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* to you under the Apache License, Version 2.0 (the
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* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
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package com.datastax.oss.driver.api.querybuilder.relation;
import com.datastax.oss.driver.api.core.CqlIdentifier;
import com.datastax.oss.driver.api.core.cql.Statement;
import com.datastax.oss.driver.api.querybuilder.BuildableQuery;
import com.datastax.oss.driver.api.querybuilder.CqlSnippet;
import com.datastax.oss.driver.api.querybuilder.term.Term;
import com.datastax.oss.driver.internal.core.CqlIdentifiers;
import com.datastax.oss.driver.internal.querybuilder.relation.CustomIndexRelation;
import com.datastax.oss.driver.internal.querybuilder.relation.DefaultColumnComponentRelationBuilder;
import com.datastax.oss.driver.internal.querybuilder.relation.DefaultColumnRelationBuilder;
import com.datastax.oss.driver.internal.querybuilder.relation.DefaultMultiColumnRelationBuilder;
import com.datastax.oss.driver.internal.querybuilder.relation.DefaultTokenRelationBuilder;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.Arrays;
/**
* A relation in a WHERE clause.
*
* To build instances of this type, use the factory methods, such as {@link #column(String)
* column}, {@link #token(String...) token}, etc.
*
*
They are used as arguments to the {@link OngoingWhereClause#where(Iterable) where} method, for
* example:
*
*
{@code
* selectFrom("foo").all().where(Relation.column("k").isEqualTo(literal(1)))
* // SELECT * FROM foo WHERE k=1
* }
*
* There are also shortcuts in the fluent API when you build a statement, for example:
*
* {@code
* selectFrom("foo").all().whereColumn("k").isEqualTo(literal(1))
* // SELECT * FROM foo WHERE k=1
* }
*/
public interface Relation extends CqlSnippet {
/**
* Builds a relation testing a column.
*
* This must be chained with an operator call, for example:
*
*
{@code
* Relation r = Relation.column("k").isEqualTo(bindMarker());
* }
*/
@NonNull
static ColumnRelationBuilder column(@NonNull CqlIdentifier id) {
return new DefaultColumnRelationBuilder(id);
}
/** Shortcut for {@link #column(CqlIdentifier) column(CqlIdentifier.fromCql(name))} */
@NonNull
static ColumnRelationBuilder column(@NonNull String name) {
return column(CqlIdentifier.fromCql(name));
}
/** Builds a relation testing a value in a map (Cassandra 4 and above). */
@NonNull
static ColumnComponentRelationBuilder mapValue(
@NonNull CqlIdentifier columnId, @NonNull Term index) {
// The concept could easily be extended to list elements and tuple components, so use a generic
// name internally, we'll add other shortcuts if necessary.
return new DefaultColumnComponentRelationBuilder(columnId, index);
}
/**
* Shortcut for {@link #mapValue(CqlIdentifier, Term) mapValue(CqlIdentifier.fromCql(columnName),
* index)}
*/
@NonNull
static ColumnComponentRelationBuilder mapValue(
@NonNull String columnName, @NonNull Term index) {
return mapValue(CqlIdentifier.fromCql(columnName), index);
}
/** Builds a relation testing a token generated from a set of columns. */
@NonNull
static TokenRelationBuilder tokenFromIds(@NonNull Iterable identifiers) {
return new DefaultTokenRelationBuilder(identifiers);
}
/** Var-arg equivalent of {@link #tokenFromIds(Iterable)}. */
@NonNull
static TokenRelationBuilder token(@NonNull CqlIdentifier... identifiers) {
return tokenFromIds(Arrays.asList(identifiers));
}
/**
* Equivalent of {@link #tokenFromIds(Iterable)} with raw strings; the names are converted with
* {@link CqlIdentifier#fromCql(String)}.
*/
@NonNull
static TokenRelationBuilder token(@NonNull Iterable names) {
return tokenFromIds(CqlIdentifiers.wrap(names));
}
/** Var-arg equivalent of {@link #token(Iterable)}. */
@NonNull
static TokenRelationBuilder token(@NonNull String... names) {
return token(Arrays.asList(names));
}
/** Builds a multi-column relation, as in {@code WHERE (c1, c2, c3) IN ...}. */
@NonNull
static MultiColumnRelationBuilder columnIds(
@NonNull Iterable identifiers) {
return new DefaultMultiColumnRelationBuilder(identifiers);
}
/** Var-arg equivalent of {@link #columnIds(Iterable)}. */
@NonNull
static MultiColumnRelationBuilder columns(@NonNull CqlIdentifier... identifiers) {
return columnIds(Arrays.asList(identifiers));
}
/**
* Equivalent of {@link #columnIds(Iterable)} with raw strings; the names are converted with
* {@link CqlIdentifier#fromCql(String)}.
*/
@NonNull
static MultiColumnRelationBuilder columns(@NonNull Iterable names) {
return columnIds(CqlIdentifiers.wrap(names));
}
/** Var-arg equivalent of {@link #columns(Iterable)}. */
@NonNull
static MultiColumnRelationBuilder columns(@NonNull String... names) {
return columns(Arrays.asList(names));
}
/** Builds a relation on a custom index. */
@NonNull
static Relation customIndex(@NonNull CqlIdentifier indexId, @NonNull Term expression) {
return new CustomIndexRelation(indexId, expression);
}
/**
* Shortcut for {@link #customIndex(CqlIdentifier, Term)
* customIndex(CqlIdentifier.fromCql(indexName), expression)}
*/
@NonNull
static Relation customIndex(@NonNull String indexName, @NonNull Term expression) {
return customIndex(CqlIdentifier.fromCql(indexName), expression);
}
/**
* Whether this relation is idempotent.
*
* That is, whether it always selects the same rows when used multiple times. For example,
* {@code WHERE c=1} is idempotent, {@code WHERE c=now()} isn't.
*
*
This is used internally by the query builder to compute the {@link Statement#isIdempotent()}
* flag on the UPDATE and DELETE statements generated by {@link BuildableQuery#build()} (this is
* not relevant for SELECT statement, which are always idempotent). If a term is ambiguous (for
* example a raw snippet or a call to a user function in the right operands), the builder is
* pessimistic and assumes the term is not idempotent.
*/
boolean isIdempotent();
}