#282 - Add support for query derivation.

We now support query derivation for R2DBC repositories:

interface ReactivePersonRepository extends ReactiveSortingRepository<Person, String> {

  Flux<Person> findByFirstname(String firstname);

  Flux<Person> findByFirstname(Publisher<String> firstname);

  Mono<Person> findByFirstnameAndLastname(String firstname, String lastname);

  Flux<Person> findFirstByLastnameLike(String pattern);
}

Original pull request: #295.

Author: rchigvintsev

src/main/java/org/springframework/data/r2dbc/core/DefaultStatementMapper.java

@@ -226,6 +226,15 @@ public PreparedOperation<Delete> getMappedObject(DeleteSpec deleteSpec) {
 		return getMappedObject(deleteSpec, null);
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.r2dbc.function.StatementMapper#getRenderContext()
+	 */
+	@Override
+	public RenderContext getRenderContext() {
+		return renderContext;
+	}
+
 	private PreparedOperation<Delete> getMappedObject(DeleteSpec deleteSpec,
 			@Nullable RelationalPersistentEntity<?> entity) {
 
@@ -375,5 +384,14 @@ public PreparedOperation<?> getMappedObject(UpdateSpec updateSpec) {
 		public PreparedOperation<?> getMappedObject(DeleteSpec deleteSpec) {
 			return DefaultStatementMapper.this.getMappedObject(deleteSpec, this.entity);
 		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.StatementMapper#getRenderContext()
+		 */
+		@Override
+		public RenderContext getRenderContext() {
+			return DefaultStatementMapper.this.getRenderContext();
+		}
 	}
 }

src/main/java/org/springframework/data/r2dbc/core/StatementMapper.java

@@ -34,6 +34,7 @@
 import org.springframework.data.relational.core.sql.Expression;
 import org.springframework.data.relational.core.sql.SqlIdentifier;
 import org.springframework.data.relational.core.sql.Table;
+import org.springframework.data.relational.core.sql.render.RenderContext;
 import org.springframework.lang.Nullable;
 
 /**
@@ -177,6 +178,16 @@ default DeleteSpec createDelete(SqlIdentifier table) {
 		return DeleteSpec.create(table);
 	}
 
+	/**
+	 * Returns {@link RenderContext}.
+	 *
+	 * @return {@link RenderContext} instance or {@literal null} if {@link RenderContext} is not available
+	 */
+	@Nullable
+	default RenderContext getRenderContext() {
+		return null;
+	}
+
 	/**
 	 * {@code SELECT} specification.
 	 */

src/main/java/org/springframework/data/r2dbc/query/Criteria.java

@@ -57,20 +57,28 @@ public class Criteria {
 	private final @Nullable SqlIdentifier column;
 	private final @Nullable Comparator comparator;
 	private final @Nullable Object value;
+	private final boolean ignoreCase;
 
 	private Criteria(SqlIdentifier column, Comparator comparator, @Nullable Object value) {
-		this(null, Combinator.INITIAL, Collections.emptyList(), column, comparator, value);
+		this(null, Combinator.INITIAL, Collections.emptyList(), column, comparator, value, false);
 	}
 
 	private Criteria(@Nullable Criteria previous, Combinator combinator, List<Criteria> group,
 			@Nullable SqlIdentifier column, @Nullable Comparator comparator, @Nullable Object value) {
+		this(previous, combinator, group, column, comparator, value, false);
+	}
+
+	private Criteria(@Nullable Criteria previous, Combinator combinator, List<Criteria> group,
+			@Nullable SqlIdentifier column, @Nullable Comparator comparator, @Nullable Object value,
+			boolean ignoreCase) {
 
 		this.previous = previous;
 		this.combinator = previous != null && previous.isEmpty() ? Combinator.INITIAL : combinator;
 		this.group = group;
 		this.column = column;
 		this.comparator = comparator;
 		this.value = value;
+		this.ignoreCase = ignoreCase;
 	}
 
 	private Criteria(@Nullable Criteria previous, Combinator combinator, List<Criteria> group) {
@@ -81,6 +89,7 @@ private Criteria(@Nullable Criteria previous, Combinator combinator, List<Criter
 		this.column = null;
 		this.comparator = null;
 		this.value = null;
+		this.ignoreCase = false;
 	}
 
