VbzCart/docs/pieces/catalog/building

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Revision as of 21:58, 3 May 2009 by imported>Woozle (→‎SQL - queries - 2008: extracted 4 queries to separate pages; saving work)
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VbzCart: catalog building

Version

This is being revised yet again for the 2007 VbzCart-MySQL migration project; the previous version is here: VbzCart catalog building 2006.

Process

This is only a draft, as the process is still being worked out. Right now this process does not "recycle" junked records in cat_items; perhaps that was a bad idea to begin with, or perhaps some other use can be found for junked records that isn't part of catalog-building. There probably should be some process which removes junked records from use so they aren't taking up space and CPU cycles.

  1. Update the list of all catalog-based items ([calc Items Updates saved])
  2. For all items in [calc Items Updates saved] where ID_Item IS NULL, create new records in cat_items and update the corresponding records in [calc Items Updates saved]
  3. Fill in any blank ID_Item fields in [calc Items Updates saved] records:
    • #(Step 3) qryVb_Items_updates_index_new -- plugs the Item ID back into the calculated temp table. It assumes (1) 1:1 correspondence between Item IDs and catalog numbers, and (2) catalog numbers won't be changed during the course of a build (though they can change in general).
  4. Copy calculated item data over to [cat_items]:
  5. Final flag updates:
    • #(Step 5) qryVb_Items_update_final
      • Clear isInPrint flag for cat_items not found in calculated in-print listing
      • Set isForSale for cat_items with stock for sale
      • Update stock quantities for all cat_items
  6. Housekeeping: mark table as updated so cached tables get recalculated

SQL - queries - 2008

2008-03-15: Completely rewriting the building sequence again...

qryCtg_src_dups

Returns all duplicate records (each IDS_Item must be unique) in the generated source data. This should be performed as a check on data integrity before writing to cat_items; any duplicates may indicate a problem (typically, entering items from a new catalog but forgetting to mark the old one as superceded), and should be inspected. (Not sure if conflicts will prevent the update from completing; to be determined later.) <section begin=sql /><mysql>CREATE OR REPLACE VIEW qryCtg_src_dups AS SELECT IDS_Item, COUNT(IDS_Item) AS cntRows FROM qryCtg_src GROUP BY IDS_Item HAVING cntRows>1;</mysql> <section end=sql />

ctg_upd* data building

This is mostly working. A key issue seems to be the correct setting of isForSale. When we get to Stage 2:

  • ctg_upd1 has all the generated data from active sources; these items are all for sale
  • ctg_upd2 has joinable data from cat_items, i.e. anything which might be used (or revived) as a saleable item, i.e. anything where ID_Title is set. This includes a large number of items which will not be used. However, only items present in ctg_upd1 will cause a direct overwrite of cat_items, so we only need to save fields from cat_items which don't get set directly from ctg_upd1 (i.e. sourced items); items that are discontinued but in stock will not be overwritten, they will just have their stock status updated. This happens by setting those fields properly in ctg_upd2 (clear + calculate), then directly overwriting those fields in cat_items from the values in ctg_upd2. (Thus removing the need to clear those fields in cat_items even temporarily. This is the only reason we need ctg_upd2.)

The duplicate key count on ctg_upd2 should indicate how many different items share the same calculated IDS_Item. Ultimately, none of these should be items that are also for sale; perhaps a query should reality-check this after the update (for-sale items using duplicate IDSs), and warn the user if any records are found -- which would indicate a bug in the generation process.

During Stage 2, we first calculate (from scratch) quantities in stock and set the "for sale" flag for any items in stock (these go in ctg_upd2). Then we also set the "for sale" flag for any items which happen to have active sources, i.e. are in ctg_upd1.

  • TO DO:
    • at some point, we need a way to test for duplicate IDS_Item keys before the data gets put into ctg_upd1. Duplicate keys will probably cause this procedure to fail at that point, but I don't know if it will show an informative message if this happens or just fail silently (as it is, even when it completes successfully it says "query cancelled").
    • There should also be a check for catnums-needing-update but lacking CatSfx
  • History:
    • 2008-12-05 Added update of inactive catalog numbers (title's catalog number must match start of item's catalog number)

<mysql>DROP PROCEDURE IF EXISTS `doCtgUpdate`; CREATE PROCEDURE doCtgUpdate() MODIFIES SQL DATA BEGIN

