Better support for scan into map, fix unfriendly data type for interface, close #3351

scan.go

@@ -2,12 +2,52 @@ package gorm
 
 import (
 	"database/sql"
+	"database/sql/driver"
 	"reflect"
 	"strings"
 
 	"gorm.io/gorm/schema"
 )
 
+func prepareValues(values []interface{}, db *DB, columnTypes []*sql.ColumnType, columns []string) {
+	if db.Statement.Schema != nil {
+		for idx, name := range columns {
+			if field := db.Statement.Schema.LookUpField(name); field != nil {
+				values[idx] = reflect.New(reflect.PtrTo(field.FieldType)).Interface()
+				continue
+			}
+			values[idx] = new(interface{})
+		}
+	} else if len(columnTypes) > 0 {
+		for idx, columnType := range columnTypes {
+			if columnType.ScanType() != nil {
+				values[idx] = reflect.New(reflect.PtrTo(columnType.ScanType())).Interface()
+			} else {
+				values[idx] = new(interface{})
+			}
+		}
+	} else {
+		for idx := range columns {
+			values[idx] = new(interface{})
+		}
+	}
+}
+
+func scanIntoMap(mapValue map[string]interface{}, values []interface{}, columns []string) {
+	for idx, column := range columns {
+		if reflectValue := reflect.Indirect(reflect.Indirect(reflect.ValueOf(values[idx]))); reflectValue.IsValid() {
+			mapValue[column] = reflectValue.Interface()
+			if valuer, ok := mapValue[column].(driver.Valuer); ok {
+				mapValue[column], _ = valuer.Value()
+			} else if b, ok := mapValue[column].(sql.RawBytes); ok {
+				mapValue[column] = string(b)
+			}
+		} else {
+			mapValue[column] = nil
+		}
+	}
+}
+
 func Scan(rows *sql.Rows, db *DB, initialized bool) {
 	columns, _ := rows.Columns()
 	values := make([]interface{}, len(columns))
@@ -15,9 +55,8 @@ func Scan(rows *sql.Rows, db *DB, initialized bool) {
 	switch dest := db.Statement.Dest.(type) {
 	case map[string]interface{}, *map[string]interface{}:
 		if initialized || rows.Next() {
-			for idx := range columns {
-				values[idx] = new(interface{})
-			}
+			columnTypes, _ := rows.ColumnTypes()
+			prepareValues(values, db, columnTypes, columns)
 
 			db.RowsAffected++
 			db.AddError(rows.Scan(values...))
@@ -28,38 +67,19 @@ func Scan(rows *sql.Rows, db *DB, initialized bool) {
 					mapValue = *v
 				}
 			}
-
-			for idx, column := range columns {
-				if v, ok := values[idx].(*interface{}); ok {
-					if v == nil {
-						mapValue[column] = nil
-					} else {
-						mapValue[column] = *v
-					}
-				}
-			}
+			scanIntoMap(mapValue, values, columns)
 		}
 	case *[]map[string]interface{}:
+		columnTypes, _ := rows.ColumnTypes()
 		for initialized || rows.Next() {
-			for idx := range columns {
-				values[idx] = new(interface{})
-			}
+			prepareValues(values, db, columnTypes, columns)
 
 			initialized = false
 			db.RowsAffected++
 			db.AddError(rows.Scan(values...))
 
 			mapValue := map[string]interface{}{}
-			for idx, column := range columns {
-				if v, ok := values[idx].(*interface{}); ok {
-					if v == nil {
-						mapValue[column] = nil
-					} else {
-						mapValue[column] = *v
-					}
-				}
-			}
-
+			scanIntoMap(mapValue, values, columns)
 			*dest = append(*dest, mapValue)
 		}
 	case *int, *int64, *uint, *uint64, *float32, *float64:

tests/query_test.go

@@ -6,6 +6,7 @@ import (
 	"regexp"
 	"sort"
 	"strconv"
+	"strings"
 	"testing"
 	"time"
 
