Fix derived queries with boolean literals.

`IsTrue` and `IsFalse` queries no longer use a literal in the query, but a bind parameter.
This allows Spring Data JDBC or the JDBC driver to convert the passed boolean value to whatever is required in the database.

For Oracle converter where added to support storing and loading booleans as NUMBER(1,0) where 0 is false and everything else is true.

Closes #908
Original pull request #983

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/config/AbstractJdbcConfiguration.java

@@ -133,7 +133,7 @@ public class AbstractJdbcConfiguration implements ApplicationContextAware {
 		}
 	}
 
-	private List<?> userConverters() {
+	protected List<?> userConverters() {
 		return Collections.emptyList();
 	}
 

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/query/QueryMapper.java

@@ -402,11 +402,15 @@ class QueryMapper {
 		}
 
 		if (comparator == Comparator.IS_TRUE) {
-			return column.isEqualTo(SQL.literalOf(true));
+
+			Expression bind = bindBoolean(column, parameterSource, true);
+			return column.isEqualTo(bind);
 		}
 
 		if (comparator == Comparator.IS_FALSE) {
-			return column.isEqualTo(SQL.literalOf(false));
+
+			Expression bind = bindBoolean(column, parameterSource, false);
+			return column.isEqualTo(bind);
 		}
 
 		Expression columnExpression = column;
@@ -495,6 +499,12 @@ class QueryMapper {
 		}
 	}
 
+	private Expression bindBoolean(Column column, MapSqlParameterSource parameterSource, boolean value) {
+
+		Object converted = converter.writeValue(value, ClassTypeInformation.OBJECT);
+		return bind(converted, Types.BIT, parameterSource, column.getName().getReference());
+	}
+
 	Field createPropertyField(@Nullable RelationalPersistentEntity<?> entity, SqlIdentifier key) {
 		return entity == null ? new Field(key) : new MetadataBackedField(key, entity, mappingContext, converter);
 	}

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/repository/JdbcRepositoryIntegrationTests.java

@@ -501,6 +501,19 @@ public class JdbcRepositoryIntegrationTests {
 		repository.updateWithIntervalCalculation(23L, LocalDateTime.now());
 	}
 
+	@Test // #908
+	void derivedQueryWithBooleanLiteralFindsCorrectValues() {
+
+		repository.save(createDummyEntity());
+		DummyEntity entity = createDummyEntity();
+		entity.flag = true;
+		entity = repository.save(entity);
+
+		List<DummyEntity> result = repository.findByFlagTrue();
+
+		assertThat(result).extracting(e -> e.idProp).containsExactly(entity.idProp);
+	}
+
 	private Instant createDummyBeforeAndAfterNow() {
 
 		Instant now = Instant.now();
@@ -570,6 +583,8 @@ public class JdbcRepositoryIntegrationTests {
 		@Modifying
 		@Query("UPDATE dummy_entity SET point_in_time = :start - interval '30 minutes' WHERE id_prop = :id")
 		void updateWithIntervalCalculation(@Param("id") Long id, @Param("start") LocalDateTime start);
+
+		List<DummyEntity> findByFlagTrue();
 	}
 
 	@Configuration
@@ -616,10 +631,12 @@ public class JdbcRepositoryIntegrationTests {
 	@Data
 	@NoArgsConstructor
 	static class DummyEntity {
+
 		String name;
 		Instant pointInTime;
 		OffsetDateTime offsetDateTime;
 		@Id private Long idProp;
+		boolean flag;
 
 		public DummyEntity(String name) {
 			this.name = name;

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/repository/config/AbstractJdbcConfigurationIntegrationTests.java

@@ -15,12 +15,13 @@
  */
 package org.springframework.data.jdbc.repository.config;
 
+import static java.util.Arrays.*;
 import static org.assertj.core.api.Assertions.*;
 import static org.mockito.Mockito.*;
 
