Modify the database schema for the table list2 (eval, query).

docs/db_schema/database.xml

@@ -362,7 +362,10 @@
 <datatype>integer</datatype>
 <relation table="events" row="id" />
 </row>
-<row name="transform" null="1" autoincrement="0">
+<row name="eval" null="1" autoincrement="0">
+<datatype>string</datatype>
+<default>NULL</default></row>
+<row name="query" null="1" autoincrement="0">
 <datatype>string</datatype>
 <default>NULL</default></row>
 <row name="group_field" null="1" autoincrement="0">

modules/plugin_event/model_report.py

@@ -196,7 +196,8 @@ class Report(object):
                   notnull=True,
                   label="Event"),
 
-            Field("transform", "text"),
+            Field("eval", "text"),
+            Field("query", "text"),
 
             Field("group_field",
                   "string",
@@ -205,11 +206,9 @@ class Report(object):
 
             Field("sorters", "list:string", comment=TP_SORTERS),
 
-            Field("columns",
-                  "text",
+            Field("columns", "text",
                   default=def_columns,
-                  comment=T(TP_COLUMNS),
-                  notnull=True),
+                  comment=T(TP_COLUMNS)),
 
             Field("features",
                   "text",

modules/plugin_event/report_tools.py

@@ -118,8 +118,11 @@ class List2(object):
 
         df = func(**criteria)
 
-        if not df.empty and config.transform not in (None, ""):
-            df.eval(config.transform, inplace=True)
+        if not df.empty and config.eval not in (None, ""):
+            df.eval(config.eval, inplace=True)
+
+        if not df.empty and config.query not in (None, ""):
+            df.query(config.query, inplace=True)
 
         # ....................................................................
         #

modules/plugin_event/ui_report.py

@@ -10,6 +10,20 @@ formModifier = dbui.FormModifier
 gridModifier = dbui.GridModifier
 storeModifier = dbui.StoreModifier
 
+COLUMN_GUIDE = "All columns will be created when the field is empty"
+
+EVAL_GUIDE = """
+It is possible to transform the source by creating new columns from existing
+ ones using arithmetical expressions. The expression is written in natural
+ language with one assignment per line. For more details have a look to the
+ function pandas.eval and to the method pandas.DataFrame.eval.
+"""
+
+QUERY_GUIDE = """
+It is possible to select data by applying a query on fields of the source.
+ The query is written in natural language using and / or operator.
+ For more details have a look to the method pandas.DataFrame.query.
+"""
 
 class ReportUi(object):
 
@@ -205,12 +219,19 @@ class ReportUi(object):
 
         mdf.configure_field("columns",
                             editorHeight=240,
-                            hideLabel=True,
+                            fieldLabel=COLUMN_GUIDE,
+                            hideLabel=False,
+                            labelAlign="top",
                             language="json",
                             xtype="xaceeditorfield")
 
         mdf.configure_field("definition", height=100)
 
+        mdf.configure_field("eval",
+                            emptyText=EVAL_GUIDE,
+                            height=120,
+                            hideLabel=True)
+
         mdf.configure_field("features",
                             editorHeight=240,
                             hideLabel=True,
@@ -219,17 +240,16 @@ class ReportUi(object):
 
         mdf.configure_field("id_events", emptyText=" ")
 
+        mdf.configure_field("query",
+                            emptyText=QUERY_GUIDE,
+                            height=120,
+                            hideLabel=True)
+
         mdf.configure_field("sorters",
                             height=210,
                             hideHeader=True,
                             minimumRows=10)
 
-        mdf.configure_field("transform",
-                            editorHeight=240,
-                            hideLabel=True,
-                            language="python",
-                            xtype="xaceeditorfield")
-
         #.....................................................................
         #
         # Form
@@ -243,13 +263,14 @@ class ReportUi(object):
                          "definition",
                          title=T("General"))
 
-        mdf.merge_fields("transform",
-                         title=T("Transform"))
-
         mdf.merge_fields("group_field",
                          "sorters",
                          title=T("Group"))
 
+        mdf.merge_fields("eval",
+                         "query",
+                         title=T("Transform"))
+
         mdf.merge_fields("columns",
                          title=T("Columns"))
 
@@ -267,14 +288,15 @@ class ReportUi(object):
         mdf.configure_column("name", width=30)
         mdf.hide_columns("columns",
                          "conditions",
+                         "eval",
                          "features",
                          "group_field",
                          "id_events",
                          "kwargs",
+                         "query",
                          "sorters",
                          "source",
-                         "title",
-                         "transform")
+                         "title")
 
         #.....................................................................
         #