# Java SDK Query Predicate builders

Create readable and maintainable Query Predicates using the Java SDK.

The [Java SDK Query Predicate builder](https://github.com/commercetools/commercetools-sdk-java-v2/tree/main/commercetools/commercetools-sdk-java-api/src/main/java/com/commercetools/api/predicates) offers a fluent, type-safe interface for building [Query Predicates](/api/predicates/query.md).

Alternatively, you can use query predicates directly as strings with [input variables](/api/predicates/query.md#input-variable-examples). Input variables allow you to parameterize predicates and avoid string concatenation:

```java title="Use input variables with Query Predicates"
// Using an input variable for a single value
CustomerPagedQueryResponse response = httpApiRoot
  .customers()
  .get()
  .withPredicateVar("name", "John")
  .withWhere("firstName = :name")
  .executeBlocking()
  .getBody();

// Using an input variable for an array of values
CartPagedQueryResponse cartResponse = httpApiRoot
  .carts()
  .get()
  .addPredicateVar("statuses", Arrays.asList("Open", "Merged"))
  .withWhere("cartState in :statuses")
  .executeBlocking()
  .getBody();
```

## Example usage

The following examples demonstrate how to use the Query Predicate builder for different scenarios. More examples can be found [here](https://github.com/commercetools/commercetools-sdk-java-v2/tree/main/commercetools/commercetools-sdk-java-api/src/test/java/com/commercetools/api/predicates/query).

```java title="Build a Query Predicate for Customers"
import static com.commercetools.api.predicates.query.CustomerQueryBuilderDsl.*;

// Finds Customers called "John Doe"
String predicate = CustomerQueryBuilderDsl.of()
      .firstName().is("John")
      .and()
      .lastName().is("Doe")
      .build();
```

### Equality comparisons

```java title="Equality comparisons"
// Finds a Cart where the `id` is "abc"
CartQueryBuilderDsl.of().id().is("abc");

// Finds all Customers born on 12 October 2005
CustomerQueryBuilderDsl.of().dateOfBirth().is(LocalDate.parse("2005-10-12"));

// Finds all Tax Rates with an `amount` of 19%
TaxRateQueryBuilderDsl.of().amount().is(0.19);
```

### Logical operators

```java title="Logical operators"
// Finds Carts where the `id` is not "abc"
CartQueryBuilderDsl.of().id().is("abc").not();

// Finds Carts where the `id` is "abc" and `customerId` is "def"
CartQueryBuilderDsl.of().id().is("abc").and(p -> p.customerId().is("def"));


// Finds Carts where the `id` is "abc" or `customerId` is "def"
CartQueryBuilderDsl.of().id().is("abc").or(p -> p.customerId().is("def"));
```

### Range comparisons

```java title="Range comparisons"
// Finds Carts where `version` < 10
CartQueryBuilderDsl.of().version().isLessThan(10L);

// Finds Carts where `version` > 10
CartQueryBuilderDsl.of().version().isGreaterThan(10L);

// Finds all Tax Rates with an `amount` of less than 19%
TaxRateQueryBuilderDsl.of().amount().isLessThan(0.19);

// Finds all Customers born after 12 October 2005
CustomerQueryBuilderDsl.of().dateOfBirth().isGreaterThan(LocalDate.parse("2005-10-12"));
```

### Collection queries

```java title="Collection queries"
// Finds Carts where `key` is `foo` or `bar`
CartQueryBuilderDsl.of().key().isIn(Arrays.asList("foo", "bar"));

// Finds Tax Rates where the amount is 19% or 20%
TaxRateQueryBuilderDsl.of().amount().isIn(Arrays.asList(0.19, 0.20));
```

### Nested queries

```java title="Nested queries"
// Finds a Product where the current projection's English slug is "super-product" and the English name is "Super Product"
ProductQueryBuilderDsl.of()
  .masterData(m -> m.current(c -> c.slug(l -> l.with(Locale.ENGLISH).is("super-product"))
    .and(t -> t.name(l -> l.with(Locale.ENGLISH).is("Super Product")))));
```

### Special cases

```java title="Special cases"
// Finds Carts which have a `key`
CartQueryBuilderDsl.of().key().isDefined();

// Finds Carts which do not have a `key`
CartQueryBuilderDsl.of().key().isNotDefined();

// Finds Carts without Line Items
CartQueryBuilderDsl.of().lineItems().isEmpty();

// Finds Types where the `resourceTypeIds` contains `approval-flow`
TypeQueryBuilderDsl.of().resourceTypeIds().containsAnyVar("approval-flow");
```

## Related pages

- [Area overview page with navigation](/dev-tooling.md)
- [Previous page: Best practices](/dev-tooling/java-sdk-best-practices.md)