 	/**
@@ -236,6 +245,19 @@ public Criteria or(List<Criteria> criteria) {
 		return new Criteria(Criteria.this, Combinator.OR, criteria);
 	}
 
+	/**
+	 * Creates a new {@link Criteria} with the given "ignore case" flag.
+	 *
+	 * @param ignoreCase {@literal true} if comparison should be done in case-insensitive way
+	 * @return a new {@link Criteria} object
+	 */
+	public Criteria ignoreCase(boolean ignoreCase) {
+		if (this.ignoreCase != ignoreCase) {
+			return new Criteria(previous, combinator, group, column, comparator, value, ignoreCase);
+		}
+		return this;
+	}
+
 	/**
 	 * @return the previous {@link Criteria} object. Can be {@literal null} if there is no previous {@link Criteria}.
 	 * @see #hasPrevious()
@@ -338,8 +360,17 @@ Object getValue() {
 		return value;
 	}
 
+	/**
+	 * Checks whether comparison should be done in case-insensitive way.
+	 *
+	 * @return {@literal true} if comparison should be done in case-insensitive way
+	 */
+	boolean isIgnoreCase() {
+		return ignoreCase;
+	}
+
 	enum Comparator {
-		INITIAL, EQ, NEQ, LT, LTE, GT, GTE, IS_NULL, IS_NOT_NULL, LIKE, NOT_IN, IN,
+		INITIAL, EQ, NEQ, LT, LTE, GT, GTE, IS_NULL, IS_NOT_NULL, LIKE, NOT_LIKE, NOT_IN, IN, IS_TRUE, IS_FALSE
 	}
 
 	enum Combinator {
@@ -428,6 +459,14 @@ public interface CriteriaStep {
 		 */
 		Criteria like(Object value);
 
+		/**
+		 * Creates a {@link Criteria} using {@code NOT LIKE}.
+		 *
+		 * @param value must not be {@literal null}
+		 * @return a new {@link Criteria} object
+		 */
+		Criteria notLike(Object value);
+
 		/**
 		 * Creates a {@link Criteria} using {@code IS NULL}.
 		 */
@@ -437,6 +476,20 @@ public interface CriteriaStep {
 		 * Creates a {@link Criteria} using {@code IS NOT NULL}.
 		 */
 		Criteria isNotNull();
+
+		/**
+		 * Creates a {@link Criteria} using {@code IS TRUE}.
+		 *
+		 * @return a new {@link Criteria} object
+		 */
+		Criteria isTrue();
+
+		/**
+		 * Creates a {@link Criteria} using {@code IS FALSE}.
+		 *
+		 * @return a new {@link Criteria} object
+		 */
+		Criteria isFalse();
 	}
 
 	/**
@@ -596,6 +649,16 @@ public Criteria like(Object value) {
 			return createCriteria(Comparator.LIKE, value);
 		}
 
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.query.Criteria.CriteriaStep#notLike(java.lang.Object)
+		 */
+		@Override
+		public Criteria notLike(Object value) {
+			Assert.notNull(value, "Value must not be null!");
+			return createCriteria(Comparator.NOT_LIKE, value);
+		}
+
 		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.data.r2dbc.function.query.Criteria.CriteriaStep#isNull()
@@ -614,6 +677,24 @@ public Criteria isNotNull() {
 			return createCriteria(Comparator.IS_NOT_NULL, null);
 		}
 
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.query.Criteria.CriteriaStep#isTrue()
+		 */
+		@Override
+		public Criteria isTrue() {
+			return createCriteria(Comparator.IS_TRUE, null);
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.query.Criteria.CriteriaStep#isFalse()
+		 */
+		@Override
+		public Criteria isFalse() {
+			return createCriteria(Comparator.IS_FALSE, null);
+		}
+
 		protected Criteria createCriteria(Comparator comparator, Object value) {
 			return new Criteria(this.property, comparator, value);
 		}