From 9db1cb40b66d9cbbd092a8aefdf25f3e3da00e1e Mon Sep 17 00:00:00 2001 From: Lukas Eder Date: Mon, 18 Aug 2014 10:14:06 +0200 Subject: [PATCH] [#1410] Add support for the Postgres "DISTINCT ON" clause --- .../test/java/org/jooq/test/PostgresTest.java | 21 +++ .../java/org/jooq/SelectDistinctOnStep.java | 124 ++++++++++++++++++ jOOQ/src/main/java/org/jooq/SelectQuery.java | 16 +++ .../main/java/org/jooq/SelectSelectStep.java | 2 +- .../main/java/org/jooq/impl/SelectImpl.java | 23 ++++ .../java/org/jooq/impl/SelectQueryImpl.java | 17 ++- 6 files changed, 201 insertions(+), 2 deletions(-) create mode 100644 jOOQ/src/main/java/org/jooq/SelectDistinctOnStep.java diff --git a/jOOQ-test/src/test/java/org/jooq/test/PostgresTest.java b/jOOQ-test/src/test/java/org/jooq/test/PostgresTest.java index 30403a2158..8bea32b7af 100644 --- a/jOOQ-test/src/test/java/org/jooq/test/PostgresTest.java +++ b/jOOQ-test/src/test/java/org/jooq/test/PostgresTest.java @@ -1388,4 +1388,25 @@ public class PostgresTest extends jOOQAbstractTest< assertEquals(4, (int) record.value3()); assertEquals(2, (int) record.value4()); } + + @Test + public void testPostgresDistinctOnTest() { + Result> r1 = + create().selectDistinct(T_BOOK.ID, T_BOOK.AUTHOR_ID) + .on(T_BOOK.AUTHOR_ID) + .from(T_BOOK) + .orderBy(T_BOOK.AUTHOR_ID) + .fetch(); + + Result> r2 = + create().select(T_BOOK.ID, T_BOOK.AUTHOR_ID) + .distinctOn(T_BOOK.AUTHOR_ID) + .from(T_BOOK) + .orderBy(T_BOOK.AUTHOR_ID) + .fetch(); + + assertEquals(r1, r2); + assertEquals(asList(1, 3), r1.getValues(T_BOOK.ID)); + assertEquals(asList(1, 2), r1.getValues(T_BOOK.AUTHOR_ID)); + } } diff --git a/jOOQ/src/main/java/org/jooq/SelectDistinctOnStep.java b/jOOQ/src/main/java/org/jooq/SelectDistinctOnStep.java new file mode 100644 index 0000000000..9f85fe0ac3 --- /dev/null +++ b/jOOQ/src/main/java/org/jooq/SelectDistinctOnStep.java @@ -0,0 +1,124 @@ +/** + * Copyright (c) 2009-2014, Data Geekery GmbH (http://www.datageekery.com) + * All rights reserved. + * + * This work is dual-licensed + * - under the Apache Software License 2.0 (the "ASL") + * - under the jOOQ License and Maintenance Agreement (the "jOOQ License") + * ============================================================================= + * You may choose which license applies to you: + * + * - If you're using this work with Open Source databases, you may choose + * either ASL or jOOQ License. + * - If you're using this work with at least one commercial database, you must + * choose jOOQ License + * + * For more information, please visit http://www.jooq.org/licenses + * + * Apache Software License 2.0: + * ----------------------------------------------------------------------------- + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * jOOQ License and Maintenance Agreement: + * ----------------------------------------------------------------------------- + * Data Geekery grants the Customer the non-exclusive, timely limited and + * non-transferable license to install and use the Software under the terms of + * the jOOQ License and Maintenance Agreement. + * + * This library is distributed with a LIMITED WARRANTY. See the jOOQ License + * and Maintenance Agreement for more details: http://www.jooq.org/licensing + */ +package org.jooq; + +import static org.jooq.SQLDialect.POSTGRES; + +import java.util.Collection; + +/** + * This type is used for the {@link Select}'s DSL API when selecting generic + * {@link Record} types. + *

