# WHERE

The `WHERE` clause selects the input rows used by a query. A row is retained only when its condition is SQL true. False and `NULL` results are excluded.

`WHERE` is evaluated before grouping. To filter an aggregate result, use [`HAVING`](https://coordinatordb.com/docs/reference/statements/select/having).

## Syntax

```text
SELECT expressions
FROM source
WHERE condition
```

Combine conditions with `AND`, `OR` and `NOT`. Parentheses make the intended precedence explicit. Comparisons can use columns, expressions, parameters and subqueries.

## Examples

### Selecting matching orders

```sql
CREATE TABLE orders (id INTEGER, status TEXT, amount INTEGER);
INSERT INTO orders VALUES (1, 'paid', 100), (2, 'pending', 200), (3, 'paid', 40);
```

```sql
SELECT id, amount
FROM orders
WHERE status = 'paid' AND amount >= 50
ORDER BY id
FORMAT csv;
```

```text
1,100
```

### Testing missing values

`value = NULL` does not select missing values. Use `IS NULL`:

```sql
CREATE TABLE contacts (id INTEGER, email TEXT);
INSERT INTO contacts VALUES (1, 'ada@example.org'), (2, NULL);
```

```sql
SELECT id
FROM contacts
WHERE email IS NULL
FORMAT csv;
```

```text
2
```

See [`IN`](https://coordinatordb.com/docs/reference/statements/in) for membership tests and [comparison functions](https://coordinatordb.com/docs/reference/functions/regular-functions/comparison-functions) for related predicates.