#64 - Add Criteria API.

We now support Criteria creation and mapping to express where conditions with a fluent API.

databaseClient.select().from("legoset")
  .where(Criteria.of("name").like("John%").and("id").lessThanOrEquals(42055));

databaseClient.delete()
  .from(LegoSet.class)
  .where(Criteria.of("id").is(42055))
  .then()

databaseClient.delete()
  .from(LegoSet.class)
  .where(Criteria.of("id").is(42055))
  .fetch()
  .rowsUpdated()

Original pull request: #106.

Author: mp911de

src/main/java/org/springframework/data/r2dbc/function/BindableOperation.java renamed to src/main/java/org/springframework/data/r2dbc/domain/BindableOperation.java

@@ -1,4 +1,19 @@
-package org.springframework.data.r2dbc.function;
+/*
+ * Copyright 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
+ *
+ *      https://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.springframework.data.r2dbc.domain;
 
 import io.r2dbc.spi.Statement;
 

src/main/java/org/springframework/data/r2dbc/domain/Bindings.java

@@ -0,0 +1,264 @@
+/*
+ * Copyright 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
+ *
+ *      https://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.springframework.data.r2dbc.domain;
+
+import io.r2dbc.spi.Statement;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Spliterator;
+import java.util.function.Consumer;
+
+import org.springframework.data.r2dbc.dialect.BindMarker;
+import org.springframework.data.r2dbc.dialect.BindMarkers;
+import org.springframework.data.util.Streamable;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+
+/**
+ * Value object representing value and {@code NULL} bindings for a {@link Statement} using {@link BindMarkers}.
+ *
+ * @author Mark Paluch
+ */
+public class Bindings implements Streamable<Bindings.Binding> {
+
+	private final Map<BindMarker, Binding> bindings;
+
+	/**
+	 * Create empty {@link Bindings}.
+	 */
+	public Bindings() {
+		this.bindings = Collections.emptyMap();
+	}
+
+	/**
+	 * Create {@link Bindings} from a {@link Map}.
+	 *
+	 * @param bindings must not be {@literal null}.
+	 */
+	public Bindings(Collection<Binding> bindings) {
+
+		Assert.notNull(bindings, "Bindings must not be null");
+
+		Map<BindMarker, Binding> mapping = new LinkedHashMap<>(bindings.size());
+		bindings.forEach(it -> mapping.put(it.getBindMarker(), it));
+		this.bindings = mapping;
+	}
+
+	Bindings(Map<BindMarker, Binding> bindings) {
+		this.bindings = bindings;
+	}
+
+	protected Map<BindMarker, Binding> getBindings() {
+		return bindings;
+	}
+
+	/**
+	 * Merge this bindings with an other {@link Bindings} object and create a new merged {@link Bindings} object.
+	 *
+	 * @param left the left object to merge with.
+	 * @param right the right object to merge with.
+	 * @return a new, merged {@link Bindings} object.
+	 */
+	public static Bindings merge(Bindings left, Bindings right) {
+
+		Assert.notNull(left, "Left side Bindings must not be null");
+		Assert.notNull(right, "Right side Bindings must not be null");
+
+		List<Binding> result = new ArrayList<>(left.getBindings().size() + right.getBindings().size());
+
+		result.addAll(left.getBindings().values());
+		result.addAll(right.getBindings().values());
+
+		return new Bindings(result);
+	}
+
+	/**
+	 * Apply the bindings to a {@link Statement}.
+	 *
+	 * @param statement the statement to apply to.
+	 */
+	public void apply(Statement statement) {
+
+		Assert.notNull(statement, "Statement must not be null");
+		this.bindings.forEach((marker, binding) -> binding.apply(statement));
+	}
+
+	/**
+	 * Performs the given action for each binding of this {@link Bindings} until all bindings have been processed or the
+	 * action throws an exception. Actions are performed in the order of iteration (if an iteration order is specified).
+	 * Exceptions thrown by the action are relayed to the
+	 *
+	 * @param action The action to be performed for each {@link Binding}.
+	 */
+	public void forEach(Consumer<? super Binding> action) {
+		this.bindings.forEach((marker, binding) -> action.accept(binding));
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see java.lang.Iterable#iterator()
+	 */
+	@Override
+	public Iterator<Binding> iterator() {
+		return this.bindings.values().iterator();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see java.lang.Iterable#spliterator()
+	 */
+	@Override
+	public Spliterator<Binding> spliterator() {
+		return this.bindings.values().spliterator();
+	}
+
+	/**
+	 * Base class for value objects representing a value or a {@code NULL} binding.
+	 */
+	public abstract static class Binding {
+
+		private final BindMarker marker;
+
+		protected Binding(BindMarker marker) {
+			this.marker = marker;
+		}
+
+		/**
+		 * @return the associated {@link BindMarker}.
+		 */
+		public BindMarker getBindMarker() {
+			return marker;
+		}
+
+		/**
+		 * Return {@literal true} if there is a value present, otherwise {@literal false} for a {@code NULL} binding.
+		 *
+		 * @return {@literal true} if there is a value present, otherwise {@literal false} for a {@code NULL} binding.
+		 */
+		public abstract boolean hasValue();
+
+		/**
+		 * Return {@literal true} if this is is a {@code NULL} binding.
+		 *
+		 * @return {@literal true} if this is is a {@code NULL} binding.
+		 */
+		public boolean isNull() {
+			return !hasValue();
+		}
+
+		/**
+		 * Returns the value of this binding. Can be {@literal null} if this is a {@code NULL} binding.
+		 *
+		 * @return value of this binding. Can be {@literal null} if this is a {@code NULL} binding.
+		 */
+		@Nullable
+		public abstract Object getValue();
+
+		/**
+		 * Applies the binding to a {@link Statement}.
+		 *
+		 * @param statement the statement to apply to.
+		 */
+		public abstract void apply(Statement statement);
+	}
+
+	/**
+	 * Value binding.
+	 */
+	public static class ValueBinding extends Binding {
+
+		private final Object value;
+
+		public ValueBinding(BindMarker marker, Object value) {
+			super(marker);
+			this.value = value;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.query.Bindings.Binding#hasValue()
+		 */
+		public boolean hasValue() {
+			return true;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.query.Bindings.Binding#getValue()
+		 */
+		public Object getValue() {
+			return value;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.query.Bindings.Binding#apply(io.r2dbc.spi.Statement)
+		 */
+		@Override
+		public void apply(Statement statement) {
+			getBindMarker().bind(statement, getValue());
+		}
+	}
+
+	/**
+	 * {@code NULL} binding.
+	 */
+	public static class NullBinding extends Binding {
+
+		private final Class<?> valueType;
+
+		public NullBinding(BindMarker marker, Class<?> valueType) {
+			super(marker);
+			this.valueType = valueType;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.query.Bindings.Binding#hasValue()
+		 */
+		public boolean hasValue() {
+			return false;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.query.Bindings.Binding#getValue()
+		 */
+		@Nullable
+		public Object getValue() {
+			return null;
+		}
+
+		public Class<?> getValueType() {
+			return valueType;
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.r2dbc.function.query.Bindings.Binding#apply(io.r2dbc.spi.Statement)
+		 */
+		@Override
+		public void apply(Statement statement) {
+			getBindMarker().bindNull(statement, getValueType());
+		}
+	}
+}