Merge pull request #78 from jeffgbutler/limit-offset

Add Limit and Offset Support

Author: jeffgbutler

CHANGELOG.md

@@ -0,0 +1,10 @@
+# Change Log
+
+## Release 1.1.1 (Unreleased)
+
+### Added
+
+- Limit and offset support in the select statement
+
+
+## Release 1.1.0

pom.xml

@@ -60,6 +60,30 @@
         </plugin>
       </plugins>
     </pluginManagement>
+    <plugins>
+      <!-- Copy the changelog into the generated site -->
+      <plugin>
+        <artifactId>maven-resources-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>copy-changelog</id>
+            <phase>pre-site</phase>
+            <goals>
+              <goal>copy-resources</goal>
+            </goals>
+            <configuration>
+              <outputDirectory>${project.build.directory}/generated-site/markdown/docs</outputDirectory>
+              <resources>
+                <resource>
+                  <directory>${basedir}</directory>
+                  <include>CHANGELOG.md</include>
+                </resource>
+              </resources>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
   </build>
 
   <reporting>

src/main/java/org/mybatis/dynamic/sql/SqlColumn.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2018 the original author or authors.
+ *    Copyright 2016-2019 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.

src/main/java/org/mybatis/dynamic/sql/render/MyBatis3RenderingStrategy.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2018 the original author or authors.
+ *    Copyright 2016-2019 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -15,11 +15,13 @@
  */
 package org.mybatis.dynamic.sql.render;
 
+import java.util.Optional;
+
 import org.mybatis.dynamic.sql.BindableColumn;
 
 public class MyBatis3RenderingStrategy extends RenderingStrategy {
     @Override
-    public String getFormattedJdbcPlaceholder(BindableColumn<?> column, String prefix, String parameterName) {
+    public String getFormattedJdbcPlaceholder(Optional<BindableColumn<?>> column, String prefix, String parameterName) {
         return "#{" //$NON-NLS-1$
                 + prefix
                 + "." //$NON-NLS-1$
@@ -29,13 +31,17 @@ public String getFormattedJdbcPlaceholder(BindableColumn<?> column, String prefi
                 + "}"; //$NON-NLS-1$
     }
 
-    private String renderTypeHandler(BindableColumn<?> column) {
-        return column.typeHandler().map(th -> ",typeHandler=" + th) //$NON-NLS-1$
+    private String renderTypeHandler(Optional<BindableColumn<?>> column) {
+        return column
+                .flatMap(BindableColumn::typeHandler)
+                .map(th -> ",typeHandler=" + th) //$NON-NLS-1$
                 .orElse(""); //$NON-NLS-1$
     }
 
-    private String renderJdbcType(BindableColumn<?> column) {
-        return column.jdbcType().map(jt -> ",jdbcType=" + jt.getName()) //$NON-NLS-1$
+    private String renderJdbcType(Optional<BindableColumn<?>> column) {
+        return column
+                .flatMap(BindableColumn::jdbcType)
+                .map(jt -> ",jdbcType=" + jt.getName()) //$NON-NLS-1$
                 .orElse(""); //$NON-NLS-1$
     }
 }

src/main/java/org/mybatis/dynamic/sql/render/RenderingStrategy.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2017 the original author or authors.
+ *    Copyright 2016-2019 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -15,11 +15,22 @@
  */
 package org.mybatis.dynamic.sql.render;
 
+import java.util.Optional;
+
 import org.mybatis.dynamic.sql.BindableColumn;
 
 public abstract class RenderingStrategy {
     public static final RenderingStrategy MYBATIS3 = new MyBatis3RenderingStrategy();
     public static final RenderingStrategy SPRING_NAMED_PARAMETER = new SpringNamedParameterRenderingStrategy();
+    public static final String DEFAULT_PARAMETER_PREFIX = "parameters"; //$NON-NLS-1$
 
