How can you store a JSON array in a PostgreSQL JSONB column and query the second element of the array?

hard📝 Application Q9 of 15

PostgreSQL - JSON and JSONB

AINSERT INTO data_table (json_col) VALUES ('[10, 20, 30]'); SELECT json_col->>2 FROM data_table;

BINSERT INTO data_table (json_col) VALUES ('{10, 20, 30}'); SELECT json_col->2 FROM data_table;

CINSERT INTO data_table (json_col) VALUES ('[10, 20, 30]'); SELECT json_col->1 FROM data_table;

DINSERT INTO data_table (json_col) VALUES ('(10, 20, 30)'); SELECT json_col->1 FROM data_table;

Step-by-Step Solution

Solution:

Step 1: Insert JSON array syntax
JSON arrays use square brackets []; INSERT INTO data_table (json_col) VALUES ('[10, 20, 30]'); SELECT json_col->1 FROM data_table; uses correct JSON array syntax.
Step 2: Query second element with zero-based index
JSON array indexing is zero-based; ->1 extracts second element as JSON.
Final Answer:
INSERT INTO data_table (json_col) VALUES ('[10, 20, 30]'); SELECT json_col->1 FROM data_table; -> Option C
Quick Check:
JSON arrays use [] and zero-based indexing [OK]

Quick Trick: JSON arrays use zero-based index with -> operator [OK]

Common Mistakes:

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