[SPARK-16947][SQL] Support type coercion and foldable expression for inline tables

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala

@@ -107,6 +107,7 @@ class Analyzer(
       GlobalAggregates ::
       ResolveAggregateFunctions ::
       TimeWindowing ::
+      ResolveInlineTables ::
       TypeCoercion.typeCoercionRules ++
       extendedResolutionRules : _*),
     Batch("Nondeterministic", Once,

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/ResolveInlineTables.scala

@@ -0,0 +1,109 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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
+ *
+ *    http://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.apache.spark.sql.catalyst.analysis
+
+import org.apache.spark.sql.catalyst.InternalRow
+import org.apache.spark.sql.catalyst.expressions.Cast
+import org.apache.spark.sql.catalyst.plans.logical.{LocalRelation, LogicalPlan}
+import org.apache.spark.sql.catalyst.rules.Rule
+import org.apache.spark.sql.types.{StructField, StructType}
+
+/**
+ * An analyzer rule that replaces [[UnresolvedInlineTable]] with [[LocalRelation]].
+ */
+object ResolveInlineTables extends Rule[LogicalPlan] {
+  override def apply(plan: LogicalPlan): LogicalPlan = plan transformUp {
+    case table: UnresolvedInlineTable if table.expressionsResolved =>
+      validateInputDimension(table)
+      validateInputFoldable(table)
+      convert(table)
+  }
+
+  /**
+   * Validates that all inline table data are foldable expressions.
+   *
+   * This is publicly visible for unit testing.
+   */
+  def validateInputFoldable(table: UnresolvedInlineTable): Unit = {
+    table.rows.foreach { row =>
+      row.foreach { e =>
+        if (!e.resolved || !e.foldable) {
+          e.failAnalysis(s"cannot evaluate expression ${e.sql} in inline table definition")
+        }
+      }
+    }
+  }
+
+  /**
+   * Validates the input data dimension:
+   * 1. All rows have the same cardinality.
+   * 2. The number of column aliases defined is consistent with the number of columns in data.
+   *
+   * This is publicly visible for unit testing.
+   */
+  def validateInputDimension(table: UnresolvedInlineTable): Unit = {
+    if (table.rows.nonEmpty) {
+      val numCols = table.rows.head.size
+      table.rows.zipWithIndex.foreach { case (row, ri) =>
+        if (row.size != numCols) {
+          table.failAnalysis(s"expected $numCols columns but found ${row.size} columns in row $ri")
+        }
+      }
+
+      if (table.names.size != numCols) {
+        table.failAnalysis(s"expected ${table.names.size} columns but found $numCols in first row")
+      }
+    }
+  }
+
+  /**
+   * Convert a valid (with right shape and foldable inputs) [[UnresolvedInlineTable]]
+   * into a [[LocalRelation]].
+   *
+   * This function attempts to coerce inputs into consistent types.
+   *
+   * This is publicly visible for unit testing.
+   */
+  def convert(table: UnresolvedInlineTable): LocalRelation = {
+    val numCols = table.rows.head.size
+
+    // For each column, traverse all the values and find a common data type.
+    val targetTypes = Seq.tabulate(numCols) { ci =>
+      val inputTypes = table.rows.map(_(ci).dataType)
+      TypeCoercion.findWiderTypeWithoutStringPromotion(inputTypes).getOrElse {
+        table.failAnalysis(s"incompatible types found in column $ci for inline table")
+      }
+    }
+    assert(targetTypes.size == table.names.size)
+
+    val newRows: Seq[InternalRow] = table.rows.map { row =>
+      InternalRow.fromSeq(row.zipWithIndex.map { case (e, ci) =>
+        val targetType = targetTypes(ci)
+        if (e.dataType.sameType(targetType)) {
+          e.eval()
+        } else {
+          Cast(e, targetType).eval()
+        }
+      })
+    }
+
+    val attributes = StructType(targetTypes.zip(table.names)
+      .map { case (typ, name) => StructField(name, typ) }).toAttributes
+    LocalRelation(attributes, newRows)
+  }
+}

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/TypeCoercion.scala

@@ -150,7 +150,7 @@ object TypeCoercion {
    * [[findTightestCommonType]], but can handle decimal types. If the wider decimal type exceeds
    * system limitation, this rule will truncate the decimal type before return it.
    */
-  private def findWiderTypeWithoutStringPromotion(types: Seq[DataType]): Option[DataType] = {
+  def findWiderTypeWithoutStringPromotion(types: Seq[DataType]): Option[DataType] = {
     types.foldLeft[Option[DataType]](Some(NullType))((r, c) => r match {
       case Some(d) => findTightestCommonTypeOfTwo(d, c).orElse((d, c) match {
         case (t1: DecimalType, t2: DecimalType) =>

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/unresolved.scala

@@ -49,6 +49,23 @@ case class UnresolvedRelation(
   override lazy val resolved = false
 }
 
