X-Git-Url: http://git.kpe.io/?p=clsql.git;a=blobdiff_plain;f=sql%2Fexpressions.lisp;fp=sql%2Fexpressions.lisp;h=29363afbdbdda080c79ecacad004f26cb1a87d33;hp=983d4a526bb5667e1eb6fa17f2c6090c15f93823;hb=7b89378f8c7b8437bef05f9b50f3613099ea41c0;hpb=39e2802cd264ddacb3ca59b3b2c5c38f202149de

diff --git a/sql/expressions.lisp b/sql/expressions.lisp
index 983d4a5..29363af 100644
--- a/sql/expressions.lisp
+++ b/sql/expressions.lisp
@@ -1182,3 +1182,51 @@ uninclusive, and the args from that keyword to the end."
       (%sql-expression (flatten-id name))
       )))
 
+(defun %clsql-subclauses (clauses)
+  "a helper for dealing with lists of sql clauses"
+  (loop for c in clauses
+        when c
+        collect (typecase c
+                  (string (clsql-sys:sql-expression :string c))
+                  (T c))))
+
+(defun clsql-ands (clauses)
+  "Correctly creates a sql 'and' expression for the clauses
+    ignores any nil clauses
+    returns a single child expression if there is only one
+    returns an 'and' expression if there are many
+    returns nil if there are no children"
+  (let ((ex (%clsql-subclauses clauses)))
+    (when ex
+      (case (length ex)
+        (1 (first ex))
+        (t (apply #'clsql-sys:sql-and ex))))))
+
+(defun clsql-and (&rest clauses)
+  "Correctly creates a sql 'and' expression for the clauses
+    ignores any nil clauses
+    returns a single child expression if there is only one
+    returns an 'and' expression if there are many
+    returns nil if there are no children"
+  (clsql-ands clauses))
+
+(defun clsql-ors (clauses)
+  "Correctly creates a sql 'or' expression for the clauses
+    ignores any nil clauses
+    returns a single child expression if there is only one
+    returns an 'or' expression if there are many
+    returns nil if there are no children"
+  (let ((ex (%clsql-subclauses clauses)))
+    (when ex
+      (case (length ex)
+        (1 (first ex))
+        (t (apply #'clsql-sys:sql-or ex))))))
+
+(defun clsql-or (&rest clauses)
+  "Correctly creates a sql 'or' expression for the clauses
+    ignores any nil clauses
+    returns a single child expression if there is only one
+    returns an 'or' expression if there are many
+    returns nil if there are no children"
+  (clsql-ors clauses))
+