Add virtual columns support.

README.md

@@ -229,6 +229,9 @@ Supported Features
 * ThetaSketchEstimate
 * ThetaSketchSetOp
 
+#### Virtual Columns
+* Expression
+
 #### Granularity
 * Duration
 * Period

src/main/java/in/zapr/druid/druidry/query/aggregation/DruidAggregationQuery.java

@@ -26,6 +26,7 @@
 import in.zapr.druid.druidry.granularity.Granularity;
 import in.zapr.druid.druidry.postAggregator.DruidPostAggregator;
 import in.zapr.druid.druidry.query.DruidQuery;
+import in.zapr.druid.druidry.virtualColumn.DruidVirtualColumn;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 
@@ -35,6 +36,7 @@
 public abstract class DruidAggregationQuery extends DruidQuery {
  protected List<Interval> intervals;
  protected Granularity granularity;
+ protected List<DruidVirtualColumn> virtualColumns;
  protected DruidFilter filter;
  protected List<DruidAggregator> aggregations;
  protected List<DruidPostAggregator> postAggregations;

src/main/java/in/zapr/druid/druidry/query/aggregation/DruidGroupByQuery.java

@@ -29,6 +29,7 @@
 import in.zapr.druid.druidry.limitSpec.DefaultLimitSpec;
 import in.zapr.druid.druidry.postAggregator.DruidPostAggregator;
 import in.zapr.druid.druidry.query.QueryType;
+import in.zapr.druid.druidry.virtualColumn.DruidVirtualColumn;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -50,6 +51,7 @@ private DruidGroupByQuery(@NonNull String dataSource,
  @NonNull List<DruidDimension> dimensions,
  DefaultLimitSpec limitSpec,
  @NonNull Granularity granularity,
+ List<DruidVirtualColumn> virtualColumns,
  DruidFilter filter,
  List<DruidAggregator> aggregators,
  List<DruidPostAggregator> postAggregators,
@@ -61,10 +63,11 @@ private DruidGroupByQuery(@NonNull String dataSource,
  this.dimensions = dimensions;
  this.limitSpec = limitSpec;
  this.granularity = granularity;
+ this.virtualColumns = virtualColumns;
  this.filter = filter;
  this.aggregations = aggregators;
  this.postAggregations = postAggregators;
  this.intervals = intervals;
  this.context = context;
  }
-}
+}

src/main/java/in/zapr/druid/druidry/query/aggregation/DruidTimeSeriesQuery.java

@@ -27,6 +27,7 @@
 import in.zapr.druid.druidry.granularity.Granularity;
 import in.zapr.druid.druidry.postAggregator.DruidPostAggregator;
 import in.zapr.druid.druidry.query.QueryType;
+import in.zapr.druid.druidry.virtualColumn.DruidVirtualColumn;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -42,6 +43,7 @@ public class DruidTimeSeriesQuery extends DruidAggregationQuery {
  @Builder
  private DruidTimeSeriesQuery(@NonNull String dataSource, Boolean descending,
  @NonNull List<Interval> intervals, @NonNull Granularity granularity,
+ List<DruidVirtualColumn> virtualColumns,
  DruidFilter filter, List<DruidAggregator> aggregators,
  List<DruidPostAggregator> postAggregators, Context context) {
 
@@ -50,6 +52,7 @@ private DruidTimeSeriesQuery(@NonNull String dataSource, Boolean descending,
  this.descending = descending;
  this.intervals = intervals;
  this.granularity = granularity;
+ this.virtualColumns = virtualColumns;
  this.filter = filter;
  this.aggregations = aggregators;
  this.postAggregations = postAggregators;

