support scan assign slice cap (#5634)

* support scan assign slice cap * fix
go-gorm · Sep 22, 2022 · 35402e1 · 35402e1
1 parent c41ecf6
commit 35402e1
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/scan.go b/scan.go
@@ -248,7 +248,13 @@ func Scan(rows Rows, db *DB, mode ScanMode) {
 
 			if !update || reflectValue.Len() == 0 {
 				update = false
-				db.Statement.ReflectValue.Set(reflect.MakeSlice(reflectValue.Type(), 0, 20))
+				// if the slice cap is externally initialized, the externally initialized slice is directly used here
+				if reflectValue.Cap() == 0 {
+					db.Statement.ReflectValue.Set(reflect.MakeSlice(reflectValue.Type(), 0, 20))
+				} else {
+					reflectValue.SetLen(0)
+					db.Statement.ReflectValue.Set(reflectValue)
+				}
 			}
 
 			for initialized || rows.Next() {