-import java.util.Arrays;
+import java.util.Collection;
-import java.util.Collections;
 import java.util.List;
+import java.util.Optional;
 import java.util.function.Consumer;
 
 import org.junit.jupiter.api.Test;
@@ -29,6 +30,7 @@ import org.springframework.context.annotation.AnnotationConfigApplicationContext
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.convert.converter.Converter;
+import org.springframework.data.convert.ReadingConverter;
 import org.springframework.data.convert.WritingConverter;
 import org.springframework.data.jdbc.core.JdbcAggregateTemplate;
 import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
@@ -36,7 +38,9 @@ import org.springframework.data.jdbc.core.convert.JdbcConverter;
 import org.springframework.data.jdbc.core.convert.JdbcCustomConversions;
 import org.springframework.data.jdbc.core.mapping.JdbcMappingContext;
 import org.springframework.data.relational.core.dialect.Dialect;
-import org.springframework.data.relational.core.dialect.HsqlDbDialect;
+import org.springframework.data.relational.core.dialect.LimitClause;
+import org.springframework.data.relational.core.dialect.LockClause;
+import org.springframework.data.relational.core.sql.render.SelectRenderContext;
 import org.springframework.jdbc.core.JdbcOperations;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
@@ -53,7 +57,7 @@ public class AbstractJdbcConfigurationIntegrationTests {
 
 		assertApplicationContext(context -> {
 
-			List<Class<?>> expectedBeanTypes = Arrays.asList(DataAccessStrategy.class, //
+			List<Class<?>> expectedBeanTypes = asList(DataAccessStrategy.class, //
 					JdbcMappingContext.class, //
 					JdbcConverter.class, //
 					JdbcCustomConversions.class, //
@@ -70,11 +74,26 @@ public class AbstractJdbcConfigurationIntegrationTests {
 	void registersSimpleTypesFromCustomConversions() {
 
 		assertApplicationContext(context -> {
+
 			JdbcMappingContext mappingContext = context.getBean(JdbcMappingContext.class);
 			assertThat( //
 					mappingContext.getPersistentEntity(AbstractJdbcConfigurationUnderTest.Blah.class) //
 			).describedAs("Blah should not be an entity, since there is a WritingConversion configured for it") //
 					.isNull();
+
+		}, AbstractJdbcConfigurationUnderTest.class, Infrastructure.class);
+	}
+
+	@Test // #908
+	void userProvidedConversionsOverwriteDialectSpecificConversions() {
+
+		assertApplicationContext(applicationContext -> {
+
+			Optional<Class<?>> customWriteTarget = applicationContext.getBean(JdbcCustomConversions.class)
+					.getCustomWriteTarget(Boolean.class);
+
+			assertThat(customWriteTarget).contains(String.class);
+
 		}, AbstractJdbcConfigurationUnderTest.class, Infrastructure.class);
 	}
 
@@ -106,12 +125,12 @@ public class AbstractJdbcConfigurationIntegrationTests {
 		@Override
 		@Bean
 		public Dialect jdbcDialect(NamedParameterJdbcOperations operations) {
-			return HsqlDbDialect.INSTANCE;
+			return new DummyDialect();
 		}
 
 		@Override
-		public JdbcCustomConversions jdbcCustomConversions() {
+		protected List<?> userConverters() {
-			return new JdbcCustomConversions(Collections.singletonList(Blah2BlubbConverter.INSTANCE));
+			return asList(Blah2BlubbConverter.INSTANCE, BooleanToYnConverter.INSTANCE);
 		}
 
 		@WritingConverter
@@ -127,6 +146,59 @@ public class AbstractJdbcConfigurationIntegrationTests {
 		private static class Blah {}
 
 		private static class Blubb {}
+
+		private static class DummyDialect implements Dialect {
+			@Override
+			public LimitClause limit() {
+				return null;
+			}
+
+			@Override
+			public LockClause lock() {
+				return null;
+			}
+
+			@Override
+			public SelectRenderContext getSelectContext() {
+				return null;
+			}
+
+			@Override
+			public Collection<Object> getConverters() {
+				return asList(BooleanToNumberConverter.INSTANCE, NumberToBooleanConverter.INSTANCE);
+			}
+		}
+
+		@WritingConverter
+		enum BooleanToNumberConverter implements Converter<Boolean, Number> {
+			INSTANCE;
+
+			@Override
+			public Number convert(Boolean source) {
+				return source ? 1 : 0;
+			}
+		}
+
+		@ReadingConverter
+		enum NumberToBooleanConverter implements Converter<Number, Boolean> {
+			INSTANCE;
+
+			@Override
+			public Boolean convert(Number source) {
+				return source.intValue() == 0;
+			}
+		}
+
+		@WritingConverter
+		enum BooleanToYnConverter implements Converter<Boolean, String> {
+			INSTANCE;
+
+			@Override
+			public String convert(Boolean source) {
+				return source ? "Y" : "N";
+			}
+		}
+
 	}
 