/* STAGE 1: Clear/refill the two temporary tables from which cat_items is updated. */ 

 /* == Clear temp tables == */
 DELETE FROM ctg_upd1;
 DELETE FROM ctg_upd2;

 /* == Fill temp tables == */
   /* -- generated source data: */
 INSERT INTO ctg_upd1 SELECT
   CatSfx, isCloseOut, ID_CTG_Title, ID_CTG_Item, ID_Title, ID_ItTyp, ID_ItOpt, ID_ShipCost, PriceBuy, PriceSell, PriceList,
   ItOpt_Descr_part, NameSng, GrpItmDescr, TitleGroupDescr, OptionDescr, ItOpt_Sort,
   GrpCode, GrpDescr, GrpSort, IDS_Item, CatNum, ItOpt_Descr 
 FROM qryCtg_src;

   /* -- existing catalog data indexed for JOINing: */
 INSERT INTO ctg_upd2 SELECT *, 0 AS cntDups
 FROM qryCtg_Items_forUpdJoin
 ON DUPLICATE KEY UPDATE cntDups=cntDups+1;

/* STAGE 2: Calculate stock numbers and set isForSale flag */ 

  /* -- calculate stock quantities; set for-sale flag if in stock */
 UPDATE ctg_upd2 AS i LEFT JOIN v_stk_items_remaining AS s ON i.ID_Item=s.ID_Item
 SET
   i.qtyInStock=s.QtyForSale,
   i.isForSale=(s.QtyForSale > 0);

  /* -- also set for-sale flag if available from source */
 UPDATE ctg_upd2 AS i LEFT JOIN ctg_upd1 AS u ON i.IDS_Item=u.IDS_Item
 SET i.isForSale=i.isForSale OR (u.IDS_Item IS NOT NULL);

/* STAGE 3: Update cat_items */ 

  /* -- replace sourced items in cat_items from CTG data (except for fields saved in ctg_upd2) */
 REPLACE INTO cat_items
 SELECT *
 FROM qryCtg_Upd_join;

  /* -- set stock and for-sale fields for *all* joinable cat_items from calculations done in ctg_upd2 */
 UPDATE cat_items AS i LEFT JOIN ctg_upd2 AS u ON i.ID=u.ID_Item
 SET
   i.isForSale=u.isForSale,
   i.qtyInStock=u.qtyInStock;

  /* -- update inactive catalog numbers where title's catnum has changed */
 UPDATE cat_items AS i LEFT JOIN qryCat_Titles AS t ON i.ID_Title=t.ID
 SET
   i.CatNum=CONCAT_WS("-",t.CatNum,i.CatSfx)
 WHERE (LEFT(i.CatNum,LENGTH(t.CatNum)) != t.CatNum) AND NOT isPulled;

/* STAGE 4: Housekeeping - update timestamp of cat_items so dependent tables will be recalculated */ 

 UPDATE data_tables SET WhenUpdated=NOW() WHERE Name="cat_items";

END; </mysql> <section end=sql />

  • If this doesn't work as part of a script, check the actual syntax by editing the procedure in MySQL Query Browser.
  • REPLACE INTO is MySQL-specific syntax. The same thing could be accomplished in other more standard ways, but in the interest of time this seemed like the best way to get things working.

ctg build verifying

This displays any duplicate IDS_Items (ID_Title + CatSfx) found in currently active titles in cat_items. This is probably due to old records whose CatSfx fields weren't set (or weren't set properly) being (re)activated by being found in stock. <mysql>CREATE OR REPLACE VIEW qryCtgCk_dup_keys AS SELECT 

 i.CatNum,
 i.isInPrint,
 u.*

FROM ctg_upd2 AS u LEFT JOIN cat_items AS i ON u.ID_Item=i.ID WHERE cntDups and u.isForSale;</mysql>

SQL - queries

These are from the MS Access 97 version, gradually being honed down for migration to MySQL

(Step 1a) qryVb_Items_updates_new

<sql>SELECT c.* FROM qryCtg_Items_updates_joinable AS c LEFT JOIN ctg_updates AS s ON c.IDS_Item=s.IDS_Item WHERE s.IDS_Item IS NULL;</sql>

(Step 1) qryVb_Items_updates_append

<sql>INSERT INTO ctg_updates ( 

 ID_Item,
 IDS_Item,
 CatNum,
 CatSfx,
 ID_Title,
 ID_CTG_Group,
 ID_CTG_Title,
 ID_CTG_Item,
 ID_ItTyp,
 ID_ItOpt )

