# json_object_agg_unique

Collect rows into a native JSON object.

**Syntax**

```text
json_object_agg_unique(key,value)
```

**Arguments**

Scalar non-NULL keys and native values. Retain SQL NULL values as JSON null. All keys, including skipped NULL-value keys, must be unique; duplicates raise DUPLICATE_JSON_KEY. Plain JSON preserves object input order and nested duplicates. Tuple values use named/fN fields. FILTER, DISTINCT, aggregate ordering, and ordinary windows apply.

**Returned value**

Native JSON. No input rows returns SQL NULL; rows containing only skipped SQL NULL values produce an empty container.

**Examples**

```sql
CREATE TABLE attributes (name TEXT, value INTEGER);
INSERT INTO attributes VALUES ('a',1),('b',NULL);
```

```sql
SELECT json_object_agg_unique(name,value) FROM attributes FORMAT csv;
```

```text
"{""a"":1,""b"":null}"
```