SEARCH several Tables IN SQL
I'm trying to search several tables at once for a search term. My query is:
SELECT item.ItemID
FROM Inventory.Item item
JOIN Inventory.Category catR // each item can be in several categories
ON catR.ItemID = item.ItemID
JOIN Category.Category cat
ON cat.CategoryID = catR.CategoryID
JOIN Inventory.Brand bran
ON bran.BrandID = item.BrandID
WHERE
item.Description LIKE '%' + @term + '%'
OR
item.Description LIKE '%' + @term
OR
item.Description LIKE @term + '%'
OR
item.Description = @term
OR
cat.CategoryName LIKE '%' + @term + '%'
//same pattern as item.Description used to search CategoryName
//...
OR
bran.BrandName LIKE '%' + @term + '%'
//same pattern as item.Description used to search BrandName
//...
But the results are not as expected. I have about 50 items in the category "Casement" but when term == "Casement" only items that have "Casement" in their item.Description will be returned.
开发者_高级运维Am I doing something wrong? Should I do this a better way?
Its enough to write
item.Description LIKE '%' + @term + '%'
instead of
item.Description LIKE '%' + @term + '%'
OR
item.Description LIKE '%' + @term
OR
item.Description LIKE @term + '%'
OR
item.Description = @term
Conceptually I would keep it simple and then change it from there if needed for performance. First I would create a view and then do the select off of that.
CREATE VIEW vSearchTables
AS
SELECT item.ItemID, 'Item' AS TableName, item.Descripton AS Txt
FROM Inventory.Item item
UNION ALL
SELECT catR.ItemID, 'Category' AS TableName, cat.CategoryName AS Txt
FROM Inventory.Category catR
JOIN Category.Category cat
ON cat.CategoryID = catR.CategoryID
UNION ALL
SELECT item.ItemID, 'Brand' AS TableName, bran.BrandName AS Txt
FROM Inventory.Item item
JOIN Inventory.Brand bran
ON bran.BrandID = item.BrandID
GO
SELECT ItemID
FROM vSearchTables
WHERE Txt LIKE '%'+@term +'%'
GO
If you have sql2005 and want to test this concept you can run the following:
CREATE VIEW vSearchTables
AS
select object_name(o.object_id) Object, o.type, m.definition as Txt
from sys.sql_modules m
join sys.objects o on m.object_id = o.object_id
GO
SELECT *
FROM vSearchTables
WHERE Txt LIKE '%TRIGGER%'
This is a good CTE example:
WITH items AS (
SELECT i.itemid,
i.description,
cat.category_name,
b.brandname
FROM INVENTORY.ITEM i
LEFT JOIN INVENTORY.CATEGORY c ON c.itemid = i.itemid
LEFT JOIN CATEGORY.CATEGORY cat ON cat.CategoryID = c.categoryid
LEFT JOIN INVENTORY.BRAND b ON b.brandid = i.brandid)
SELECT a.itemid
FROM items a
WHERE a.description LIKE '%' + @term + '%'
UNION ALL
SELECT b.itemid
FROM items b
WHERE b.categoryname LIKE '%' + @term + '%'
UNION ALL
SELECT c.itemid
FROM items c
WHERE c.brandname LIKE '%' + @term + '%'
CTEs are supported in SQL Server 2005+.
Try this:
Select i.ItemID
From Inventory.Item i
Join Inventory.Category ic
On ic.ItemID = i.ItemID
Join Category.Category cc
On cat.CategoryID = ic.CategoryID
Join Inventory.Brand ib
On ib.BrandID = i.BrandID
Where CharIndex(@Term,
i.Description + '|' +
ic.Description + '|' +
cc.Description + '|' +
ib.Description) > 0
Realize that this will cause a full table scan of all four tables, so it will be slow if these tables are large. But given what you are trying to do, the only alternative would be to implement full text indices on the database...
Also, if it is possiblke that one of these tables does not contain a matching row for yr join condition, you should make all the joins outer joins, and use IsNull()
on all the column references...
Select i.ItemID
From Inventory.Item i
Left Join Inventory.Category ic
On ic.ItemID = i.ItemID
Left Join Category.Category cc
On cat.CategoryID = ic.CategoryID
Left Join Inventory.Brand ib
On ib.BrandID = i.BrandID
Where CharIndex(@Term,
i.Description + '|' +
IsNull(ic.Description, '') + '|' +
IsNull(cc.Description, '') + '|' +
IsNull(ib.Description, '')) > 0
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