SELECT 

 0 AS ID_Item,
 IDS_Item,
 CatNum,
 CatSfx,
 ID_Title,
 ID_TGroup,
 ID_TGTitle,
 ID_TGItem,
 ID_ItTyp,
 ID_ItOpt

FROM qryVb_Items_Updates_new; </sql>

(Step 2) qryVb_Items_results_append

This adds new cat_items rows for any calculated items not already cross-referenced. It doesn't cross-reference them, however. That is done by the next query. <sql>INSERT INTO cat_items ( 

 CatNum,
 isForSale,
 isMaster,
 isInPrint,
 isCloseOut,
 ID_ItTyp,
 ID_ItOpt,
 ItOpt_Descr,
 ItOpt_Sort,
 ID_ShipCost,
 PriceBuy,
 PriceSell,
 PriceList )

SELECT 

 r.CatNum,
 r.isForSale,
 FALSE AS isMaster,
 r.isInPrint,
 r.isCloseOut,
 r.ID_ItTyp,
 r.ID_ItOpt,
 r.ItOpt_Descr,
 r.ItOpt_Sort,
 r.ID_ShipCost,
 r.PriceBuy,
 r.PriceSell,
 r.PriceList

FROM qryCtg_Items_updates AS r LEFT JOIN cat_items AS i ON r.ID_Item=i.ID WHERE i.ID IS NULL; </sql>

(Step 3) qryVb_Items_updates_index_new

This plugs the Item ID back into the calculated temp table. It assumes (1) 1:1 correspondence between Item IDs and catalog numbers, and (2) catalog numbers won't be changed during the course of a build (though they can change in general). <sql>UPDATE 

 ctg_updates AS s LEFT JOIN
 cat_items AS i

ON i.CatNum=s.CatNum SET 

 s.ID_Item = i.ID,
 isForSale = FALSE,
 isInPrint = FALSE

WHERE 

 s.ID_Item IS NULL;

</sql>

(Step 4) qryVb_Items_results_update

<sql>UPDATE 

 qryCtg_build AS r LEFT JOIN
 cat_items AS i

ON 

 r.ID_Item=i.ID

SET 

 i.CatNum = r.CatNum,
 i.isForSale = r.isForSale,
 i.isInPrint = r.isInPrint,
 i.isCloseOut = r.isCloseOut,
 i.isPulled = FALSE,
 i.isDumped = FALSE,
 i.ID_ItTyp = r.ID_ItTyp,
 i.ID_ItOpt = r.ID_ItOpt,
 i.ItOpt_Descr = iif(r.ItOpt_Descr IS NULL,i.ItOpt_Descr,r.ItOpt_Descr), 
 i.ItOpt_Sort = r.ItOpt_Sort,
 i.ID_ShipCost = r.ID_ShipCost,
 i.PriceBuy = r.PriceBuy,
 i.PriceSell = r.PriceSell,
 i.PriceList = r.PriceList,
 i.GrpCode = r.GrpCode,
 i.GrpDescr = r.GrpDescr,
 i.GrpSort = r.GrpSort,
 i.CatSfx = r.CatSfx

WHERE r.ID_Item IS NOT NULL; </sql>

Changes:

  • Must clear isPulled and isDumped, in case pulled items are returned to service

(Step 5) qryVb_Items_update_final

  • Clear isInPrint flag for cat_items not found in calculated in-print listing
  • Set isForSale for cat_items with stock for sale
  • Update stock quantities for all cat_items

<sql>UPDATE 

 (cat_items AS i LEFT JOIN qryCtg_build AS r ON r.ID_Item=i.ID)
 LEFT JOIN v_stk_items_remaining AS s ON s.ID_Item=i.ID

SET 

 i.isInPrint = nz(r.isInPrint),
 i.isCloseOut = nz(r.isCloseOut),
 i.isForSale = nz(r.isInPrint)
     OR nz(r.isCloseOut)
     OR (nz(s.QtyForSale) > 0),
 i.qtyInStock = nz(s.QtyForSale);

</sql>

(Step 6) qryVb_Items_mark_updated

<sql>UPDATE 

 data_tables

SET WhenUpdated=Now() WHERE Name="cat_items"</sql>

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