declare @Description varchar(50) = "textbox_search.Text.Trim()"
SELECT IT.tr_id AS [Tr Id], IT.tr_date AS [Tr Date], IT.tr_type AS [Tr Type]
, IT.tr_no AS [Tr No], IT.item_id AS [Item Id], IT.item_no AS [Item No]
, IT.item_des AS [Description], IT.item_unit AS [Item Unit], IT.sale_rate AS [Sales Rate]
, IT.pur_rate_on_sale AS [Pur Rate], IT.discount_amount AS [Discount]
, IT.tax_amount AS [Tax], IT.cr_qty AS [Qty], IT.acc_no AS [Account No]
, IT.item_location AS [Location]
, INV.invoice_no AS [Invoice No]
, INV.invoice_date AS [Invoice Date]
FROM tbl_items_trans IT
left join tbl_invoices INV on IT.invoice_no = INV.invoice_no
WHERE (IT.tr_type = 'SALE' AND IT.item_des LIKE '%' + @Description + '%' )