Easy approach using 'HAVING' | 'GROUP BY'
\n# Code\n\n/* Write your T-SQL query statement below */\n\nSELECT customer_id\nFROM Customer C \nGROUP BY customer_id\nHAVING count(DISTINCT C.product_key) = (
\n# Code\n```\n/* Write your T-SQL query statement below */\n\nSELECT customer_id\nFROM Customer C \nGROUP BY customer_id\nHAVING count(DISTINCT C.product_key) = (SELECT count(product_key) FROM Product);\n```
['MS SQL Server']