+ * Example: 

+ * -- get all authors' first and last names, and the number
+ * -- of books they've written in German, if they have written
+ * -- more than five books in German in the last three years
+ * -- (from 2011), and sort those authors by last names
+ * -- limiting results to the second and third row
+ *
+ *   SELECT T_AUTHOR.FIRST_NAME, T_AUTHOR.LAST_NAME, COUNT(*)
+ *     FROM T_AUTHOR
+ *     JOIN T_BOOK ON T_AUTHOR.ID = T_BOOK.AUTHOR_ID
+ *    WHERE T_BOOK.LANGUAGE = 'DE'
+ *      AND T_BOOK.PUBLISHED > '2008-01-01'
+ * GROUP BY T_AUTHOR.FIRST_NAME, T_AUTHOR.LAST_NAME
+ *   HAVING COUNT(*) > 5
+ * ORDER BY T_AUTHOR.LAST_NAME ASC NULLS FIRST
+ *    LIMIT 2
+ *   OFFSET 1
+ *      FOR UPDATE
+ *       OF FIRST_NAME, LAST_NAME
+ *       NO WAIT
+ *
Its equivalent in jOOQ 
+ * create.select(TAuthor.FIRST_NAME, TAuthor.LAST_NAME, create.count())
+ *       .from(T_AUTHOR)
+ *       .join(T_BOOK).on(TBook.AUTHOR_ID.equal(TAuthor.ID))
+ *       .where(TBook.LANGUAGE.equal("DE"))
+ *       .and(TBook.PUBLISHED.greaterThan(parseDate('2008-01-01')))
+ *       .groupBy(TAuthor.FIRST_NAME, TAuthor.LAST_NAME)
+ *       .having(create.count().greaterThan(5))
+ *       .orderBy(TAuthor.LAST_NAME.asc().nullsFirst())
+ *       .limit(2)
+ *       .offset(1)
+ *       .forUpdate()
+ *       .of(TAuthor.FIRST_NAME, TAuthor.LAST_NAME)
+ *       .noWait();
+ *
Refer to the manual for more details + * + * @author Lukas Eder + */ +public interface SelectDistinctOnStep extends SelectIntoStep { + + /** + * Add the PostgreSQL-specific ON(...) clause to a + * SELECT DISTINCT ON (...) statement. + *

+ * This implicitly enforces the DISTINCT clause, no matter if + * it is added explicitly via the jOOQ API. + */ + @Support({ POSTGRES }) + SelectIntoStep on(Field... fields); + + /** + * Add the PostgreSQL-specific ON(...) clause to a + * SELECT DISTINCT ON (...) statement. + *

+ * This implicitly enforces the DISTINCT clause, no matter if + * it is added explicitly via the jOOQ API. + */ + @Support({ POSTGRES }) + SelectIntoStep on(Collection> fields); + + /** + * Add the PostgreSQL-specific ON(...) clause to a + * SELECT DISTINCT ON (...) statement. + */ + @Support({ POSTGRES }) + SelectIntoStep distinctOn(Field... fields); + + /** + * Add the PostgreSQL-specific ON(...) clause to a + * SELECT DISTINCT ON (...) statement. + */ + @Support({ POSTGRES }) + SelectIntoStep distinctOn(Collection> fields); +} diff --git a/jOOQ/src/main/java/org/jooq/SelectQuery.java b/jOOQ/src/main/java/org/jooq/SelectQuery.java index d2194c7f0d..cb19392d80 100644 --- a/jOOQ/src/main/java/org/jooq/SelectQuery.java +++ b/jOOQ/src/main/java/org/jooq/SelectQuery.java @@ -95,6 +95,22 @@ public interface SelectQuery extends Select, ConditionProvi @Support void setDistinct(boolean distinct); + /** + * Add a PostgreSQL-specific DISTINCT ON (fields...) clause. + *

