diff --git a/weed/command/scaffold.go b/weed/command/scaffold.go
index 52b547563..3296ebf21 100644
--- a/weed/command/scaffold.go
+++ b/weed/command/scaffold.go
@@ -102,6 +102,10 @@ enabled = false
 dir = "./filerrdb"					# directory to store rocksdb files
 
 [mysql]  # or memsql, tidb
+# Empty insertQuery will use the default insert query
+# example insertQuery can be for UPSERT syntax:
+# insertQuery = """INSERT INTO ` + "`%s`" + ` (dirhash,name,directory,meta) VALUES(?,?,?,?) ON DUPLICATE KEY UPDATE meta = VALUES(meta)"""
+insertQuery = ""
 # CREATE TABLE IF NOT EXISTS filemeta (
 #   dirhash     BIGINT               COMMENT 'first 64 bits of MD5 hash value of directory field',
 #   name        VARCHAR(1000) BINARY COMMENT 'directory or file name',
@@ -123,6 +127,10 @@ interpolateParams = false
 
 [mysql2]  # or memsql, tidb
 enabled = false
+# Empty insertQuery will use the default insert query
+# example insertQuery can be for UPSERT syntax:
+# insertQuery = """INSERT INTO ` + "`%s`" + ` (dirhash,name,directory,meta) VALUES(?,?,?,?) ON DUPLICATE KEY UPDATE meta = VALUES(meta)"""
+insertQuery = ""
 createTable = """
   CREATE TABLE IF NOT EXISTS ` + "`%s`" + ` (
     dirhash BIGINT,
@@ -143,6 +151,10 @@ connection_max_lifetime_seconds = 0
 interpolateParams = false
 
 [postgres] # or cockroachdb, YugabyteDB
+# Empty insertQuery will use the default insert query
+# example insertQuery can be for UPSERT syntax:
+# insertQuery = """INSERT INTO "%[1]s" (dirhash,name,directory,meta) VALUES($1,$2,$3,$4) ON CONFLICT ON CONSTRAINT "%[1]s_pkey" DO UPDATE SET meta = EXCLUDED.meta WHERE "%[1]s".meta != EXCLUDED.meta"""
+insertQuery = ""
 # CREATE TABLE IF NOT EXISTS filemeta (
 #   dirhash     BIGINT,
 #   name        VARCHAR(65535),
@@ -164,6 +176,10 @@ connection_max_lifetime_seconds = 0
 
 [postgres2]
 enabled = false
+# Empty insertQuery will use the default insert query
+# example insertQuery can be for UPSERT syntax:
+# insertQuery = """INSERT INTO "%[1]s" (dirhash,name,directory,meta) VALUES($1,$2,$3,$4) ON CONFLICT ON CONSTRAINT "%[1]s_pkey" DO UPDATE SET meta = EXCLUDED.meta WHERE "%[1]s".meta != EXCLUDED.meta"""
+insertQuery = ""
 createTable = """
   CREATE TABLE IF NOT EXISTS "%s" (
     dirhash   BIGINT,