How do I parse JSON in MySQL vs PostgreSQL?

In MySQL, use JSON_EXTRACT(data, "$.key") or the inline ->> operator (e.g. data->>"$.user.name"). In PostgreSQL, use the text extraction operator ->> (e.g. data->'user'->>'name') or jsonb_extract_path_text().

How do I query rows where a JSON property matches a value in WHERE clauses?

In MySQL: WHERE data->>"$.status" = "active". In PostgreSQL: WHERE data->>'status' = 'active'. In SQL Server: WHERE JSON_VALUE(data, "$.status") = "active". In SQLite: WHERE json_extract(data, "$.status") = "active".

How do I unnest a JSON array of objects into multiple SQL rows?

Use MySQL JSON_TABLE(), PostgreSQL jsonb_to_recordset() or jsonb_array_elements(), SQL Server OPENJSON() with WITH clause, or SQLite json_each().

Parse JSON in SQL Query Generator: MySQL, PostgreSQL, SQLite & T-SQL

Querying Unstructured JSON in Relational Databases

Storing JSON payloads inside relational columns allows flexible schemas without running separate NoSQL document stores (like MongoDB). However, querying, filtering, and indexing JSON columns requires dialect-specific functions that differ dramatically across database engines.

Dialect Comparison for JSON Parsing

MySQL & MariaDB: Supports JSON_EXTRACT(col, '$.path'), the shorthand extraction operator -> (quoted) and ->> (unquoted text), plus JSON_TABLE() for tabular projections.
PostgreSQL: Supports native jsonb datatype with operators -> (returns JSON) and ->> (returns text), path traversal #>> '{a,b}', and GIN indexing for high-speed indexing.
SQLite: Uses built-in json_extract(col, '$.path') and col ->> '$.path' (since SQLite 3.38.0).
Microsoft SQL Server: Uses JSON_VALUE(col, '$.path') for scalar values, JSON_QUERY() for arrays/objects, and OPENJSON().

Frequently Asked Questions

Can I index JSON fields in SQL for fast performance?

Yes! In MySQL, create a generated virtual column (e.g. ALTER TABLE users ADD email VARCHAR(255) AS (metadata->>"$.profile.email")) and create a normal index on that virtual column. In PostgreSQL, create a direct expression index: CREATE INDEX idx_user_email ON users ((metadata->>'email')).

Can I test these queries immediately?

Yes, click "Run in Sandbox" to launch our WebAssembly SQLite compiler and test SQLite JSON functions directly in your browser.