diff --git a/lib/DboBuilder/TableHandler/DataValidator.ts b/lib/DboBuilder/TableHandler/DataValidator.ts
index 9cca68b6..f7b7f7e9 100644
--- a/lib/DboBuilder/TableHandler/DataValidator.ts
+++ b/lib/DboBuilder/TableHandler/DataValidator.ts
@@ -332,8 +332,9 @@ const convertionFuncs: ConvertionFunc[] = [
     onlyAllowedFor: "update",
     getQuery: ({ args, column }) => {
       if (!args.length) throw "merge function requires at least one argument";
-      const argList = args.map(arg => asValue(arg)).join(" || ");
-      return `${asName(column.name)} || ${argList}`;
+      const argVals = args.map(arg => asValue(arg))
+      const argList = argVals.join(" || ");
+      return `COALESCE(${asName(column.name)}, ${argVals.join(", ")}) || ${argList}`;
     }
   }
 ];
diff --git a/lib/FileManager/FileManager.ts b/lib/FileManager/FileManager.ts
index 1f2e4123..329a32d0 100644
--- a/lib/FileManager/FileManager.ts
+++ b/lib/FileManager/FileManager.ts
@@ -264,11 +264,12 @@ export class FileManager {
     const { colName, tableName } = args;
     const tableConfig = this.prostgles?.opts.fileTable?.referencedTables?.[tableName];
     const isReferencingFileTable = this.dbo[tableName]?.columns?.some(c => c.name === colName && c.references && c.references?.some(({ ftable }) => ftable === this.tableName ));
+    const allowAllFiles = { acceptedContent: "*" } as const;
     if(isReferencingFileTable){
       if(tableConfig && typeof tableConfig !== "string"){
-        return tableConfig.referenceColumns[colName];
+        return tableConfig.referenceColumns[colName] ?? allowAllFiles;
       }
-      return { acceptedContent: "*" };
+      return allowAllFiles;
     }
     return undefined;
   }
diff --git a/package-lock.json b/package-lock.json
index 61f50fd3..89ef17b6 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "prostgles-server",
-  "version": "4.2.19",
+  "version": "4.2.20",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "prostgles-server",
-      "version": "4.2.19",
+      "version": "4.2.20",
       "license": "MIT",
       "dependencies": {
         "@types/express": "^4.17.13",
diff --git a/package.json b/package.json
index ac927949..f8eb948d 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "prostgles-server",
-  "version": "4.2.19",
+  "version": "4.2.20",
   "description": "",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",
diff --git a/tests/server/package-lock.json b/tests/server/package-lock.json
index 84c46930..e0b4626b 100644
--- a/tests/server/package-lock.json
+++ b/tests/server/package-lock.json
@@ -21,7 +21,7 @@
     },
     "../..": {
       "name": "prostgles-server",
-      "version": "4.2.19",
+      "version": "4.2.20",
       "license": "MIT",
       "dependencies": {
         "@types/express": "^4.17.13",