-    public abstract String getFormattedJdbcPlaceholder(BindableColumn<?> column, String prefix, String parameterName);
+    public String getFormattedJdbcPlaceholder(BindableColumn<?> column, String prefix, String parameterName) {
+        return getFormattedJdbcPlaceholder(Optional.of(column), prefix, parameterName);
+    }
+
+    public String getFormattedJdbcPlaceholder(String prefix, String parameterName) {
+        return getFormattedJdbcPlaceholder(Optional.empty(), prefix, parameterName);
+    }
+
+    public abstract String getFormattedJdbcPlaceholder(Optional<BindableColumn<?>> column, String prefix, String parameterName);
 }

src/main/java/org/mybatis/dynamic/sql/render/SpringNamedParameterRenderingStrategy.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2017 the original author or authors.
+ *    Copyright 2016-2019 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -15,13 +15,14 @@
  */
 package org.mybatis.dynamic.sql.render;
 
+import java.util.Optional;
+
 import org.mybatis.dynamic.sql.BindableColumn;
 
 public class SpringNamedParameterRenderingStrategy extends RenderingStrategy {
 
     @Override
-    public String getFormattedJdbcPlaceholder(BindableColumn<?> column, String prefix, String parameterName) {
+    public String getFormattedJdbcPlaceholder(Optional<BindableColumn<?>> column, String prefix, String parameterName) {
         return ":" + parameterName; //$NON-NLS-1$
     }
-
 }

src/main/java/org/mybatis/dynamic/sql/select/QueryExpressionDSL.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2018 the original author or authors.
+ *    Copyright 2016-2019 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -144,6 +144,16 @@ protected QueryExpressionModel buildModel() {
                 .build();
     }
 
+    public SelectDSL<R>.LimitFinisher limit(long limit) {
+        selectDSL.addQueryExpression(buildModel());
+        return selectDSL.limit(limit);
+    }
+
+    public SelectDSL<R>.OffsetFinisher offset(long offset) {
+        selectDSL.addQueryExpression(buildModel());
+        return selectDSL.offset(offset);
+    }
+
     public static class FromGatherer<R> {
         private FromGathererBuilder<R> builder;
         private Map<SqlTable, String> tableAliasMap = new HashMap<>();
@@ -234,6 +244,18 @@ public GroupByFinisher groupBy(BasicColumn...columns) {
             return new GroupByFinisher();
         }
 
+        public SelectDSL<R>.LimitFinisher limit(long limit) {
+            whereModel = buildWhereModel();
+            selectDSL.addQueryExpression(buildModel());
+            return selectDSL.limit(limit);
+        }
+        
+        public SelectDSL<R>.OffsetFinisher offset(long offset) {
+            whereModel = buildWhereModel();
+            selectDSL.addQueryExpression(buildModel());
+            return selectDSL.offset(offset);
+        }
+        
         @Override
         public R build() {
             whereModel = buildWhereModel();
@@ -384,6 +406,18 @@ public SelectDSL<R> orderBy(SortSpecification...columns) {
             selectDSL.setOrderByModel(OrderByModel.of(columns));
             return selectDSL;
         }
+
+        public SelectDSL<R>.LimitFinisher limit(long limit) {
+            joinModel = buildJoinModel();
+            selectDSL.addQueryExpression(buildModel());
+            return selectDSL.limit(limit);
+        }
+
+        public SelectDSL<R>.OffsetFinisher offset(long offset) {
+            joinModel = buildJoinModel();
+            selectDSL.addQueryExpression(buildModel());
+            return selectDSL.offset(offset);
+        }
     }
 
     public class GroupByFinisher implements Buildable<R> {
@@ -396,6 +430,14 @@ public SelectDSL<R> orderBy(SortSpecification...columns) {
         public R build() {
             return selectDSL.build();
         }
+
+        public SelectDSL<R>.LimitFinisher limit(long limit) {
+            return selectDSL.limit(limit);
+        }
+
+        public SelectDSL<R>.OffsetFinisher offset(long offset) {
+            return selectDSL.offset(offset);
+        }
     }
 
     public class UnionBuilder {

src/main/java/org/mybatis/dynamic/sql/select/SelectDSL.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2018 the original author or authors.
+ *    Copyright 2016-2019 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@
 import org.mybatis.dynamic.sql.select.QueryExpressionDSL.FromGatherer;
 import org.mybatis.dynamic.sql.select.QueryExpressionDSL.FromGathererBuilder;
 import org.mybatis.dynamic.sql.select.render.SelectStatementProvider;
+import org.mybatis.dynamic.sql.util.Buildable;
 
