Add Support for Various Locking Functions in Select Statements

CHANGELOG.md

@@ -96,6 +96,10 @@ Runtime behavior changes:
   rendering if a null value is passed in
 - The JOIN syntax is updated and now allows full boolean expressions like a WHERE clause. The prior JOIN syntax
   is deprecated and will be removed in a future release.
+- Add support for locking options in select statements (for update, for share, etc.) This is not an abstraction of
+  these concepts for different databases it simply adds known clauses to a generated SQL statement. You should always
+  test to make sure these functions work in your target database. Currently, we support, and test, the options
+  supported by PostgreSQL.
 
 ## Release 1.5.2 - June 3, 2024
 

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

@@ -25,14 +25,14 @@
 import org.mybatis.dynamic.sql.SqlCriterion;
 import org.mybatis.dynamic.sql.VisitableCondition;
 
-public abstract class AbstractHavingStarter<F extends AbstractHavingFinisher<?>> {
+public interface AbstractHavingStarter<F extends AbstractHavingFinisher<?>> {
 
-    public <T> F having(BindableColumn<T> column, VisitableCondition<T> condition,
+    default <T> F having(BindableColumn<T> column, VisitableCondition<T> condition,
                         AndOrCriteriaGroup... subCriteria) {
         return having(column, condition, Arrays.asList(subCriteria));
     }
 
-    public <T> F having(BindableColumn<T> column, VisitableCondition<T> condition,
+    default <T> F having(BindableColumn<T> column, VisitableCondition<T> condition,
                         List<AndOrCriteriaGroup> subCriteria) {
         SqlCriterion sqlCriterion = ColumnAndConditionCriterion.withColumn(column)
                 .withCondition(condition)
@@ -42,11 +42,11 @@ public <T> F having(BindableColumn<T> column, VisitableCondition<T> condition,
         return initialize(sqlCriterion);
     }
 
-    public F having(SqlCriterion initialCriterion, AndOrCriteriaGroup... subCriteria) {
+    default F having(SqlCriterion initialCriterion, AndOrCriteriaGroup... subCriteria) {
         return having(initialCriterion, Arrays.asList(subCriteria));
     }
 
-    public F having(SqlCriterion initialCriterion, List<AndOrCriteriaGroup> subCriteria) {
+    default F having(SqlCriterion initialCriterion, List<AndOrCriteriaGroup> subCriteria) {
         SqlCriterion sqlCriterion = new CriteriaGroup.Builder()
                 .withInitialCriterion(initialCriterion)
                 .withSubCriteria(subCriteria)
@@ -55,9 +55,9 @@ public F having(SqlCriterion initialCriterion, List<AndOrCriteriaGroup> subCrite
         return initialize(sqlCriterion);
     }
 
-    protected abstract F having();
+    F having();
 
-    public F applyHaving(HavingApplier havingApplier) {
+    default F applyHaving(HavingApplier havingApplier) {
         F finisher = having();
         havingApplier.accept(finisher);
         return finisher;

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

@@ -17,11 +17,11 @@
 
 import org.mybatis.dynamic.sql.util.Buildable;
 
-public class HavingDSL extends AbstractHavingStarter<HavingDSL.StandaloneHavingFinisher> {
+public class HavingDSL implements AbstractHavingStarter<HavingDSL.StandaloneHavingFinisher> {
     private final StandaloneHavingFinisher havingFinisher = new StandaloneHavingFinisher();
 
     @Override
-    protected StandaloneHavingFinisher having() {
+    public StandaloneHavingFinisher having() {
         return havingFinisher;
     }
 

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

@@ -29,8 +29,7 @@
 import org.mybatis.dynamic.sql.util.Buildable;
 import org.mybatis.dynamic.sql.util.ConfigurableStatement;
 