+ * This also sets the distinct flag to true + */ + @Support({ POSTGRES }) + void addDistinctOn(Field... fields); + + /** + * Add a PostgreSQL-specific DISTINCT ON (fields...) clause. + *

+ * This also sets the distinct flag to true + */ + @Support({ POSTGRES }) + void addDistinctOn(Collection> fields); + /** * Add INTO clause to the SELECT statement. */ diff --git a/jOOQ/src/main/java/org/jooq/SelectSelectStep.java b/jOOQ/src/main/java/org/jooq/SelectSelectStep.java index 902776e0bf..fb1179bd44 100644 --- a/jOOQ/src/main/java/org/jooq/SelectSelectStep.java +++ b/jOOQ/src/main/java/org/jooq/SelectSelectStep.java @@ -85,7 +85,7 @@ import java.util.Collection; * * @author Lukas Eder */ -public interface SelectSelectStep extends SelectIntoStep { +public interface SelectSelectStep extends SelectDistinctOnStep { /** * Add additional fields to the SELECT clause of this query diff --git a/jOOQ/src/main/java/org/jooq/impl/SelectImpl.java b/jOOQ/src/main/java/org/jooq/impl/SelectImpl.java index 5e78298054..2ebb8d32cd 100644 --- a/jOOQ/src/main/java/org/jooq/impl/SelectImpl.java +++ b/jOOQ/src/main/java/org/jooq/impl/SelectImpl.java @@ -77,6 +77,7 @@ import org.jooq.SelectConditionStep; import org.jooq.SelectConnectByConditionStep; import org.jooq.SelectForUpdateOfStep; import org.jooq.SelectHavingConditionStep; +import org.jooq.SelectIntoStep; import org.jooq.SelectJoinStep; import org.jooq.SelectOffsetStep; import org.jooq.SelectOnConditionStep; @@ -240,6 +241,28 @@ class SelectImpl on(Field... fields) { + return distinctOn(Arrays.asList(fields)); + } + + @Override + public final SelectIntoStep on(Collection> fields) { + return distinctOn(fields); + } + + @Override + public final SelectIntoStep distinctOn(Field... fields) { + getQuery().addDistinctOn(fields); + return this; + } + + @Override + public final SelectIntoStep distinctOn(Collection> fields) { + getQuery().addDistinctOn(fields); + return this; + } + @Override public final SelectImpl into(Table table) { getQuery().setInto(table); diff --git a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java index 5cd9a1f34c..afc6f965c8 100644 --- a/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java +++ b/jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java @@ -139,6 +139,7 @@ class SelectQueryImpl extends AbstractSelect implements Sel private String hint; private String option; private boolean distinct; + private final QueryPartList> distinctOn; private boolean forUpdate; private final QueryPartList> forUpdateOf; private final TableList forUpdateOfTables; @@ -177,6 +178,7 @@ class SelectQueryImpl extends AbstractSelect implements Sel this.with = with; this.distinct = distinct; + this.distinctOn = new QueryPartList>(); this.select = new SelectFieldList(); this.from = new TableList(); this.condition = new ConditionProviderImpl(); @@ -620,7 +622,10 @@ class SelectQueryImpl extends AbstractSelect implements Sel x xx [/pro] */ - if (distinct) { + if (!distinctOn.isEmpty()) { + context.keyword("distinct on").sql(" (").visit(distinctOn).sql(") "); + } + else if (distinct) { context.keyword("distinct").sql(" "); } @@ -925,6 +930,16 @@ class SelectQueryImpl extends AbstractSelect implements Sel this.distinct = distinct; } + @Override + public final void addDistinctOn(Field... fields) { + addDistinctOn(Arrays.asList(fields)); + } + + @Override + public final void addDistinctOn(Collection> fields) { + this.distinctOn.addAll(fields); + } + @Override public final void setInto(Table into) { this.into = into;