Cookbook

Code Examples

Code examples on how to use the PartiQL library inside your code base. Please consult the kdoc for more information on individual classes and interfaces.

Java

IonSystem ion = IonSystemBuilder.standard().build();

String myTable = "[{name: \"zoe\",  age: 12},\n" +
        "{name: \"jan\",  age: 20},\n" +
        "{name: \"bill\", age: 19},\n" +
        "{name: \"lisa\", age: 10},\n" +
        "{name: \"tim\",  age: 30},\n" +
        "{name: \"mary\", age: 19}]";

CompilerPipeline pipeline = CompilerPipeline.standard(ion);

Expression expression = pipeline.compile("SELECT t.name FROM myTable AS t WHERE t.age > 20");

ExprValue boundValue = pipeline.getValueFactory().newFromIonValue(ion.singleValue(myTable));
Bindings myGlobalBindings = bindingName -> {
    ExprValue exprValue;
    if (BindingCase.SENSITIVE.equals(bindingName.getBindingCase())) {
        exprValue = "myTable".equals(bindingName.getName()) ? boundValue : null;
    } else {
        exprValue = "myTable".equalsIgnoreCase(bindingName.getName()) ? boundValue : null;
    }
    
    return exprValue;
};

EvaluationSession session = EvaluationSession.builder()
    .globals(myGlobalBindings)
    .build();

ExprValue exprValue = expression.eval(session);
IonValue queryResultAsIon = exprValue.getIonValue();

Kotlin

val ion = IonSystemBuilder.standard().build()

val myTable = """[
        {name: "zoe",  age: 12},
        {name: "jan",  age: 20},
        {name: "bill", age: 19},
        {name: "lisa", age: 10},
        {name: "tim",  age: 30},
        {name: "mary", age: 19}]
    """

val pipeline = CompilerPipeline.standard(ion)
val expression = pipeline.compile("SELECT t.name FROM myTable AS t WHERE t.age > 20")

val boundValue = pipeline.valueFactory.newFromIonValue(ion.singleValue(myTable))
val session = EvaluationSession.builder()
    .globals(Bindings.buildLazyBindings { addBinding("myTable") { boundValue } })
    .build()

val exprValue = expression.eval(session)
val queryResultAsIon = exprValue.toIonValue(ion)

Data Types

Decimal

PartiQL decimals are based on [Ion decimals] from the Ion Specification[@IonSpec] but with a maximum precision of 38 digits, numbers outside this precision range will be rounded using a round [half even strategy]. Examples:

1.00000000000000000000000000000000000000000001 -> 1.0000000000000000000000000000000000000
1.99999999999999999999999999999999999999999999 -> 2.0000000000000000000000000000000000000