldByName could panic
if indirectValue := reflect.Indirect(value); indirectValue.IsValid() {
for _, fieldName := range fieldNames {
if fieldValue := indirectValue.FieldByName(fieldName); fieldValue.IsValid() {
result := fieldValue.Interface()
if r, ok := result.(driver.Valuer); ok {
result, _ = r.Value()
}
results = append(results, result)
}
}
}
return
}

View File

@ -1,131 +0,0 @@
package gorm
import (
"database/sql/driver"
"fmt"
"reflect"
"regexp"
"runtime"
"strings"
)
func fileWithLineNum() string {
for i := 2; i < 15; i++ {
_, file, line, ok := runtime.Caller(i)
if ok && (!regexp.MustCompile(`jinzhu/gorm/.*.go`).MatchString(file) || regexp.MustCompile(`jinzhu/gorm/.*test.go`).MatchString(file)) {
return fmt.Sprintf("%v:%v", file, line)
}
}
return ""
}
func isBlank(value reflect.Value) bool {
return reflect.DeepEqual(value.Interface(), reflect.Zero(value.Type()).Interface())
}
func toSearchableMap(attrs ...interface{}) (result interface{}) {
if len(attrs) > 1 {
if str, ok := attrs[0].(string); ok {
result = map[string]interface{}{str: attrs[1]}
}
} else if len(attrs) == 1 {
if attr, ok := attrs[0].(map[string]interface{}); ok {
result = attr
}
if attr, ok := attrs[0].(interface{}); ok {
result = attr
}
}
return
}
func convertInterfaceToMap(values interface{}) map[string]interface{} {
attrs := map[string]interface{}{}
switch value := values.(type) {
case map[string]interface{}:
for k, v := range value {
attrs[k] = v
}
case []interface{}:
for _, v := range value {
for key, value := range convertInterfaceToMap(v) {
attrs[key] = value
}
}
case interface{}:
reflectValue := reflect.ValueOf(values)
switch reflectValue.Kind() {
case reflect.Map:
for _, key := range reflectValue.MapKeys() {
attrs[ToDBName(key.Interface().(string))] = reflectValue.MapIndex(key).Interface()
}
default:
for _, field := range (&Scope{Value: values}).Fields() {
if !field.IsBlank && !field.IsIgnored {
attrs[field.DBName] = field.Field.Interface()
}
}
}
}
return attrs
}
func equalAsString(a interface{}, b interface{}) bool {
return toString(a) == toString(b)
}
func toString(str interface{}) string {
if values, ok := str.([]interface{}); ok {
var results []string
for _, value := range values {
results = append(results, toString(value))
}
return strings.Join(results, "_")
} else if bytes, ok := str.([]byte); ok {
return string(bytes)
} else if reflectValue := reflect.Indirect(reflect.ValueOf(str)); reflectValue.IsValid() {
return fmt.Sprintf("%v", reflectValue.Interface())
}
return ""
}
func makeSlice(elemType reflect.Type) interface{} {
if elemType.Kind() == reflect.Slice {
elemType = elemType.Elem()
}
sliceType := reflect.SliceOf(elemType)
slice := reflect.New(sliceType)
slice.Elem().Set(reflect.MakeSlice(sliceType, 0, 0))
return slice.Interface()
}
func strInSlice(a string, list []string) bool {
for _, b := range list {
if b == a {
return true
}
}
return false
}
// getValueFromFields return given fields's value
func getValueFromFields(value reflect.Value, fieldNames []string) (results []interface{}) {
// If value is a nil pointer, Indirect returns a zero Value!
// Therefor we need to check for a zero value,
// as FieldByName could panic
if indirectValue := reflect.Indirect(value); indirectValue.IsValid() {
for _, fieldName := range fieldNames {
if fieldValue := indirectValue.FieldByName(fieldName); fieldValue.IsValid() {
result := fieldValue.Interface()
if r, ok := result.(driver.Valuer); ok {
result, _ = r.Value()
}
results = append(results, result)
}
}
}
return
}