-public class MultiSelectDSL implements Buildable<MultiSelectModel>, ConfigurableStatement<MultiSelectDSL>,
-        PagingDSL<MultiSelectModel> {
+public class MultiSelectDSL implements Buildable<MultiSelectModel>, ConfigurableStatement<MultiSelectDSL> {
     private final List<UnionQuery> unionQueries = new ArrayList<>();
     private final SelectModel initialSelect;
     private @Nullable OrderByModel orderByModel;
@@ -62,22 +61,31 @@ public MultiSelectDSL orderBy(Collection<? extends SortSpecification> columns) {
         return this;
     }
 
-    @Override
-    public LimitFinisher<MultiSelectModel> limitWhenPresent(@Nullable Long limit) {
+    public LimitFinisher limit(long limit) {
+        return limitWhenPresent(limit);
+    }
+
+    public LimitFinisher limitWhenPresent(@Nullable Long limit) {
         this.limit = limit;
-        return new LocalLimitFinisher();
+        return new LimitFinisher();
     }
 
-    @Override
-    public OffsetFirstFinisher<MultiSelectModel> offsetWhenPresent(@Nullable Long offset) {
+    public OffsetFirstFinisher offset(long offset) {
+        return offsetWhenPresent(offset);
+    }
+
+    public OffsetFirstFinisher offsetWhenPresent(@Nullable Long offset) {
         this.offset = offset;
-        return new LocalOffsetFirstFinisher();
+        return new OffsetFirstFinisher();
     }
 
-    @Override
-    public FetchFirstFinisher<MultiSelectModel> fetchFirstWhenPresent(@Nullable Long fetchFirstRows) {
+    public FetchFirstFinisher fetchFirst(long fetchFirstRows) {
+        return fetchFirstWhenPresent(fetchFirstRows);
+    }
+
+    public FetchFirstFinisher fetchFirstWhenPresent(@Nullable Long fetchFirstRows) {
         this.fetchFirstRows = fetchFirstRows;
-        return () -> this;
+        return new FetchFirstFinisher();
     }
 
     @Override
@@ -105,25 +113,40 @@ public MultiSelectDSL configureStatement(Consumer<StatementConfiguration> consum
         return this;
     }
 
-    abstract class BaseBuildable implements Buildable<MultiSelectModel> {
+    public class OffsetFirstFinisher implements Buildable<MultiSelectModel> {
+        public FetchFirstFinisher fetchFirst(long fetchFirstRows) {
+            return fetchFirstWhenPresent(fetchFirstRows);
+        }
+
+        public FetchFirstFinisher fetchFirstWhenPresent(@Nullable Long fetchFirstRows) {
+            MultiSelectDSL.this.fetchFirstRows = fetchFirstRows;
+            return new FetchFirstFinisher();
+        }
+
         @Override
         public MultiSelectModel build() {
             return MultiSelectDSL.this.build();
         }
     }
 
-    class LocalOffsetFirstFinisher extends BaseBuildable implements OffsetFirstFinisher<MultiSelectModel> {
+    public class LimitFinisher implements Buildable<MultiSelectModel> {
+        public MultiSelectDSL offset(long offset) {
+            return offsetWhenPresent(offset);
+        }
+
+        public MultiSelectDSL offsetWhenPresent(@Nullable Long offset) {
+            MultiSelectDSL.this.offset = offset;
+            return MultiSelectDSL.this;
+        }
+
         @Override
-        public FetchFirstFinisher<MultiSelectModel> fetchFirstWhenPresent(Long fetchFirstRows) {
-            MultiSelectDSL.this.fetchFirstRows = fetchFirstRows;
-            return () -> MultiSelectDSL.this;
+        public MultiSelectModel build() {
+            return MultiSelectDSL.this.build();
         }
     }
 
-    class LocalLimitFinisher extends BaseBuildable implements LimitFinisher<MultiSelectModel> {
-        @Override
-        public Buildable<MultiSelectModel> offsetWhenPresent(Long offset) {
-            MultiSelectDSL.this.offset = offset;
+    public class FetchFirstFinisher {
+        public MultiSelectDSL rowsOnly() {
             return MultiSelectDSL.this;
         }
     }