DB Schema/Characters: removed columns auctionhouse.item_template, character_inventory.item_template, guild_bank_item.item_entry and mail_items.item_template and created item_instance.itemEntry column instead of them.

As a side effect moved related queries to prepared statements.
As one more side effect fixed not shown and lost mail items in returned expired mail (patch by Quriq14).

--HG--
branch : trunk

sql/updates/10654_characters_item_instance.sql

@@ -0,0 +1,28 @@
+-- Add new column to item_instance table
+ALTER TABLE `item_instance` ADD COLUMN `itemEntry` mediumint(8) unsigned NOT NULL DEFAULT '0' AFTER `guid`;
+
+-- Set values for new column from corresponding columns in other tables
+UPDATE item_instance ii, auctionhouse ah
+SET ii.itemEntry = ah.item_template
+WHERE ii.guid = ah.itemguid;
+
+UPDATE item_instance ii, character_inventory ci
+SET ii.itemEntry = ci.item_template
+WHERE ii.guid = ci.item;
+
+UPDATE item_instance ii, guild_bank_item gbi
+SET ii.itemEntry = gbi.item_entry
+WHERE ii.guid = gbi.item_guid;
+
+UPDATE item_instance ii, mail_items mi
+SET ii.itemEntry = mi.item_template
+WHERE ii.guid = mi.item_guid;
+
+-- Remove unnecessary columns
+ALTER TABLE `auctionhouse` DROP COLUMN `item_template`;
+ALTER TABLE `character_inventory` DROP COLUMN `item_template`;
+ALTER TABLE `guild_bank_item` DROP COLUMN `item_entry`;
+ALTER TABLE `mail_items` DROP COLUMN `item_template`;
+
+-- Delete orphan records (use at your own risk)
+-- DELETE FROM item_instance WHERE itemEntry = 0;