+/**
+ * An inline table that has not been resolved yet. Once resolved, it is turned by the analyzer into
+ * a [[org.apache.spark.sql.catalyst.plans.logical.LocalRelation]].
+ *
+ * @param names list of column names
+ * @param rows expressions for the data
+ */
+case class UnresolvedInlineTable(
+    names: Seq[String],
+    rows: Seq[Seq[Expression]])
+  extends LeafNode {
+
+  lazy val expressionsResolved: Boolean = rows.forall(_.forall(_.resolved))
+  override def output: Seq[Attribute] = Nil
+  override lazy val resolved = false
+}
+
 /**
  * Holds the name of an attribute that has yet to be resolved.
  */

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/parser/AstBuilder.scala

@@ -662,39 +662,21 @@ class AstBuilder extends SqlBaseBaseVisitor[AnyRef] with Logging {
    */
   override def visitInlineTable(ctx: InlineTableContext): LogicalPlan = withOrigin(ctx) {
     // Get the backing expressions.
-    val expressions = ctx.expression.asScala.map { eCtx =>
-      val e = expression(eCtx)
-      validate(e.foldable, "All expressions in an inline table must be constants.", eCtx)
-      e
-    }
-
-    // Validate and evaluate the rows.
-    val (structType, structConstructor) = expressions.head.dataType match {
-      case st: StructType =>
-        (st, (e: Expression) => e)
-      case dt =>
-        val st = CreateStruct(Seq(expressions.head)).dataType
-        (st, (e: Expression) => CreateStruct(Seq(e)))
-    }
-    val rows = expressions.map {
-      case expression =>
-        val safe = Cast(structConstructor(expression), structType)
-        safe.eval().asInstanceOf[InternalRow]
+    val rows = ctx.expression.asScala.map { e =>
+      expression(e) match {
+        case CreateStruct(children) => children
+        case child => Seq(child)
+      }
     }
 
-    // Construct attributes.
-    val baseAttributes = structType.toAttributes.map(_.withNullability(true))
-    val attributes = if (ctx.identifierList != null) {
-      val aliases = visitIdentifierList(ctx.identifierList)
-      validate(aliases.size == baseAttributes.size,
-        "Number of aliases must match the number of fields in an inline table.", ctx)
-      baseAttributes.zip(aliases).map(p => p._1.withName(p._2))
+    val aliases = if (ctx.identifierList != null) {
+      visitIdentifierList(ctx.identifierList)
     } else {
-      baseAttributes
+      Seq.tabulate(rows.head.size)(i => s"col${i + 1}")
     }
 
-    // Create plan and add an alias if a name has been defined.
-    LocalRelation(attributes, rows).optionalMap(ctx.identifier)(aliasPlan)
+    val table = UnresolvedInlineTable(aliases, rows)
+    table.optionalMap(ctx.identifier)(aliasPlan)
   }
 
   /**

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/analysis/ResolveInlineTablesSuite.scala

@@ -0,0 +1,84 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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
+ *
+ *    http://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.apache.spark.sql.catalyst.analysis
+
+import org.scalatest.BeforeAndAfter
+
+import org.apache.spark.sql.AnalysisException
+import org.apache.spark.sql.catalyst.expressions.{Literal, Rand}
+import org.apache.spark.sql.catalyst.plans.PlanTest
+import org.apache.spark.sql.types.LongType
+
+/**
+ * Unit tests for [[ResolveInlineTables]]. Note that there are also test cases defined in
+ * end-to-end tests (in sql/core module) for verifying the correct error messages are shown
+ * in negative cases.
+ */
+class ResolveInlineTablesSuite extends PlanTest with BeforeAndAfter {
+
+  private def lit(v: Any): Literal = Literal(v)
+
+  test("validate inputs are foldable") {
+    ResolveInlineTables.validateInputFoldable(
+      UnresolvedInlineTable(Seq("c1", "c2"), Seq(Seq(lit(1)))))
+
+    // nondeterministic (rand)
+    intercept[AnalysisException] {
+      ResolveInlineTables.validateInputFoldable(
+        UnresolvedInlineTable(Seq("c1", "c2"), Seq(Seq(Rand(1)))))
+    }
+
+    // unresolved attribute
+    intercept[AnalysisException] {
+      ResolveInlineTables.validateInputFoldable(
+        UnresolvedInlineTable(Seq("c1", "c2"), Seq(Seq(UnresolvedAttribute("A")))))
+    }
+  }
+
+  test("validate input dimensions") {
+    ResolveInlineTables.validateInputDimension(
+      UnresolvedInlineTable(Seq("c1"), Seq(Seq(lit(1)), Seq(lit(2)))))
+
+    // num alias != data dimension
+    intercept[AnalysisException] {
+      ResolveInlineTables.validateInputDimension(
+        UnresolvedInlineTable(Seq("c1", "c2"), Seq(Seq(lit(1)), Seq(lit(2)))))
+    }
+
+    // num alias == data dimension, but data themselves are inconsistent
+    intercept[AnalysisException] {
+      ResolveInlineTables.validateInputDimension(
+        UnresolvedInlineTable(Seq("c1"), Seq(Seq(lit(1)), Seq(lit(21), lit(22)))))
+    }
+  }
+
+  test("do not fire the rule if not all expressions are resolved") {
+    val table = UnresolvedInlineTable(Seq("c1", "c2"), Seq(Seq(UnresolvedAttribute("A"))))
+    assert(ResolveInlineTables(table) == table)
+  }
+
+  test("convert") {
+    val table = UnresolvedInlineTable(Seq("c1"), Seq(Seq(lit(1)), Seq(lit(2L))))
+    val converted = ResolveInlineTables.convert(table)
+
+    assert(converted.output.map(_.dataType) == Seq(LongType))
+    assert(converted.data.size == 2)
+    assert(converted.data(0).getLong(0) == 1L)
+    assert(converted.data(1).getLong(0) == 2L)
+  }
+}