@@ -61,6 +62,54 @@ func TestFind(t *testing.T) {
 			for _, name := range []string{"Name", "Age", "Birthday"} {
 				t.Run(name, func(t *testing.T) {
 					dbName := DB.NamingStrategy.ColumnName("", name)
+
+					switch name {
+					case "Name":
+						if _, ok := first[dbName].(string); !ok {
+							t.Errorf("invalid data type for %v, got %#v", dbName, first[dbName])
+						}
+					case "Age":
+						if _, ok := first[dbName].(uint); !ok {
+							t.Errorf("invalid data type for %v, got %#v", dbName, first[dbName])
+						}
+					case "Birthday":
+						if _, ok := first[dbName].(*time.Time); !ok {
+							t.Errorf("invalid data type for %v, got %#v", dbName, first[dbName])
+						}
+					}
+
+					reflectValue := reflect.Indirect(reflect.ValueOf(users[0]))
+					AssertEqual(t, first[dbName], reflectValue.FieldByName(name).Interface())
+				})
+			}
+		}
+	})
+
+	t.Run("FirstMapWithTable", func(t *testing.T) {
+		var first = map[string]interface{}{}
+		if err := DB.Table("users").Where("name = ?", "find").Find(first).Error; err != nil {
+			t.Errorf("errors happened when query first: %v", err)
+		} else {
+			for _, name := range []string{"Name", "Age", "Birthday"} {
+				t.Run(name, func(t *testing.T) {
+					dbName := DB.NamingStrategy.ColumnName("", name)
+					resultType := reflect.ValueOf(first[dbName]).Type().Name()
+
+					switch name {
+					case "Name":
+						if !strings.Contains(resultType, "string") {
+							t.Errorf("invalid data type for %v, got %v %#v", dbName, resultType, first[dbName])
+						}
+					case "Age":
+						if !strings.Contains(resultType, "int") {
+							t.Errorf("invalid data type for %v, got %v %#v", dbName, resultType, first[dbName])
+						}
+					case "Birthday":
+						if !strings.Contains(resultType, "Time") && !(DB.Dialector.Name() == "sqlite" && strings.Contains(resultType, "string")) {
+							t.Errorf("invalid data type for %v, got %v %#v", dbName, resultType, first[dbName])
+						}
+					}
+
 					reflectValue := reflect.Indirect(reflect.ValueOf(users[0]))
 					AssertEqual(t, first[dbName], reflectValue.FieldByName(name).Interface())
 				})
@@ -86,13 +135,29 @@ func TestFind(t *testing.T) {
 	t.Run("FirstSliceOfMap", func(t *testing.T) {
 		var allMap = []map[string]interface{}{}
 		if err := DB.Model(&User{}).Where("name = ?", "find").Find(&allMap).Error; err != nil {
-			t.Errorf("errors happened when query first: %v", err)
+			t.Errorf("errors happened when query find: %v", err)
 		} else {
 			for idx, user := range users {
 				t.Run("FindAllMap#"+strconv.Itoa(idx+1), func(t *testing.T) {
 					for _, name := range []string{"Name", "Age", "Birthday"} {
 						t.Run(name, func(t *testing.T) {
 							dbName := DB.NamingStrategy.ColumnName("", name)
+
+							switch name {
+							case "Name":
+								if _, ok := allMap[idx][dbName].(string); !ok {
+									t.Errorf("invalid data type for %v, got %#v", dbName, allMap[idx][dbName])
+								}
+							case "Age":
+								if _, ok := allMap[idx][dbName].(uint); !ok {
+									t.Errorf("invalid data type for %v, got %#v", dbName, allMap[idx][dbName])
+								}
+							case "Birthday":
+								if _, ok := allMap[idx][dbName].(*time.Time); !ok {
+									t.Errorf("invalid data type for %v, got %#v", dbName, allMap[idx][dbName])
+								}
+							}
+
 							reflectValue := reflect.Indirect(reflect.ValueOf(user))
 							AssertEqual(t, allMap[idx][dbName], reflectValue.FieldByName(name).Interface())
 						})
@@ -101,6 +166,43 @@ func TestFind(t *testing.T) {
 			}
 		}
 	})
+
+	t.Run("FindSliceOfMapWithTable", func(t *testing.T) {
+		var allMap = []map[string]interface{}{}
+		if err := DB.Table("users").Where("name = ?", "find").Find(&allMap).Error; err != nil {
+			t.Errorf("errors happened when query find: %v", err)
+		} else {
+			for idx, user := range users {
+				t.Run("FindAllMap#"+strconv.Itoa(idx+1), func(t *testing.T) {
+					for _, name := range []string{"Name", "Age", "Birthday"} {
+						t.Run(name, func(t *testing.T) {
+							dbName := DB.NamingStrategy.ColumnName("", name)
+							resultType := reflect.ValueOf(allMap[idx][dbName]).Type().Name()
+
+							switch name {
+							case "Name":
+								if !strings.Contains(resultType, "string") {
+									t.Errorf("invalid data type for %v, got %v %#v", dbName, resultType, allMap[idx][dbName])
+								}
+							case "Age":
+								if !strings.Contains(resultType, "int") {
+									t.Errorf("invalid data type for %v, got %v %#v", dbName, resultType, allMap[idx][dbName])
+								}
+							case "Birthday":
+								if !strings.Contains(resultType, "Time") && !(DB.Dialector.Name() == "sqlite" && strings.Contains(resultType, "string")) {
+									t.Errorf("invalid data type for %v, got %v %#v", dbName, resultType, allMap[idx][dbName])
+								}
+							}
+
+							reflectValue := reflect.Indirect(reflect.ValueOf(user))
+							AssertEqual(t, allMap[idx][dbName], reflectValue.FieldByName(name).Interface())
+						})
+					}
+				})
+			}
+		}
+	})
+
 }
 
 func TestQueryWithAssociation(t *testing.T) {