diff --git a/include/lehrverband.class.php b/include/lehrverband.class.php
index dbe16d26e..ca751feb3 100644
--- a/include/lehrverband.class.php
+++ b/include/lehrverband.class.php
@@ -57,9 +57,9 @@ class lehrverband extends basis_db
 	{
 		$qry = "SELECT count(*) as anzahl FROM public.tbl_lehrverband WHERE
 		            studiengang_kz=".$this->db_add_param($studiengang_kz, FHC_INTEGER)." AND
-		            semester=".$this->db_add_param($semester, FHC_INTEGER)." AND
-		            trim(verband)=".trim($this->db_add_param($verband))." AND
-		            trim(gruppe)=".trim($this->db_add_param($gruppe)).";";
+		            semester=".$this->db_add_param($semester, FHC_INTEGER, false)." AND
+		            trim(verband)=".$this->db_add_param(trim($verband), FHC_STRING, false)." AND
+		            trim(gruppe)=".$this->db_add_param(trim($gruppe), FHC_STRING, false).";";
 
 		if($this->db_query($qry))
 		{
@@ -248,4 +248,4 @@ class lehrverband extends basis_db
 		}
 	}
 }
-?>
\ No newline at end of file
+?>
diff --git a/include/pgsql.class.php b/include/pgsql.class.php
index 1b81ec749..b67b5cee2 100644
--- a/include/pgsql.class.php
+++ b/include/pgsql.class.php
@@ -230,7 +230,7 @@ class basis_db extends db
 			if($nullable)
 				return 'null';
 			else
-				return '';
+				return "''";
 		}
 
 		switch($type)