com.datastax.oss.driver.api.querybuilder.term.Term Maven / Gradle / Ivy
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*
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package com.datastax.oss.driver.api.querybuilder.term;
import com.datastax.oss.driver.api.core.CqlIdentifier;
import com.datastax.oss.driver.api.core.cql.Statement;
import com.datastax.oss.driver.api.core.type.DataType;
import com.datastax.oss.driver.api.querybuilder.BuildableQuery;
import com.datastax.oss.driver.api.querybuilder.CqlSnippet;
import com.datastax.oss.driver.api.querybuilder.QueryBuilder;
import com.datastax.oss.driver.api.querybuilder.relation.Relation;
import com.datastax.oss.driver.api.querybuilder.select.OngoingSelection;
import com.datastax.oss.driver.api.querybuilder.select.Selector;
/**
* A simple expression that doesn't reference columns.
*
* It is used as an argument to certain {@linkplain Selector selectors} (for example the indices
* in a {@linkplain OngoingSelection#range(Selector, Term, Term) range}), or as the right operand of
* {@linkplain Relation relations}.
*
*
To create a term, call one of the static factory methods in {@link QueryBuilder}:
*
*
* - {@link QueryBuilder#literal(Object) literal()} to inline a Java object into the query
* string;
*
- {@link QueryBuilder#function(CqlIdentifier, CqlIdentifier, Iterable) function()} to invoke
* a built-in or user-defined function;
*
- an arithmetic operator combining other terms: {@link QueryBuilder#add(Term, Term) add()},
* {@link QueryBuilder#subtract(Term, Term) subtract()}, {@link QueryBuilder#negate(Term)
* negate()}, {@link QueryBuilder#multiply(Term, Term) multiply()}, {@link
* QueryBuilder#divide(Term, Term) divide()} or {@link QueryBuilder#remainder(Term, Term)
* remainder()};
*
- {@link QueryBuilder#typeHint(Term, DataType) typeHint()} to coerce another term to a
* particular CQL type;
*
- {@link QueryBuilder#raw(String) raw()} for a raw CQL snippet.
*
*
* Note that some of these methods have multiple overloads.
*/
public interface Term extends CqlSnippet {
/**
* Whether the term is idempotent.
*
* That is, whether it always produces the same result when used multiple times. For example,
* the literal {@code 1} is idempotent, the function call {@code now()} isn't.
*
*
This is used internally by the query builder to compute the {@link Statement#isIdempotent()}
* flag on the statements generated by {@link BuildableQuery#build()}. If a term is ambiguous (for
* example a raw snippet or a call to a user function), the builder is pessimistic and assumes the
* term is not idempotent.
*/
boolean isIdempotent();
}