Paginación de access

sqlquerybuilder/__init__.py

@@ -241,7 +241,6 @@ class SQLQuery(object):
         self._limits = None
         self._sql = sql
         self._nolock = False
-        self._distinct = False
 
     def has_filters(self,):
         return self._order_by or self._group_by or self._joins\
@@ -273,11 +272,6 @@ class SQLQuery(object):
         clone._nolock = enabled
         return clone
 
-    def distinct(self, enabled=True):
-        clone = self._clone()
-        clone._distinct = enabled
-        return clone
-
     def filter(self, *args, **kwargs):
         clone = self._clone()
         clone._filters &= self._q(*args, **kwargs)
@@ -298,6 +292,9 @@ class SQLQuery(object):
         clone._group_by = args
         return clone
 
+    def first(self):
+        return self[:1]
+
     def join(self, table, on="", how="inner join"):
         clone = self._clone()
         if on:
@@ -380,11 +377,6 @@ class SQLCompiler(object):
             return " WITH (NOLOCK)"
         return ""
 
-    def get_distinct(self,):
-        if self._distinct:
-            return " DISTINCT "
-        return ""
-
     def get_limits(self,):
         if self._limits and self.sql_mode != "SQL_SERVER":
             offset = self._limits.start
@@ -408,10 +400,7 @@ class SQLCompiler(object):
         else:
             table = self.get_table()
 
-        sql = ["SELECT",
-               self.get_distinct(),
-               self.get_top(),
-               self.get_columns(),
+        sql = ["SELECT", self.get_top(), self.get_columns(),
                "FROM", table,
                self.get_nolock(),
                self.get_joins(), self.get_where(),
@@ -437,6 +426,31 @@ class SQLCompiler(object):
                     self.get_group_by(),
                     self.get_limits(), ") as tbl_paginated WHERE ", conds]
 
+        if self.sql_mode == "ACCESS" and self._limits and \
+           self._limits.start is not None and self._limits.stop is not None:
+            conds = []
+
+            if self._limits.start is not None:
+                conds.append("row_number > %s" % self._limits.start)
+
+            if self._limits.stop is not None:
+                conds.append("row_number <= %s" % self._limits.stop)
+
+            conds = " AND ".join(conds)
+            count = "(select count(*) FROM {table} as t2 WHERE t2.{id} <= {table}.{id}) as row_number".format(table=table,
+                                                                                                              id=self._order_by[0])
+
+            return ["SELECT * FROM (", "SELECT", self.get_columns(), ",",
+                    count,
+                    # "FROM",
+                    # table,
+                    self.get_joins(),
+                    self.get_where(),
+                    self.get_group_by(),
+                    " FROM ",
+                    table,
+                    ") WHERE ", conds]
+
         return sql
 
     def _compile(self):