SQL - Set Operations
How can you combine two SELECT queries in SQL to include all rows from both queries, including duplicates?
How can you combine two SELECT queries in SQL to include all rows from both queries, including duplicates?
hard📝 Application Q9 of 15
Step-by-Step Solution
Solution:
Step 1: Understand set operations
UNION removes duplicates, UNION ALL keeps duplicates.Step 2: Identify correct operation
To keep all rows including duplicates, UNION ALL is used.Final Answer:
Use UNION ALL to combine the queries -> Option CQuick Check:
UNION ALL preserves duplicates, unlike UNION [OK]
Quick Trick: UNION ALL keeps duplicates, UNION removes them [OK]
Common Mistakes:
MISTAKES- Using UNION instead of UNION ALL
- Confusing INTERSECT with UNION ALL
- Using EXCEPT which excludes rows
Master "Set Operations" in SQL
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