 /**
  * Implements a standard SQL dialect for building model classes.
@@ -32,11 +33,13 @@
  *
  * @param <R> the type of model produced by this builder
  */
-public class SelectDSL<R> {
+public class SelectDSL<R> implements Buildable<R> {
 
     private Function<SelectModel, R> adapterFunction;
     private List<QueryExpressionModel> queryExpressions = new ArrayList<>();    
     private OrderByModel orderByModel;
+    private Long limit;
+    private Long offset;
 
     private SelectDSL(Function<SelectModel, R> adapterFunction) {
         this.adapterFunction = Objects.requireNonNull(adapterFunction);
@@ -96,10 +99,41 @@ void setOrderByModel(OrderByModel orderByModel) {
         this.orderByModel = orderByModel;
     }
 
+    public LimitFinisher limit(long limit) {
+        this.limit = limit;
+        return new LimitFinisher();
+    }
+
+    public OffsetFinisher offset(long offset) {
+        this.offset = offset;
+        return new OffsetFinisher();
+    }
+
+    @Override
     public R build() {
         SelectModel selectModel = SelectModel.withQueryExpressions(queryExpressions)
                 .withOrderByModel(orderByModel)
+                .withLimit(limit)
+                .withOffset(offset)
                 .build();
         return adapterFunction.apply(selectModel);
     }
+    
+    public class LimitFinisher implements Buildable<R> {
+        public OffsetFinisher offset(int offset) {
+            return SelectDSL.this.offset(offset);
+        }
+        
+        @Override
+        public R build() {
+            return SelectDSL.this.build();
+        }
+    }
+
+    public class OffsetFinisher implements Buildable<R> {
+        @Override
+        public R build() {
+            return SelectDSL.this.build();
+        }
+    }
 }

src/main/java/org/mybatis/dynamic/sql/select/SelectModel.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2016-2018 the original author or authors.
+ *    Copyright 2016-2019 the original author or authors.
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -29,10 +29,14 @@
 public class SelectModel {
     private List<QueryExpressionModel> queryExpressions;
     private OrderByModel orderByModel;
+    private Long limit;
+    private Long offset;
 
     private SelectModel(Builder builder) {
         queryExpressions = Objects.requireNonNull(builder.queryExpressions);
         orderByModel = builder.orderByModel;
+        limit = builder.limit;
+        offset = builder.offset;
     }
 
     public <R> Stream<R> mapQueryExpressions(Function<QueryExpressionModel, R> mapper) {
@@ -43,6 +47,14 @@ public Optional<OrderByModel> orderByModel() {
         return Optional.ofNullable(orderByModel);
     }
 
+    public Optional<Long> limit() {
+        return Optional.ofNullable(limit);
+    }
+    
+    public Optional<Long> offset() {
+        return Optional.ofNullable(offset);
+    }
+    
     public SelectStatementProvider render(RenderingStrategy renderingStrategy) {
         return SelectRenderer.withSelectModel(this)
                 .withRenderingStrategy(renderingStrategy)
@@ -57,6 +69,8 @@ public static Builder withQueryExpressions(List<QueryExpressionModel> queryExpre
     public static class Builder {
         private List<QueryExpressionModel> queryExpressions = new ArrayList<>();
         private OrderByModel orderByModel;
+        private Long limit;
+        private Long offset;
 
         public Builder withQueryExpressions(List<QueryExpressionModel> queryExpressions) {
             this.queryExpressions.addAll(queryExpressions);
@@ -68,6 +82,16 @@ public Builder withOrderByModel(OrderByModel orderByModel) {
             return this;
         }
 
+        public Builder withLimit(Long limit) {
+            this.limit = limit;
+            return this;
+        }
+        
+        public Builder withOffset(Long offset) {
+            this.offset = offset;
+            return this;
+        }
+        
         public SelectModel build() {
             return new SelectModel(this);
         }