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/PlanParserSuite.scala

@@ -19,7 +19,7 @@ package org.apache.spark.sql.catalyst.parser
 
 import org.apache.spark.sql.Row
 import org.apache.spark.sql.catalyst.FunctionIdentifier
-import org.apache.spark.sql.catalyst.analysis.UnresolvedGenerator
+import org.apache.spark.sql.catalyst.analysis.{UnresolvedGenerator, UnresolvedInlineTable}
 import org.apache.spark.sql.catalyst.expressions._
 import org.apache.spark.sql.catalyst.plans._
 import org.apache.spark.sql.catalyst.plans.logical._
@@ -427,19 +427,14 @@ class PlanParserSuite extends PlanTest {
   }
 
   test("inline table") {
-    assertEqual("values 1, 2, 3, 4", LocalRelation.fromExternalRows(
-      Seq('col1.int),
-      Seq(1, 2, 3, 4).map(x => Row(x))))
+    assertEqual("values 1, 2, 3, 4",
+      UnresolvedInlineTable(Seq("col1"), Seq(1, 2, 3, 4).map(x => Seq(Literal(x)))))
+
     assertEqual(
-      "values (1, 'a'), (2, 'b'), (3, 'c') as tbl(a, b)",
-      LocalRelation.fromExternalRows(
-        Seq('a.int, 'b.string),
-        Seq((1, "a"), (2, "b"), (3, "c")).map(x => Row(x._1, x._2))).as("tbl"))
-    intercept("values (a, 'a'), (b, 'b')",
-      "All expressions in an inline table must be constants.")
-    intercept("values (1, 'a'), (2, 'b') as tbl(a, b, c)",
-      "Number of aliases must match the number of fields in an inline table.")
-    intercept[ArrayIndexOutOfBoundsException](parsePlan("values (1, 'a'), (2, 'b', 5Y)"))
+      "values (1, 'a'), (2, 'b') as tbl(a, b)",
+      UnresolvedInlineTable(
+        Seq("a", "b"),
+        Seq(Literal(1), Literal("a")) :: Seq(Literal(2), Literal("b")) :: Nil).as("tbl"))
   }
 
   test("simple select query with !> and !<") {

sql/core/src/test/resources/sql-tests/inputs/inline-table.sql

@@ -0,0 +1,39 @@
+
+-- single row, without table and column alias
+select * from values ("one", 1);
+
+-- single row, without column alias
+select * from values ("one", 1) as data;
+
+-- single row
+select * from values ("one", 1) as data(a, b);
+
+-- two rows
+select * from values ("one", 1), ("two", 2) as data(a, b);
+
+-- int and long coercion
+select * from values ("one", 1), ("two", 2L) as data(a, b);
+
+-- foldable expressions
+select * from values ("one", 1 + 0), ("two", 1 + 3L) as data(a, b);
+
+-- complex types
+select * from values ("one", array(0, 1)), ("two", array(2, 3)) as data(a, b);
+
+-- decimal and double coercion
+select * from values ("one", 2.0), ("two", 3.0D) as data(a, b);
+
+-- error reporting: different number of columns
+select * from values ("one", 2.0), ("two") as data(a, b);
+
+-- error reporting: types that are incompatible
+select * from values ("one", array(0, 1)), ("two", struct(1, 2)) as data(a, b);
+
+-- error reporting: number aliases different from number data values
+select * from values ("one"), ("two") as data(a, b);
+
+-- error reporting: unresolved expression
+select * from values ("one", random_not_exist_func(1)), ("two", 2) as data(a, b);
+
+-- error reporting: aggregate expression
+select * from values ("one", count(1)), ("two", 2) as data(a, b);