Magento SQLSTATE[22003]: Numeric value out of range: 1690 BIGINT UNSIGNED value is out of range in '(`DATABASE`.`q`.`items_count` - 1)'
First of all take the backup of Database and then follow the below steps
(1) Log in to PhpMyAdmin
(2) Select your Magento database
(3) Select the table sales_flat_quote
(4) Select the column ‘items_count’ and remove the ‘UNSIGNED’ attribute
(5) Save the table and re-index your catalog
After the completed to delete products, Re-assigned the ‘UNSIGNED’ value and Re-index the catalog.