From 07e2d4e4c5af45da62a9cd4082cc22b926713ded Mon Sep 17 00:00:00 2001
From: michael <michael@freepascal.org>
Date: Thu, 30 Apr 2020 10:43:03 +0000
Subject: [PATCH] * Avoid errors when dataset is not active while constructing
 update SQL.

git-svn-id: trunk@45189 -
---
 packages/fcl-db/src/sqldb/sqldb.pp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/fcl-db/src/sqldb/sqldb.pp b/packages/fcl-db/src/sqldb/sqldb.pp
index b69cde538e..af867e6aaf 100644
--- a/packages/fcl-db/src/sqldb/sqldb.pp
+++ b/packages/fcl-db/src/sqldb/sqldb.pp
@@ -2017,7 +2017,8 @@ begin
      if (sql_where<>'') then
        sql_where:=sql_where + ' and ';
      sql_where:= sql_where + '(' + FieldNameQuoteChars[0] + F.FieldName + FieldNameQuoteChars[1];
-     if F.OldValue = NULL then
+     // primary key normally cannot be null
+     if Assigned(F.Dataset) and F.Dataset.Active and (F.OldValue = NULL) then
         sql_where :=  sql_where + ' is null '
      else
         sql_where :=  sql_where +'= :"' + 'OLD_' + F.FieldName + '"';