[Solved] Identify the error in this query:SELECT a.id, b.name FROM tableA a INNER JOIN tableB b ON a.id == b.a_id; | PostgreSQL

PostgreSQL - Joins in PostgreSQL

Identify the error in this query:

SELECT a.id, b.name FROM tableA a INNER JOIN tableB b ON a.id == b.a_id;

AINNER JOIN requires USING clause, not ON

BMissing table alias for tableB

CSELECT clause must include all columns from both tables

DUsing '==' instead of '=' in ON clause

Step-by-Step Solution

Solution:

Step 1: Check ON clause syntax
SQL uses single '=' for comparison, '==' is invalid syntax.
Step 2: Verify other parts
Table aliases are correctly used, INNER JOIN supports ON clause, SELECT can specify columns.
Final Answer:
Using '==' instead of '=' in ON clause -> Option D
Quick Check:
ON clause uses '=' not '==' [OK]

Quick Trick: Use single '=' in ON clause for joins [OK]

Common Mistakes:

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