# Search the local database

Continuing with the `StructureRecord` class and `store` from the previous
step, the v2 search DSL keeps the v1 shape: bind a variable, add conditions,
declare outputs, and iterate.

```python
from httk.atomistic import StructureRecord

search = store.searcher()
structure = search.variable(StructureRecord)
search.add(structure.species_at_sites.has_any("O"))
search.output(structure, "structure")

for values, names in search:
    print("Found:", len(values[0].species_at_sites), "sites")
```

List fields have explicit set operations: `has_any`, `has_only`, and `is_in`.
References chain into automatic joins, and two variables of the same class form
a self-join.

See the complete query DSL example in the versioned *httk-data* documentation
listed by the {doc}`module directory <../modules>`.