From 44a8fccc86ba364fa1d4c4b631014c0c8376cf7a Mon Sep 17 00:00:00 2001 From: Michael Bayne Date: Tue, 7 Dec 2010 21:05:42 +0000 Subject: [PATCH] Added FluentRepository, which provides helper methods for creating all of the various query clauses. Something like this: MaxPointsRecord max = load(MaxPointsRecord.class, new FromOverride(DailyScoreRecord.class), new Where(DailyScoreRecord.KEY.eq(key))); List top = findAll(DailyLeaderRecord.class, new FromOverride(DailyScoreRecord.class), DailyScoreRecord.KNIGHT_ID.join(KnightRecord.KNIGHT_ID), new Where(Ops.and(DailyScoreRecord.KEY.eq(key), DailyScoreRecord.POINTS.eq(max.maxPoints)))); becomes this: MaxPointsRecord max = load(MaxPointsRecord.class, from(DailyScoreRecord.class), where(DailyScoreRecord.KEY.eq(key))); List top = findAll(DailyLeaderRecord.class, from(DailyScoreRecord.class), join(DailyScoreRecord.KNIGHT_ID, KnightRecord.KNIGHT_ID), where(DailyScoreRecord.KEY.eq(key), DailyScoreRecord.POINTS.eq(max.maxPoints))); and the imports for Where and FromOverride go away. It's a modest improvement in readability. Both COL.join(OCOL) and join(COL, OCOL) are supported; one can choose based on the aesthetic demands of an individual query. --- .../com/samskivert/depot/CountRecord.java | 5 +- .../samskivert/depot/FluentRepository.java | 150 ++++++++++++++++++ .../com/samskivert/depot/TestRepository.java | 6 +- 3 files changed, 154 insertions(+), 7 deletions(-) create mode 100644 src/main/java/com/samskivert/depot/FluentRepository.java diff --git a/src/main/java/com/samskivert/depot/CountRecord.java b/src/main/java/com/samskivert/depot/CountRecord.java index 2a2a036..2f568ea 100644 --- a/src/main/java/com/samskivert/depot/CountRecord.java +++ b/src/main/java/com/samskivert/depot/CountRecord.java @@ -27,9 +27,8 @@ import com.samskivert.depot.expression.ColumnExp; /** * Handy record for computing the count of something. For example: * 
- * return load(CountRecord.class,
- *     new FromOverride(ForumThreadRecord.class),
- *     new Where(ForumThreadRecord.GROUP_ID.eq(groupId)).count;
+ * return load(CountRecord.class, from(ForumThreadRecord.class),
+ *             where(ForumThreadRecord.GROUP_ID.eq(groupId)).count;
  *
*/ @Computed @Entity diff --git a/src/main/java/com/samskivert/depot/FluentRepository.java b/src/main/java/com/samskivert/depot/FluentRepository.java new file mode 100644 index 0000000..e5d03f1 --- /dev/null +++ b/src/main/java/com/samskivert/depot/FluentRepository.java @@ -0,0 +1,150 @@ +// +// $Id$ +// +// Depot library - a Java relational persistence library +// Copyright (C) 2006-2010 Michael Bayne and Pär Winzell +// +// This library is free software; you can redistribute it and/or modify it +// under the terms of the GNU Lesser General Public License as published +// by the Free Software Foundation; either version 2.1 of the License, or +// (at your option) any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public +// License along with this library; if not, write to the Free Software +// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + +package com.samskivert.depot; + +import com.samskivert.depot.clause.ForUpdate; +import com.samskivert.depot.clause.FromOverride; +import com.samskivert.depot.clause.GroupBy; +import com.samskivert.depot.clause.Join; +import com.samskivert.depot.clause.Limit; +import com.samskivert.depot.clause.OrderBy; +import com.samskivert.depot.clause.Where; +import com.samskivert.depot.expression.ColumnExp; +import com.samskivert.depot.expression.SQLExpression; + +/** + * Provides a variety of helper methods for constructing queries more concisely (and in some case + * using a more fluent style). + */ +public abstract class FluentRepository extends DepotRepository +{ + protected FluentRepository (PersistenceContext context) + { + super(context); + } + + /** + * Returns a {@link Where} clause that ANDs together all of the supplied expressions. + */ + protected static Where where (SQLExpression... exprs) + { + switch (exprs.length) { + case 0: + throw new IllegalArgumentException("Must supply at least one expression."); + case 1: + return new Where(exprs[0]); + default: + return new Where(Ops.and(exprs)); + } + } + + /** + * Returns a {@link Where} clause that selects rows where the supplied column equals the + * supplied value. + */ + protected static Where where (ColumnExp column, Comparable value) + { + return new Where(column, value); + } + + /** + * Returns a {@link Where} clause that selects rows where both supplied columns equal both + * supplied values. + */ + protected static Where where (ColumnExp index1, Comparable value1, + ColumnExp index2, Comparable value2) + { + return new Where(index1, value1, index2, value2); + } + + /** + * Returns a {@link Join} clause configured with the supplied left and right columns. + */ + protected static Join join (ColumnExp left, ColumnExp right) + { + return new Join(left, right); + } + + /** + * Returns a {@link GroupBy} clause on the supplied group expressions. + */ + protected static GroupBy groupBy (SQLExpression... exprs) + { + return new GroupBy(exprs); + } + + /** + * Returns an {@link OrderBy} clause configured to randomly order the results. + */ + protected static OrderBy random () + { + return OrderBy.random(); + } + + /** + * Returns an {@link OrderBy} clause that ascends on the supplied expression. + */ + protected static OrderBy ascending (SQLExpression value) + { + return OrderBy.ascending(value); + } + + /** + * Returns an {@link OrderBy} clause that descends on the supplied expression. + */ + protected static OrderBy descending (SQLExpression value) + { + return OrderBy.descending(value); + } + + /** + * Returns a {@link Limit} clause configured with the supplied offset and count. + */ + protected static Limit limit (int offset, int count) + { + return new Limit(offset, count); + } + + /** + * Returns a {@link FromOverride} clause configured with the supplied override class. + */ + protected static FromOverride from (Class fromClass) + { + return new FromOverride(fromClass); + } + + /** + * Returns a {@link FromOverride} clause configured with the supplied override classes. + */ + protected static FromOverride from (Class fromClass1, + Class fromClass2) + { + return new FromOverride(fromClass1, fromClass2); + } + + /** + * Returns a {@link ForUpdate} clause which marks this query as selecting for update. + */ + protected static ForUpdate forUpdate () + { + return new ForUpdate(); + } +} diff --git a/src/test/java/com/samskivert/depot/TestRepository.java b/src/test/java/com/samskivert/depot/TestRepository.java index b325a97..0a787bd 100644 --- a/src/test/java/com/samskivert/depot/TestRepository.java +++ b/src/test/java/com/samskivert/depot/TestRepository.java @@ -23,12 +23,10 @@ package com.samskivert.depot; import java.util.List; import java.util.Set; -import com.samskivert.depot.clause.Where; - /** * A test tool for the Depot repository services. */ -public class TestRepository extends DepotRepository +public class TestRepository extends FluentRepository { public TestRecord loadNoCache (int recordId) { @@ -47,7 +45,7 @@ public class TestRepository extends DepotRepository public List loadEnums (Set types) { - return findAll(EnumKeyRecord.class, new Where(EnumKeyRecord.TYPE.in(types))); + return findAll(EnumKeyRecord.class, where(EnumKeyRecord.TYPE.in(types))); } public void storeEnum (EnumKeyRecord record)