[Solved] Identify the error in this query:SELECT id FROM table1 UNION ALL table2; — Ans: Syntax error: second SELECT query missing | PostgreSQL

PostgreSQL - Set Operations and Advanced Queries

Identify the error in this query:
SELECT id FROM table1 UNION ALL table2;

AMissing SELECT keyword before second table

BSyntax error: second SELECT query missing

CUNION ALL cannot be used with tables

DNo error, query is valid

Step-by-Step Solution

Solution:

Step 1: Analyze UNION ALL syntax
UNION ALL requires two SELECT queries separated by UNION ALL.
Step 2: Check the query structure
The second SELECT keyword is missing before table2, causing syntax error.
Final Answer:
Syntax error: second SELECT query missing -> Option B
Quick Check:
UNION ALL needs two SELECTs [OK]

Quick Trick: Always write SELECT before each query in UNION ALL [OK]

Common Mistakes:

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Identify the error in this query: