Add Support for Fetch First Based Paging

pom.xml

@@ -138,13 +138,13 @@
     <dependency>
       <groupId>org.hsqldb</groupId>
       <artifactId>hsqldb</artifactId>
-      <version>2.4.1</version>
+      <version>2.5.0</version>
       <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-jdbc</artifactId>
-      <version>5.1.7.RELEASE</version>
+      <version>5.1.8.RELEASE</version>
       <scope>test</scope>
     </dependency>
     <dependency>

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

@@ -40,15 +40,17 @@ protected SqlTable(Supplier<Optional<String>> schemaSupplier, String tableName)
         this(Optional::empty, schemaSupplier, tableName);
     }
 
-    protected SqlTable(Supplier<Optional<String>> catalogSupplier, Supplier<Optional<String>> schemaSupplier, String tableName) {
+    protected SqlTable(Supplier<Optional<String>> catalogSupplier, Supplier<Optional<String>> schemaSupplier,
+            String tableName) {
         Objects.requireNonNull(catalogSupplier);
         Objects.requireNonNull(schemaSupplier);
         Objects.requireNonNull(tableName);
 
         this.nameSupplier = () -> compose(catalogSupplier, schemaSupplier, tableName);
     }
 
-    private String compose(Supplier<Optional<String>> catalogSupplier, Supplier<Optional<String>> schemaSupplier, String tableName) {
+    private String compose(Supplier<Optional<String>> catalogSupplier, Supplier<Optional<String>> schemaSupplier,
+            String tableName) {
         return catalogSupplier.get().map(c -> compose(c, schemaSupplier, tableName))
                 .orElse(compose(schemaSupplier, tableName));
     }

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

@@ -0,0 +1,61 @@
+/**
+ *    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.
+ *    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.
+ */
+package org.mybatis.dynamic.sql.select;
+
+import java.util.Optional;
+
+public class FetchFirstPagingModel implements PagingModel {
+
+    private Long fetchFirstRows;
+    private Long offset;
+
+    private FetchFirstPagingModel(Builder builder) {
+        this.fetchFirstRows = builder.fetchFirstRows;
+        this.offset = builder.offset;
+    }
+
+    public Optional<Long> fetchFirstRows() {
+        return Optional.ofNullable(fetchFirstRows);
+    }
+
+    public Optional<Long> offset() {
+        return Optional.ofNullable(offset);
+    }
+
+    @Override
+    public <R> R accept(PagingModelVisitor<R> visitor) {
+        return visitor.visit(this);
+    }
+
+    public static class Builder {
+        private Long fetchFirstRows;
+        private Long offset;
+
+        public Builder withFetchFirstRows(Long fetchFirstRows) {
+            this.fetchFirstRows = fetchFirstRows;
+            return this;
+        }
+
+        public Builder withOffset(Long offset) {
+            this.offset = offset;
+            return this;
+        }
+
+        public FetchFirstPagingModel build() {
+            return new FetchFirstPagingModel(this);
+        }
+    }
+}

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

@@ -0,0 +1,61 @@
+/**
+ *    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.
+ *    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.
+ */
+package org.mybatis.dynamic.sql.select;
+
+import java.util.Optional;
+
+public class LimitAndOffsetPagingModel implements PagingModel {
+
+    private Long limit;
+    private Long offset;
+
+    private LimitAndOffsetPagingModel(Builder builder) {
+        this.limit = builder.limit;
+        this.offset = builder.offset;
+    }
+
+    public Optional<Long> limit() {
+        return Optional.ofNullable(limit);
+    }
+
+    public Optional<Long> offset() {
+        return Optional.ofNullable(offset);
+    }
+
+    @Override
+    public <R> R accept(PagingModelVisitor<R> visitor) {
+        return visitor.visit(this);
+    }
+
+    public static class Builder {
+        private Long limit;
+        private Long offset;
+
+        public Builder withLimit(Long limit) {
+            this.limit = limit;
+            return this;
+        }
+
+        public Builder withOffset(Long offset) {
+            this.offset = offset;
+            return this;
+        }
+
+        public LimitAndOffsetPagingModel build() {
+            return new LimitAndOffsetPagingModel(this);
+        }
+    }
+}

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

@@ -0,0 +1,20 @@
+/**
+ *    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.
+ *    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.
+ */
+package org.mybatis.dynamic.sql.select;
+
+public interface PagingModel {
+    <R> R accept(PagingModelVisitor<R> visitor);
+}

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

@@ -0,0 +1,22 @@
+/**
+ *    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.
+ *    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.
+ */
+package org.mybatis.dynamic.sql.select;
+
+public interface PagingModelVisitor<R> {
+    R visit(LimitAndOffsetPagingModel pagingModel);
+
+    R visit(FetchFirstPagingModel pagingModel);
+}

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

@@ -149,11 +149,16 @@ public SelectDSL<R>.LimitFinisher limit(long limit) {
         return selectDSL.limit(limit);
     }
 
-    public SelectDSL<R>.OffsetFinisher offset(long offset) {
+    public SelectDSL<R>.OffsetFirstFinisher offset(long offset) {
         selectDSL.addQueryExpression(buildModel());
         return selectDSL.offset(offset);
     }
 
+    public SelectDSL<R>.FetchFirstFinisher fetchFirst(long fetchFirstRows) {
+        selectDSL.addQueryExpression(buildModel());
+        return selectDSL.fetchFirst(fetchFirstRows);
+    }
+
     public static class FromGatherer<R> {
         private FromGathererBuilder<R> builder;
         private Map<SqlTable, String> tableAliasMap = new HashMap<>();
@@ -250,12 +255,18 @@ public SelectDSL<R>.LimitFinisher limit(long limit) {
             return selectDSL.limit(limit);
         }
 
