This error occurs when accessing a non-existent field in JSON data with strict mode enabled. Switch to lax mode or use error handling clauses to suppress or handle missing JSON members gracefully.
PostgreSQL raises this error when your SQL/JSON path expression tries to access a non-existent member (field) of an object or element of an array in strict mode. In PostgreSQL's JSON path system, accessing missing data is considered a "structural error". By default, PostgreSQL uses lax mode which suppresses these errors and returns empty results, but strict mode will raise an exception. This typically occurs when your JSON data structure doesn't match what your query expects—for example, trying to access a field that doesn't exist in all objects, or accessing an array element beyond the array bounds.
By default, PostgreSQL uses lax mode which implicitly suppresses structural errors. If you're explicitly using strict mode, remove it:
-- BEFORE (strict mode - fails on missing fields)
SELECT jsonb_path_query(data, 'strict $.user.email') FROM logs;
-- AFTER (lax mode - returns empty on missing fields)
SELECT jsonb_path_query(data, 'lax $.user.email') FROM logs;Lax mode automatically adapts the query to handle missing data by returning empty results instead of raising an error.
Add error handling to your SQL/JSON path expression with the ON ERROR clause:
-- Return null if member not found
SELECT jsonb_path_query(data, '$ ? (@.status exists) | .status' NULL ON ERROR) FROM logs;
-- Return a default value
SELECT jsonb_path_query_first(data, '$.user.email DEFAULT \"[email protected]\"' NULL ON ERROR) FROM users;The @? and @@ operators automatically suppress structural errors and work in lax mode:
-- Check if field exists without throwing error
SELECT * FROM logs WHERE data @? '$.user.email';
-- Match with error suppression
SELECT * FROM users WHERE data @@ '$.status == \"active\"';These operators return true/false instead of raising errors when members are missing.
For simple field access, use the standard ->> or -> operators which return NULL instead of failing:
-- Standard accessor returns NULL for missing fields (no error)
SELECT COALESCE(data->'user'->>'email', '[email protected]') FROM logs;
-- Compare with jsonpath_query which needs error handling
SELECT jsonb_path_query_first(data, '$.user.email', NULL, silent => true) FROM logs;The standard ->> operator is the safest for simple member access.
Ensure consistency in your JSON data by adding constraints or normalizing data on insert:
-- Add check constraint to enforce minimum structure
ALTER TABLE users ADD CONSTRAINT valid_json_structure
CHECK (jsonb_typeof(data) = 'object' AND data ? 'email');
-- Normalize incomplete JSON when inserting
INSERT INTO logs (data) VALUES (
jsonb_set(
jsonb_build_object(),
'{user,email}',
''"[email protected]"'::jsonb
)
);This prevents mismatched data structures from causing errors in queries.
PostgreSQL has two modes for handling missing JSON members: lax mode (default) suppresses structural errors by returning empty results, and strict mode raises errors. The @? and @@ operators work exclusively in lax mode and suppress errors like missing object fields, array bounds, type mismatches, and numeric errors. When using jsonb_path functions, you can pass a silent => true parameter to achieve the same error suppression. For complex JSON queries, consider using CASE statements or subqueries to validate structure before accessing deeply nested fields. If working with inconsistent JSON schemas across multiple rows, use CASE expressions with ->> operators as a fallback pattern.
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