 }

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/repository/query/PartTreeJdbcQueryUnitTests.java

@@ -27,6 +27,7 @@ import java.util.Date;
 import java.util.List;
 import java.util.Properties;
 
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.junit.jupiter.MockitoExtension;
@@ -457,7 +458,7 @@ public class PartTreeJdbcQueryUnitTests {
 		RelationalParametersParameterAccessor accessor = getAccessor(queryMethod, new Object[0]);
 		ParametrizedQuery query = jdbcQuery.createQuery(accessor, returnedType);
 
-		assertThat(query.getQuery()).isEqualTo(BASE_SELECT + " WHERE " + TABLE + ".\"ACTIVE\" = TRUE");
+		assertThat(query.getQuery()).isEqualTo(BASE_SELECT + " WHERE " + TABLE + ".\"ACTIVE\" = :active");
 	}
 
 	@Test // DATAJDBC-318
@@ -468,7 +469,7 @@ public class PartTreeJdbcQueryUnitTests {
 		RelationalParametersParameterAccessor accessor = getAccessor(queryMethod, new Object[0]);
 		ParametrizedQuery query = jdbcQuery.createQuery(accessor, returnedType);
 
-		assertThat(query.getQuery()).isEqualTo(BASE_SELECT + " WHERE " + TABLE + ".\"ACTIVE\" = FALSE");
+		assertThat(query.getQuery()).isEqualTo(BASE_SELECT + " WHERE " + TABLE + ".\"ACTIVE\" = :active");
 	}
 
 	@Test // DATAJDBC-318

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.repository/JdbcRepositoryIntegrationTests-db2.sql

@@ -5,5 +5,6 @@ CREATE TABLE dummy_entity
     id_Prop BIGINT GENERATED BY DEFAULT AS IDENTITY ( START WITH 1 ) PRIMARY KEY,
     NAME    VARCHAR(100),
     POINT_IN_TIME TIMESTAMP,
-    OFFSET_DATE_TIME TIMESTAMP -- with time zone is only supported with z/OS
+    OFFSET_DATE_TIME TIMESTAMP, -- with time zone is only supported with z/OS
+    FLAG BOOLEAN
 );

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.repository/JdbcRepositoryIntegrationTests-h2.sql

@@ -3,5 +3,6 @@ CREATE TABLE dummy_entity
     id_Prop BIGINT GENERATED BY DEFAULT AS IDENTITY ( START WITH 1 ) PRIMARY KEY,
     NAME    VARCHAR(100),
     POINT_IN_TIME TIMESTAMP,
-    OFFSET_DATE_TIME TIMESTAMP WITH TIME ZONE
+    OFFSET_DATE_TIME TIMESTAMP WITH TIME ZONE,
+    FLAG BOOLEAN
 );

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.repository/JdbcRepositoryIntegrationTests-hsql.sql

@@ -3,5 +3,6 @@ CREATE TABLE dummy_entity
     id_Prop BIGINT GENERATED BY DEFAULT AS IDENTITY ( START WITH 1 ) PRIMARY KEY,
     NAME    VARCHAR(100),
     POINT_IN_TIME TIMESTAMP,
-    OFFSET_DATE_TIME TIMESTAMP WITH TIME ZONE
+    OFFSET_DATE_TIME TIMESTAMP WITH TIME ZONE,
+    FLAG BOOLEAN
 );

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.repository/JdbcRepositoryIntegrationTests-mariadb.sql

