Fix affected rows for Scan, change affected rows count for row/rows to '-', close #3532

callbacks.go

@@ -74,7 +74,6 @@ func (cs *callbacks) Raw() *processor {
 func (p *processor) Execute(db *DB) {
 	curTime := time.Now()
 	stmt := db.Statement
-	db.RowsAffected = 0
 
 	if stmt.Model == nil {
 		stmt.Model = stmt.Dest

callbacks/row.go

@@ -16,6 +16,8 @@ func RowQuery(db *gorm.DB) {
 			} else {
 				db.Statement.Dest = db.Statement.ConnPool.QueryRowContext(db.Statement.Context, db.Statement.SQL.String(), db.Statement.Vars...)
 			}
+
+			db.RowsAffected = -1
 		}
 	}
 }

finisher_api.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"gorm.io/gorm/clause"
+	"gorm.io/gorm/logger"
 	"gorm.io/gorm/schema"
 	"gorm.io/gorm/utils"
 )
@@ -353,7 +354,9 @@ func (db *DB) Rows() (*sql.Rows, error) {
 
 // Scan scan value to a struct
 func (db *DB) Scan(dest interface{}) (tx *DB) {
+	currentLogger, newLogger := db.Logger, logger.Recorder.New()
 	tx = db.getInstance()
+	tx.Logger = newLogger
 	if rows, err := tx.Rows(); err != nil {
 		tx.AddError(err)
 	} else {
@@ -362,6 +365,11 @@ func (db *DB) Scan(dest interface{}) (tx *DB) {
 			tx.ScanRows(rows, dest)
 		}
 	}
+
+	currentLogger.Trace(tx.Statement.Context, newLogger.BeginAt, func() (string, int64) {
+		return newLogger.SQL, tx.RowsAffected
+	}, tx.Error)
+	tx.Logger = currentLogger
 	return
 }
 

logger/logger.go

@@ -63,6 +63,7 @@ var (
 		LogLevel:      Warn,
 		Colorful:      true,
 	})
+	Recorder = traceRecorder{Interface: Default}
 )
 
 func New(writer Writer, config Config) Interface {
@@ -70,18 +71,18 @@ func New(writer Writer, config Config) Interface {
 		infoStr      = "%s\n[info] "
 		warnStr      = "%s\n[warn] "
 		errStr       = "%s\n[error] "
-		traceStr     = "%s\n[%.3fms] [rows:%d] %s"
-		traceWarnStr = "%s\n[%.3fms] [rows:%d] %s"
-		traceErrStr  = "%s %s\n[%.3fms] [rows:%d] %s"
+		traceStr     = "%s\n[%.3fms] [rows:%v] %s"
+		traceWarnStr = "%s\n[%.3fms] [rows:%v] %s"
+		traceErrStr  = "%s %s\n[%.3fms] [rows:%v] %s"
 	)
 
 	if config.Colorful {
 		infoStr = Green + "%s\n" + Reset + Green + "[info] " + Reset
 		warnStr = BlueBold + "%s\n" + Reset + Magenta + "[warn] " + Reset
 		errStr = Magenta + "%s\n" + Reset + Red + "[error] " + Reset
-		traceStr = Green + "%s\n" + Reset + Yellow + "[%.3fms] " + BlueBold + "[rows:%d]" + Reset + " %s"
-		traceWarnStr = Green + "%s\n" + Reset + RedBold + "[%.3fms] " + Yellow + "[rows:%d]" + Magenta + " %s" + Reset
-		traceErrStr = RedBold + "%s " + MagentaBold + "%s\n" + Reset + Yellow + "[%.3fms] " + BlueBold + "[rows:%d]" + Reset + " %s"
+		traceStr = Green + "%s\n" + Reset + Yellow + "[%.3fms] " + BlueBold + "[rows:%v]" + Reset + " %s"
+		traceWarnStr = Green + "%s\n" + Reset + RedBold + "[%.3fms] " + Yellow + "[rows:%v]" + Magenta + " %s" + Reset
+		traceErrStr = RedBold + "%s " + MagentaBold + "%s\n" + Reset + Yellow + "[%.3fms] " + BlueBold + "[rows:%v]" + Reset + " %s"
 	}
 
 	return &logger{
@@ -138,13 +139,43 @@ func (l logger) Trace(ctx context.Context, begin time.Time, fc func() (string, i
 		switch {
 		case err != nil && l.LogLevel >= Error:
 			sql, rows := fc()
-			l.Printf(l.traceErrStr, utils.FileWithLineNum(), err, float64(elapsed.Nanoseconds())/1e6, rows, sql)
+			if rows == -1 {
+				l.Printf(l.traceErrStr, utils.FileWithLineNum(), err, float64(elapsed.Nanoseconds())/1e6, "-", sql)
+			} else {
+				l.Printf(l.traceErrStr, utils.FileWithLineNum(), err, float64(elapsed.Nanoseconds())/1e6, rows, sql)
+			}
 		case elapsed > l.SlowThreshold && l.SlowThreshold != 0 && l.LogLevel >= Warn:
 			sql, rows := fc()
-			l.Printf(l.traceWarnStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, rows, sql)
+			if rows == -1 {
+				l.Printf(l.traceWarnStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, "-", sql)
+			} else {
+				l.Printf(l.traceWarnStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, rows, sql)
+			}
 		case l.LogLevel >= Info:
 			sql, rows := fc()
-			l.Printf(l.traceStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, rows, sql)
+			if rows == -1 {
+				l.Printf(l.traceStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, "-", sql)
+			} else {
+				l.Printf(l.traceStr, utils.FileWithLineNum(), float64(elapsed.Nanoseconds())/1e6, rows, sql)
+			}
 		}
 	}
 }
+
+type traceRecorder struct {
+	Interface
+	BeginAt      time.Time
+	SQL          string
+	RowsAffected int64
+	Err          error
+}
+
+func (l traceRecorder) New() *traceRecorder {
+	return &traceRecorder{Interface: l.Interface}
+}
+
+func (l *traceRecorder) Trace(ctx context.Context, begin time.Time, fc func() (string, int64), err error) {
+	l.BeginAt = begin
+	l.SQL, l.RowsAffected = fc()
+	l.Err = err
+}

scan.go

@@ -52,6 +52,7 @@ func scanIntoMap(mapValue map[string]interface{}, values []interface{}, columns
 func Scan(rows *sql.Rows, db *DB, initialized bool) {
 	columns, _ := rows.Columns()
 	values := make([]interface{}, len(columns))
+	db.RowsAffected = 0
 
 	switch dest := db.Statement.Dest.(type) {
 	case map[string]interface{}, *map[string]interface{}: