X-Git-Url: http://git.kpe.io/?p=clsql.git;a=blobdiff_plain;f=sql%2Fexpressions.lisp;h=50aa5d1fd478942ec8dfdd6eebd15f6d1bb4d252;hp=fb9f3f7ea555c18480729a0e7d678f674f725813;hb=fdd069770e32d0cfa4b66d6e5cfd4540197660ba;hpb=e622ee6f4bf2b9fe81af59d566e651c983a4833b

diff --git a/sql/expressions.lisp b/sql/expressions.lisp
index fb9f3f7..50aa5d1 100644
--- a/sql/expressions.lisp
+++ b/sql/expressions.lisp
@@ -1,7 +1,7 @@
 ;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
 ;;;; *************************************************************************
 ;;;;
-;;;; $Id: 
+;;;; $Id$
 ;;;;
 ;;;; Classes defining SQL expressions and methods for formatting the
 ;;;; appropriate SQL commands.
@@ -186,11 +186,6 @@
     sql
     `(make-instance 'sql-ident-table :name ',name :table-alias ',alias)))
 
-(defun generate-sql (expr database)
-  (let ((*sql-stream* (make-string-output-stream)))
-    (output-sql expr database)
-    (get-output-stream-string *sql-stream*)))
-
 (defmethod output-sql ((expr sql-ident-table) database)
   (with-slots (name alias)
     expr
@@ -374,12 +369,14 @@
                        :test (lambda (tab1 tab2)
                                (equal (slot-value tab1 'name)
                                       (slot-value tab2 'name))))))
+(defvar *in-subselect* nil)
 
 (defmethod output-sql ((expr sql-function-exp) database)
   (with-slots (name args)
     expr
     (output-sql name database)
-    (when args (output-sql args database)))
+    (let ((*in-subselect* nil)) ;; aboid double parens
+      (when args (output-sql args database))))
   t)
 
 
@@ -563,8 +560,6 @@ uninclusive, and the args from that keyword to the end."
 			   :group-by group-by :having having :order-by order-by
 			   :inner-join inner-join :on on))))))
 
-(defvar *in-subselect* nil)
-
 (defmethod output-sql ((query sql-query) database)
   (with-slots (distinct selections from where group-by having order-by
                         limit offset inner-join on all set-operation) 
@@ -583,10 +578,21 @@ uninclusive, and the args from that keyword to the end."
     (output-sql (apply #'vector selections) database)
     (when from
       (write-string " FROM " *sql-stream*)
-      (typecase from 
-        (list (output-sql (apply #'vector from) database))
-        (string (write-string from *sql-stream*))
-        (t (output-sql from database))))
+      (flet ((ident-table-equal (a b) 
+               (and (if (and (eql (type-of a) 'sql-ident-table)
+                             (eql (type-of b) 'sql-ident-table))
+                        (string-equal (slot-value a 'alias)
+                                      (slot-value b 'alias))
+                        t)
+                    (string-equal (symbol-name (slot-value a 'name))
+                                  (symbol-name (slot-value b 'name))))))
+        (typecase from 
+          (list (output-sql (apply #'vector 
+                                   (remove-duplicates from 
+                                                      :test #'ident-table-equal))
+                            database))
+          (string (write-string from *sql-stream*))
+          (t (output-sql from database)))))
     (when inner-join
       (write-string " INNER JOIN " *sql-stream*)
       (output-sql inner-join database))
@@ -841,16 +847,6 @@ uninclusive, and the args from that keyword to the end."
 ;; Convert type spec to sql syntax
 ;;
 
-(defmethod database-constraint-description (constraint database)
-  (declare (ignore database))
-  (let ((output (assoc (symbol-name constraint) *constraint-types*
-                       :test #'equal)))
-    (if (null output)
-        (error 'sql-user-error
-               :message (format nil "unsupported column constraint '~A'"
-				constraint))
-        (cdr output))))
-
 (defmethod database-constraint-statement (constraint-list database)
   (declare (ignore database))
   (make-constraints-description constraint-list))