[SPARK-51839] Support except(All)?/intersect(All)?/union(All)?/unionByName in DataFrame

### What changes were proposed in this pull request?

This PR aims to support seven `Set`-related `DataFrame` APIs.
- `except`
- `exceptAll`
- `intersect`
- `intersectAll`
- `union`
- `unionAll`
- `unionByName`

### Why are the changes needed?

For feature parity.

### Does this PR introduce _any_ user-facing change?

No, this is a new addition to the unreleased version.

### How was this patch tested?

Pass the CIs.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #68 from dongjoon-hyun/SPARK-51839.

Authored-by: Dongjoon Hyun <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: dongjoon-hyun

Sources/SparkConnect/DataFrame.swift

@@ -522,6 +522,87 @@ public actor DataFrame: Sendable {
     }
   }
 
+  /// Returns a new `DataFrame` containing rows in this `DataFrame` but not in another `DataFrame`.
+  /// This is equivalent to `EXCEPT DISTINCT` in SQL.
+  /// - Parameter other: A `DataFrame` to exclude.
+  /// - Returns: A `DataFrame`.
+  public func except(_ other: DataFrame) async -> DataFrame {
+    let right = await (other.getPlan() as! Plan).root
+    let plan = SparkConnectClient.getSetOperation(self.plan.root, right, SetOpType.except)
+    return DataFrame(spark: self.spark, plan: plan)
+  }
+
+  /// Returns a new `DataFrame` containing rows in this `DataFrame` but not in another `DataFrame` while
+  /// preserving the duplicates. This is equivalent to `EXCEPT ALL` in SQL.
+  /// - Parameter other: A `DataFrame` to exclude.
+  /// - Returns: A `DataFrame`.
+  public func exceptAll(_ other: DataFrame) async -> DataFrame {
+    let right = await (other.getPlan() as! Plan).root
+    let plan = SparkConnectClient.getSetOperation(self.plan.root, right, SetOpType.except, isAll: true)
+    return DataFrame(spark: self.spark, plan: plan)
+  }
+
+  /// Returns a new `DataFrame` containing rows only in both this `DataFrame` and another `DataFrame`.
+  /// This is equivalent to `INTERSECT` in SQL.
+  /// - Parameter other: A `DataFrame` to intersect with.
+  /// - Returns: A `DataFrame`.
+  public func intersect(_ other: DataFrame) async -> DataFrame {
+    let right = await (other.getPlan() as! Plan).root
+    let plan = SparkConnectClient.getSetOperation(self.plan.root, right, SetOpType.intersect)
+    return DataFrame(spark: self.spark, plan: plan)
+  }
+
+  /// Returns a new `DataFrame` containing rows only in both this `DataFrame` and another `DataFrame` while
+  /// preserving the duplicates. This is equivalent to `INTERSECT ALL` in SQL.
+  /// - Parameter other: A `DataFrame` to intersect with.
+  /// - Returns: A `DataFrame`.
+  public func intersectAll(_ other: DataFrame) async -> DataFrame {
+    let right = await (other.getPlan() as! Plan).root
+    let plan = SparkConnectClient.getSetOperation(self.plan.root, right, SetOpType.intersect, isAll: true)
+    return DataFrame(spark: self.spark, plan: plan)
+  }
+
+  /// Returns a new `DataFrame` containing union of rows in this `DataFrame` and another `DataFrame`.
+  /// This is equivalent to `UNION ALL` in SQL. To do a SQL-style set union (that does
+  /// deduplication of elements), use this function followed by a [[distinct]].
+  /// Also as standard in SQL, this function resolves columns by position (not by name)
+  /// - Parameter other: A `DataFrame` to union with.
+  /// - Returns: A `DataFrame`.
+  public func union(_ other: DataFrame) async -> DataFrame {
+    let right = await (other.getPlan() as! Plan).root
+    let plan = SparkConnectClient.getSetOperation(self.plan.root, right, SetOpType.union, isAll: true)
+    return DataFrame(spark: self.spark, plan: plan)
+  }
+
+  /// Returns a new `DataFrame` containing union of rows in this `DataFrame` and another `DataFrame`.
+  /// This is an alias of `union`.
+  /// - Parameter other: A `DataFrame` to union with.
+  /// - Returns: A `DataFrame`.
+  public func unionAll(_ other: DataFrame) async -> DataFrame {
+    return await union(other)
+  }
+
+  /// Returns a new `DataFrame` containing union of rows in this `DataFrame` and another `DataFrame`.
+  /// The difference between this function and [[union]] is that this function resolves columns by
+  /// name (not by position).
+  /// When the parameter `allowMissingColumns` is `true`, the set of column names in this and other
+  /// `DataFrame` can differ; missing columns will be filled with null. Further, the missing columns
+  /// of this `DataFrame` will be added at the end in the schema of the union result
+  /// - Parameter other: A `DataFrame` to union with.
+  /// - Returns: A `DataFrame`.
+  public func unionByName(_ other: DataFrame, _ allowMissingColumns: Bool = false) async -> DataFrame {
+    let right = await (other.getPlan() as! Plan).root
+    let plan = SparkConnectClient.getSetOperation(
+      self.plan.root,
+      right,
+      SetOpType.union,
+      isAll: true,
+      byName: true,
+      allowMissingColumns: allowMissingColumns
+    )
+    return DataFrame(spark: self.spark, plan: plan)
+  }
+
   /// Returns a ``DataFrameWriter`` that can be used to write non-streaming data.
   public var write: DataFrameWriter {
     get {