src/main/java/in/zapr/druid/druidry/query/aggregation/DruidTopNQuery.java

@@ -31,6 +31,7 @@
 import in.zapr.druid.druidry.postAggregator.DruidPostAggregator;
 import in.zapr.druid.druidry.query.QueryType;
 import in.zapr.druid.druidry.topNMetric.TopNMetric;
+import in.zapr.druid.druidry.virtualColumn.DruidVirtualColumn;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -49,6 +50,7 @@ public class DruidTopNQuery extends DruidAggregationQuery {
  private DruidTopNQuery(@NonNull String dataSource,
  @NonNull List<Interval> intervals,
  @NonNull Granularity granularity,
+ List<DruidVirtualColumn> virtualColumns,
  DruidFilter filter,
  List<DruidAggregator> aggregators,
  List<DruidPostAggregator> postAggregators,
@@ -61,6 +63,7 @@ private DruidTopNQuery(@NonNull String dataSource,
  this.dataSource = dataSource;
  this.intervals = intervals;
  this.granularity = granularity;
+ this.virtualColumns = virtualColumns;
  this.filter = filter;
  this.aggregations = aggregators;
  this.postAggregations = postAggregators;

src/main/java/in/zapr/druid/druidry/virtualColumn/DruidVirtualColumn.java

@@ -0,0 +1,18 @@
+package in.zapr.druid.druidry.virtualColumn;
+
+import in.zapr.druid.druidry.dimension.enums.OutputType;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NonNull;
+
+@Getter
+@EqualsAndHashCode
+public abstract class DruidVirtualColumn {
+ @NonNull
+ protected String type;
+
+ @NonNull
+ protected String name;
+
+ protected OutputType outputType;
+}

src/main/java/in/zapr/druid/druidry/virtualColumn/ExpressionVirtualColumn.java

@@ -0,0 +1,28 @@
+package in.zapr.druid.druidry.virtualColumn;
+
+import javax.annotation.Nonnull;
+
+import in.zapr.druid.druidry.dimension.enums.OutputType;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NonNull;
+
+@Getter
+@EqualsAndHashCode(callSuper = true)
+public class ExpressionVirtualColumn extends DruidVirtualColumn {
+ private static final String EXPRESSION_VIRTUAL_COLUMN = "expression";
+
+ @NonNull
+ private String expression;
+
+ public ExpressionVirtualColumn(@NonNull String name, @Nonnull String expression) {
+ this(name, expression, OutputType.FLOAT);
+ }
+
+ public ExpressionVirtualColumn(@NonNull String name, @Nonnull String expression, OutputType outputType) {
+ this.type = EXPRESSION_VIRTUAL_COLUMN;
+ this.name = name;
+ this.outputType = outputType;
+ this.expression = expression;
+ }
+}

src/test/java/in/zapr/druid/druidry/virtualColumn/ExpressionVirtualColumnTest.java

@@ -0,0 +1,45 @@
+package in.zapr.druid.druidry.virtualColumn;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+import org.skyscreamer.jsonassert.JSONAssert;
+import org.skyscreamer.jsonassert.JSONCompareMode;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+import in.zapr.druid.druidry.dimension.enums.OutputType;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+public class ExpressionVirtualColumnTest {
+ private static ObjectMapper objectMapper;
+
+ @BeforeClass
+ public void init() {
+ objectMapper = new ObjectMapper();
+ }
+
+ @Test
+ public void testGeneratedJSON() throws JsonProcessingException, JSONException {
+ ExpressionVirtualColumn column = new ExpressionVirtualColumn("foo", "a + b");
+ JSONObject expected = new JSONObject();
+ expected.put("type", "expression");
+ expected.put("name", "foo");
+ expected.put("outputType", "FLOAT");
+ expected.put("expression", "a + b");
+ String output = objectMapper.writeValueAsString(column);
+ JSONAssert.assertEquals(expected.toString(), output, JSONCompareMode.NON_EXTENSIBLE);
+
+ column = new ExpressionVirtualColumn("bar", "a + b", OutputType.LONG);
+ expected = new JSONObject();
+ expected.put("type", "expression");
+ expected.put("name", "bar");
+ expected.put("outputType", "LONG");
+ expected.put("expression", "a + b");
+ output = objectMapper.writeValueAsString(column);
+ JSONAssert.assertEquals(expected.toString(), output, JSONCompareMode.NON_EXTENSIBLE);
+ }
+}