Refrain from TRUNCAT'ing an empty list of tables.

Fixed #789.

src/pgsql/pgsql-create-schema.lisp

@@ -167,10 +167,14 @@
                                 (schema  (table-list catalog-or-table))
                                 (table   (list catalog-or-table)))))
          (sql
-          (format nil "TRUNCATE ~{~a~^,~};" target-list)))
-    (pgsql-execute sql)
-    ;; return how many tables we just TRUNCATEd
-    (length target-list)))
+          (when target-list
+            (format nil "TRUNCATE ~{~a~^,~};" target-list))))
+    (if target-list
+        (progn
+          (pgsql-execute sql)
+          ;; return how many tables we just TRUNCATEd
+          (length target-list))
+        0)))
 
 (defun disable-triggers (table-name)
   "Disable triggers on TABLE-NAME. Needs to be called with a PostgreSQL

test/mysql/db789.load

@@ -0,0 +1,17 @@
+LOAD DATABASE
+     FROM mysql://root@localhost/db789
+     INTO postgres:///pgloader
+
+  WITH data only, truncate, create no tables
+
+  MATERIALIZE VIEWS proceed
+
+  INCLUDING ONLY TABLE NAMES MATCHING 'proceed'
+
+  BEFORE LOAD DO
+  $$ drop schema if exists matview cascade; $$,
+  $$ drop schema if exists db789 cascade; $$,
+  $$ create schema db789; $$,
+  $$ create table db789.refrain (id char(1) primary key); $$,
+  $$ create table db789.proceed (id char(1) primary key); $$;
+

test/mysql/db789.sql

@@ -0,0 +1,8 @@
+drop database if exists db789;
+create database db789;
+use db789;
+
+create table refrain (id char(1) primary key);
+insert into refrain values ('a'), ('b'), ('c'), ('d');
+
+create view proceed as select * from refrain where id > 'b';