From: Michael Orlitzky <michael@orlitzky.com>
Date: Mon, 20 Jan 2014 16:05:31 +0000 (-0500)
Subject: Update the schema documentation.
X-Git-Tag: 0.0.1~34
X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=9f3133c83b714b9068f01e8d508023bdbed70aa9;p=dead%2Fhtsn-import.git

Update the schema documentation.
Add ON DELETE CASCADE for the references in TSN.XML.Odds.
---

diff --git a/doc/man1/htsn-import.1 b/doc/man1/htsn-import.1
index 66506c6..957382d 100644
--- a/doc/man1/htsn-import.1
+++ b/doc/man1/htsn-import.1
@@ -68,19 +68,27 @@ that we import. For example, the documents corresponding to
 These top-level tables will often have children. For example, each
 news item has zero or more locations associated with it. The child
 table will be named <parent>_<children>, which in this case
-corresponsds to \(dqnews_locations\(dq.
+corresponds to \(dqnews_locations\(dq.
 .P
-To relate the two, a third table exists with name <parent
+To relate the two, a third table may exist with name <parent
 table>__<child table>. Note the two underscores. This prevents
-ambiguity when the child table itself contains underscores. As long we
-never go more than one level down, this system should suffice. The
-table joining \(dqnews\(dq with \(dqnews_locations\(dq is thus called
+ambiguity when the child table itself contains underscores. The table
+joining \(dqnews\(dq with \(dqnews_locations\(dq is thus called
 \(dqnews__news_locations\(dq.
 .P
-Wherever possible, children are kept unique to prevent pointless
-duplication. This slows down inserts, and speeds up reads (which we
-assume are much more frequent). The current rate at which the feed
-transmits XML is much too slow to cause problems inserting.
+Where it makes sense, children are kept unique to prevent pointless
+duplication. This slows down inserts, and speeds up reads (which are
+much more frequent). There is a tradeoff to be made, however. For a
+table with a small, fixed upper bound on the number of rows (like
+\(dqodds_casinos\(dq), there is great benefit to de-duplication. The
+total number of rows stays small, so inserts are still quick, and many
+duplicate rows are eliminated.
+.P
+But, with a table like \(dqodds_games\(dq, the number of games grows
+quickly and without bound. It is therefore more beneficial to be able
+to delete the old games (though an ON DELETE CASCADE, tied to
+\(dqodds\(dq) than it is to eliminate duplication. A table like
+\(dqnews_locations\(dq is somewhere in-between.
 .P
 UML diagrams of the resulting database schema for each XML document
 type are provided with the \fBhtsn-import\fR documentation.
diff --git a/src/TSN/XML/Odds.hs b/src/TSN/XML/Odds.hs
index 10d34a4..67ddbd4 100644
--- a/src/TSN/XML/Odds.hs
+++ b/src/TSN/XML/Odds.hs
@@ -434,11 +434,27 @@ mkPersist tsn_codegen_config [groundhog|
       fields:
         - name: odds_OddsGame0 # Default created by mkNormalFieldName
           dbName: odds_id
+          reference:
+            onDelete: cascade
         - name: odds_OddsGame1 # Default created by mkNormalFieldName
           dbName: odds_games_id
+          reference:
+            onDelete: cascade
 
 - entity: OddsGame_OddsGameTeam
   dbName: odds_games__odds_games_teams
+  constructors:
+    - name: OddsGame_OddsGameTeam
+      fields:
+        - name: ogogt_odds_games_id
+          reference:
+            onDelete: cascade
+        - name: ogogt_away_team_id
+          reference:
+            onDelete: cascade
+        - name: ogogt_home_team_id
+          reference:
+            onDelete: cascade
 |]
 
 instance DbImport Message where