@@ -3,5 +3,6 @@ CREATE TABLE dummy_entity
     id_Prop BIGINT AUTO_INCREMENT PRIMARY KEY,
     NAME    VARCHAR(100),
     POINT_IN_TIME TIMESTAMP(3),
-    OFFSET_DATE_TIME TIMESTAMP(3)
+    OFFSET_DATE_TIME TIMESTAMP(3),
+    FLAG BOOLEAN
 );

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.repository/JdbcRepositoryIntegrationTests-mssql.sql

@@ -4,5 +4,6 @@ CREATE TABLE dummy_entity
     id_Prop BIGINT IDENTITY PRIMARY KEY,
     NAME    VARCHAR(100),
     POINT_IN_TIME DATETIME,
-    OFFSET_DATE_TIME DATETIMEOFFSET
+    OFFSET_DATE_TIME DATETIMEOFFSET,
+    FLAG BIT
 );

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.repository/JdbcRepositoryIntegrationTests-mysql.sql

@@ -1,9 +1,10 @@
 SET SQL_MODE='ALLOW_INVALID_DATES';
 
-CREATE TABLE dummy_entity
+CREATE TABLE DUMMY_ENTITY
 (
-    id_Prop BIGINT AUTO_INCREMENT PRIMARY KEY,
+    ID_PROP BIGINT AUTO_INCREMENT PRIMARY KEY,
     NAME    VARCHAR(100),
-    POINT_IN_TIME TIMESTAMP(3) default null,
+    POINT_IN_TIME TIMESTAMP(3) DEFAULT NULL,
-    OFFSET_DATE_TIME TIMESTAMP(3) default null
+    OFFSET_DATE_TIME TIMESTAMP(3) DEFAULT NULL,
+    FLAG BIT(1)
 );

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.repository/JdbcRepositoryIntegrationTests-oracle.sql

@@ -5,5 +5,6 @@ CREATE TABLE DUMMY_ENTITY
     ID_PROP NUMBER GENERATED BY DEFAULT ON NULL AS IDENTITY PRIMARY KEY,
     NAME    VARCHAR2(100),
     POINT_IN_TIME TIMESTAMP,
-    OFFSET_DATE_TIME TIMESTAMP WITH TIME ZONE
+    OFFSET_DATE_TIME TIMESTAMP WITH TIME ZONE,
+    FLAG NUMBER(1,0)
 );

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.repository/JdbcRepositoryIntegrationTests-postgres.sql

@@ -4,5 +4,6 @@ CREATE TABLE dummy_entity
     id_Prop SERIAL PRIMARY KEY,
     NAME    VARCHAR(100),
     POINT_IN_TIME TIMESTAMP,
-    OFFSET_DATE_TIME TIMESTAMP WITH TIME ZONE
+    OFFSET_DATE_TIME TIMESTAMP WITH TIME ZONE,
+    FLAG BOOLEAN
 );

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/OracleDialect.java

@@ -15,9 +15,15 @@
  */
 package org.springframework.data.relational.core.dialect;
 
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.data.convert.ReadingConverter;
+import org.springframework.data.convert.WritingConverter;
+
 import java.util.Collection;
 import java.util.Collections;
 
+import static java.util.Arrays.*;
+
 /**
  * An SQL dialect for Oracle.
  *
@@ -47,7 +53,25 @@ public class OracleDialect extends AnsiDialect {
 
 	@Override
 	public Collection<Object> getConverters() {
-		return Collections.singletonList(TimestampAtUtcToOffsetDateTimeConverter.INSTANCE);
+		return asList(TimestampAtUtcToOffsetDateTimeConverter.INSTANCE, NumberToBooleanConverter.INSTANCE, BooleanToIntegerConverter.INSTANCE);
+	}
+
+	@ReadingConverter
+	enum NumberToBooleanConverter implements Converter<Number, Boolean> {
+		INSTANCE;
+
+		@Override
+		public Boolean convert(Number number) {
+			return number.intValue() != 0;
+		}
 	}
+	@WritingConverter
+	enum BooleanToIntegerConverter implements Converter<Boolean, Integer> {
+		INSTANCE;
 
+		@Override
+		public Integer convert(Boolean bool) {
+			return bool ? 1 : 0;
+		}
+	}
 }