-        public SelectDSL<R>.OffsetFinisher offset(long offset) {
+        public SelectDSL<R>.OffsetFirstFinisher offset(long offset) {
             whereModel = buildWhereModel();
             selectDSL.addQueryExpression(buildModel());
             return selectDSL.offset(offset);
         }
 
+        public SelectDSL<R>.FetchFirstFinisher fetchFirst(long fetchFirstRows) {
+            whereModel = buildWhereModel();
+            selectDSL.addQueryExpression(buildModel());
+            return selectDSL.fetchFirst(fetchFirstRows);
+        }
+
         @Override
         public R build() {
             whereModel = buildWhereModel();
@@ -413,7 +424,7 @@ public SelectDSL<R>.LimitFinisher limit(long limit) {
             return selectDSL.limit(limit);
         }
 
-        public SelectDSL<R>.OffsetFinisher offset(long offset) {
+        public SelectDSL<R>.OffsetFirstFinisher offset(long offset) {
             joinModel = buildJoinModel();
             selectDSL.addQueryExpression(buildModel());
             return selectDSL.offset(offset);
@@ -435,7 +446,7 @@ public SelectDSL<R>.LimitFinisher limit(long limit) {
             return selectDSL.limit(limit);
         }
 
-        public SelectDSL<R>.OffsetFinisher offset(long offset) {
+        public SelectDSL<R>.OffsetFirstFinisher offset(long offset) {
             return selectDSL.offset(offset);
         }
     }

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

@@ -38,8 +38,7 @@ 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 PagingModel pagingModel;
 
     private SelectDSL(Function<SelectModel, R> adapterFunction) {
         this.adapterFunction = Objects.requireNonNull(adapterFunction);
@@ -100,39 +99,116 @@ void setOrderByModel(OrderByModel orderByModel) {
     }
 
     public LimitFinisher limit(long limit) {
-        this.limit = limit;
-        return new LimitFinisher();
+        return new LimitFinisher(limit);
     }
 
-    public OffsetFinisher offset(long offset) {
-        this.offset = offset;
-        return new OffsetFinisher();
+    public OffsetFirstFinisher offset(long offset) {
+        return new OffsetFirstFinisher(offset);
+    }
+
+    public FetchFirstFinisher fetchFirst(long fetchFirstRows) {
+        return new FetchFirstFinisher(fetchFirstRows);
     }
 
     @Override
     public R build() {
         SelectModel selectModel = SelectModel.withQueryExpressions(queryExpressions)
                 .withOrderByModel(orderByModel)
-                .withLimit(limit)
-                .withOffset(offset)
+                .withPagingModel(pagingModel)
                 .build();
         return adapterFunction.apply(selectModel);
     }
 
     public class LimitFinisher implements Buildable<R> {
-        public OffsetFinisher offset(int offset) {
-            return SelectDSL.this.offset(offset);
+        private long limit;
+
+        public LimitFinisher(long limit) {
+            this.limit = limit;
+        }
+
+        public OffsetFinisher offset(long offset) {
+            return new OffsetFinisher(limit, offset);
         }
 
         @Override
         public R build() {
+            SelectDSL.this.pagingModel = new LimitAndOffsetPagingModel.Builder()
+                    .withLimit(limit)
+                    .build();
             return SelectDSL.this.build();
         }
     }
 
     public class OffsetFinisher implements Buildable<R> {
+        private LimitAndOffsetPagingModel pagingModel;
+
+        public OffsetFinisher(long limit, long offset) {
+            pagingModel = new LimitAndOffsetPagingModel.Builder()
+                    .withLimit(limit)
+                    .withOffset(offset)
+                    .build();
+        }
+
+        @Override
+        public R build() {
+            SelectDSL.this.pagingModel = pagingModel;
+            return SelectDSL.this.build();
+        }
+    }
+
+    public class OffsetFirstFinisher implements Buildable<R> {
+        private long offset;
+
+        public OffsetFirstFinisher(long offset) {
+            this.offset = offset;
+        }
+
+        public FetchFirstFinisher fetchFirst(long fetchFirstRows) {
+            return new FetchFirstFinisher(offset, fetchFirstRows);
+        }
+
+        @Override
+        public R build() {
+            SelectDSL.this.pagingModel = new LimitAndOffsetPagingModel.Builder()
+                    .withOffset(offset)
+                    .build();
+            return SelectDSL.this.build();
+        }
+    }
+
+    public class FetchFirstFinisher {
+        private Long offset;
+        private Long fetchFirstRows;
+
+        public FetchFirstFinisher(long fetchFirstRows) {
+            this.fetchFirstRows = fetchFirstRows;
+        }
+
+        public FetchFirstFinisher(long offset, long fetchFirstRows) {
+            this.offset = offset;
+            this.fetchFirstRows = fetchFirstRows;
+        }
+
+        public RowsOnlyFinisher rowsOnly() {
+            return new RowsOnlyFinisher(offset, fetchFirstRows);
+        }
+    }
+
+    public class RowsOnlyFinisher implements Buildable<R> {
+        private Long offset;
+        private Long fetchFirstRows;
+
+        public RowsOnlyFinisher(Long offset, Long fetchFirstRows) {
+            this.offset = offset;
+            this.fetchFirstRows = fetchFirstRows;
+        }
+
         @Override
         public R build() {
+            SelectDSL.this.pagingModel = new FetchFirstPagingModel.Builder()
+                    .withOffset(offset)
+                    .withFetchFirstRows(fetchFirstRows)
+                    .build();
             return SelectDSL.this.build();
         }
     }