Sources/SparkConnect/SparkConnectClient.swift

@@ -538,4 +538,22 @@ public actor SparkConnectClient {
       return response.jsonToDdl.ddlString
     }
   }
+
+  static func getSetOperation(
+    _ left: Relation, _ right: Relation, _ opType: SetOpType, isAll: Bool = false,
+    byName: Bool = false, allowMissingColumns: Bool = false
+  ) -> Plan {
+    var setOp = SetOperation()
+    setOp.leftInput = left
+    setOp.rightInput = right
+    setOp.setOpType = opType
+    setOp.isAll = isAll
+    setOp.allowMissingColumns = allowMissingColumns
+    setOp.byName = byName
+    var relation = Relation()
+    relation.setOp = setOp
+    var plan = Plan()
+    plan.opType = .root(relation)
+    return plan
+  }
 }

Sources/SparkConnect/TypeAliases.swift

@@ -42,6 +42,8 @@ typealias Read = Spark_Connect_Read
 typealias Relation = Spark_Connect_Relation
 typealias Sample = Spark_Connect_Sample
 typealias SaveMode = Spark_Connect_WriteOperation.SaveMode
+typealias SetOperation = Spark_Connect_SetOperation
+typealias SetOpType = SetOperation.SetOpType
 typealias SparkConnectService = Spark_Connect_SparkConnectService
 typealias Sort = Spark_Connect_Sort
 typealias StructType = Spark_Connect_DataType.Struct

Tests/SparkConnectTests/DataFrameTests.swift

@@ -376,6 +376,86 @@ struct DataFrameTests {
     #expect(try await df.unpersist().count() == 30)
     await spark.stop()
   }
+
+  @Test
+  func except() async throws {
+    let spark = try await SparkSession.builder.getOrCreate()
+    let df = try await spark.range(1, 3)
+    #expect(try await df.except(spark.range(1, 5)).collect() == [])
+    #expect(try await df.except(spark.range(2, 5)).collect() == [Row("1")])
+    #expect(try await df.except(spark.range(3, 5)).collect() == [Row("1"), Row("2")])
+    #expect(try await spark.sql("SELECT * FROM VALUES 1, 1").except(df).count() == 0)
+    await spark.stop()
+  }
+
+  @Test
+  func exceptAll() async throws {
+    let spark = try await SparkSession.builder.getOrCreate()
+    let df = try await spark.range(1, 3)
+    #expect(try await df.exceptAll(spark.range(1, 5)).collect() == [])
+    #expect(try await df.exceptAll(spark.range(2, 5)).collect() == [Row("1")])
+    #expect(try await df.exceptAll(spark.range(3, 5)).collect() == [Row("1"), Row("2")])
+    #expect(try await spark.sql("SELECT * FROM VALUES 1, 1").exceptAll(df).count() == 1)
+    await spark.stop()
+  }
+
+  @Test
+  func intersect() async throws {
+    let spark = try await SparkSession.builder.getOrCreate()
+    let df = try await spark.range(1, 3)
+    #expect(try await df.intersect(spark.range(1, 5)).collect() == [Row("1"), Row("2")])
+    #expect(try await df.intersect(spark.range(2, 5)).collect() == [Row("2")])
+    #expect(try await df.intersect(spark.range(3, 5)).collect() == [])
+    let df2 = try await spark.sql("SELECT * FROM VALUES 1, 1")
+    #expect(try await df2.intersect(df2).count() == 1)
+    await spark.stop()
+  }
+
+  @Test
+  func intersectAll() async throws {
+    let spark = try await SparkSession.builder.getOrCreate()
+    let df = try await spark.range(1, 3)
+    #expect(try await df.intersectAll(spark.range(1, 5)).collect() == [Row("1"), Row("2")])
+    #expect(try await df.intersectAll(spark.range(2, 5)).collect() == [Row("2")])
+    #expect(try await df.intersectAll(spark.range(3, 5)).collect() == [])
+    let df2 = try await spark.sql("SELECT * FROM VALUES 1, 1")
+    #expect(try await df2.intersectAll(df2).count() == 2)
+    await spark.stop()
+  }
+
+  @Test
+  func union() async throws {
+    let spark = try await SparkSession.builder.getOrCreate()
+    let df = try await spark.range(1, 2)
+    #expect(try await df.union(spark.range(1, 3)).collect() == [Row("1"), Row("1"), Row("2")])
+    #expect(try await df.union(spark.range(2, 3)).collect() == [Row("1"), Row("2")])
+    let df2 = try await spark.sql("SELECT * FROM VALUES 1, 1")
+    #expect(try await df2.union(df2).count() == 4)
+    await spark.stop()
+  }
+
+  @Test
+  func unionAll() async throws {
+    let spark = try await SparkSession.builder.getOrCreate()
+    let df = try await spark.range(1, 2)
+    #expect(try await df.unionAll(spark.range(1, 3)).collect() == [Row("1"), Row("1"), Row("2")])
+    #expect(try await df.unionAll(spark.range(2, 3)).collect() == [Row("1"), Row("2")])
+    let df2 = try await spark.sql("SELECT * FROM VALUES 1, 1")
+    #expect(try await df2.unionAll(df2).count() == 4)
+    await spark.stop()
+  }
+
+  @Test
+  func unionByName() async throws {
+    let spark = try await SparkSession.builder.getOrCreate()
+    let df1 = try await spark.sql("SELECT 1 a, 2 b")
+    let df2 = try await spark.sql("SELECT 4 b, 3 a")
+    #expect(try await df1.unionByName(df2).collect() == [Row("1", "2"), Row("3", "4")])
+    #expect(try await df1.union(df2).collect() == [Row("1", "2"), Row("4", "3")])
+    let df3 = try await spark.sql("SELECT * FROM VALUES 1, 1")
+    #expect(try await df3.unionByName(df3).count() == 4)
+    await spark.stop()
+  }
 #endif
 
   @Test