unified-storage: fixes for sqlkv to work with postgres (#115961)

* unified-storage: fixes for sqlkv to work with postgres

pkg/storage/unified/resource/data/sqlkv_insert_datastore.sql

@@ -12,7 +12,7 @@ INSERT INTO {{ .Ident .TableName }}
 VALUES (
   {{ .Arg .GUID }},
   {{ .Arg .KeyPath }},
-  COALESCE({{ .Arg .Value }}, ""),
+  {{ .Arg .Value }},
   {{ .Arg .Group }},
   {{ .Arg .Resource }},
   {{ .Arg .Namespace }},

pkg/storage/unified/resource/data/sqlkv_insert_legacy_resource_history.sql

@@ -10,7 +10,7 @@ INSERT INTO {{ .Ident "resource_history" }}
   {{ .Ident "folder" }}
 )
 VALUES (
-  COALESCE({{ .Arg .Value }}, ""),
+  {{ .Arg .Value }},
   {{ .Arg .GUID }},
   {{ .Arg .Group }},
   {{ .Arg .Resource }},

pkg/storage/unified/resource/data/sqlkv_save_event.sql

@@ -5,7 +5,7 @@ INSERT INTO {{ .Ident .TableName }}
 )
 VALUES (
   {{ .Arg .KeyPath }},
-  COALESCE({{ .Arg .Value }}, "")
+  {{ .Arg .Value }}
 )
 {{- if eq .DialectName "mysql" }}
 ON DUPLICATE KEY UPDATE {{ .Ident "value" }} = {{ .Arg .Value }}