[Solved] What happens if you insert duplicate keys in a JSONB column in PostgreSQL? — Ans: The last key-value pair overwrites previous duplicates. | PostgreSQL

PostgreSQL - JSON and JSONB

What happens if you insert duplicate keys in a JSONB column in PostgreSQL?

AOnly the first key-value pair is stored; duplicates ignored.

BPostgreSQL throws an error and rejects the insert.

CAll duplicate keys are stored as an array.

DThe last key-value pair overwrites previous duplicates.

Step-by-Step Solution

Solution:

Step 1: Understand JSONB duplicate key behavior
JSONB normalizes data and keeps only the last occurrence of duplicate keys.
Step 2: Confirm no error or array storage
PostgreSQL does not error or store duplicates as arrays in JSONB.
Final Answer:
The last key-value pair overwrites previous duplicates. -> Option D
Quick Check:
JSONB duplicates keep last key-value [OK]

Quick Trick: JSONB keeps last duplicate key, overwriting earlier ones [OK]

Common Mistakes:

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What happens if you insert duplicate keys in a JSONB column in PostgreSQL?