From 87d49cbcb1b9003763148dec6a3b067cf86f6ab3 Mon Sep 17 00:00:00 2001
From: PengLei <peng.8lei@gmail.com>
Date: Wed, 4 Aug 2021 10:04:13 +0900
Subject: [PATCH] [SPARK-36381][SQL] Add case sensitive and case insensitive
 compare for checking column name exist when alter table

### What changes were proposed in this pull request?
Add the Resolver to `checkColumnNotExists` to check name exist in case sensitive.

### Why are the changes needed?
At now the resolver is `_ == _` of `findNestedField`  called by `checkColumnNotExists`
Add `alter.conf.resolver` to it.
[SPARK-36381](https://issues.apache.org/jira/browse/SPARK-36381)
### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
Add ut tests

Closes #33618 from Peng-Lei/sensitive-cloumn-name.

Authored-by: PengLei <peng.8lei@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
---
 .../sql/catalyst/analysis/CheckAnalysis.scala |  9 ++++----
 .../V2CommandsCaseSensitivitySuite.scala      | 22 +++++++++++++++++++
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/CheckAnalysis.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/CheckAnalysis.scala
index 09cd71b4eb..043bf95943 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/CheckAnalysis.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/CheckAnalysis.scala
@@ -940,8 +940,9 @@ trait CheckAnalysis extends PredicateHelper with LookupCatalog {
    * Validates the options used for alter table commands after table and columns are resolved.
    */
   private def checkAlterTableCommand(alter: AlterTableCommand): Unit = {
-    def checkColumnNotExists(op: String, fieldNames: Seq[String], struct: StructType): Unit = {
-      if (struct.findNestedField(fieldNames, includeCollections = true).isDefined) {
+    def checkColumnNotExists(
+      op: String, fieldNames: Seq[String], struct: StructType, r: Resolver): Unit = {
+      if (struct.findNestedField(fieldNames, includeCollections = true, r).isDefined) {
         alter.failAnalysis(s"Cannot $op column, because ${fieldNames.quoted} " +
           s"already exists in ${struct.treeString}")
       }
@@ -950,7 +951,7 @@ trait CheckAnalysis extends PredicateHelper with LookupCatalog {
     alter match {
       case AddColumns(table: ResolvedTable, colsToAdd) =>
         colsToAdd.foreach { colToAdd =>
-          checkColumnNotExists("add", colToAdd.name, table.schema)
+          checkColumnNotExists("add", colToAdd.name, table.schema, alter.conf.resolver)
         }
         SchemaUtils.checkColumnNameDuplication(
           colsToAdd.map(_.name.quoted),
@@ -958,7 +959,7 @@ trait CheckAnalysis extends PredicateHelper with LookupCatalog {
           alter.conf.resolver)
 
       case RenameColumn(table: ResolvedTable, col: ResolvedFieldName, newName) =>
-        checkColumnNotExists("rename", col.path :+ newName, table.schema)
+        checkColumnNotExists("rename", col.path :+ newName, table.schema, alter.conf.resolver)
 
       case a @ AlterColumn(table: ResolvedTable, col: ResolvedFieldName, _, _, _, _) =>
         val fieldName = col.name.quoted
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/connector/V2CommandsCaseSensitivitySuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/connector/V2CommandsCaseSensitivitySuite.scala
index 1d6e0a8ef4..0cc8d05361 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/connector/V2CommandsCaseSensitivitySuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/connector/V2CommandsCaseSensitivitySuite.scala
@@ -249,6 +249,28 @@ class V2CommandsCaseSensitivitySuite extends SharedSparkSession with AnalysisTes
       expectErrorOnCaseSensitive = false)
   }
 
+  test("SPARK-36381: Check column name exist case sensitive and insensitive when add column") {
+    alterTableTest(
+      AddColumns(
+        table,
+        Seq(QualifiedColType(
+          None,
+          "ID",
+          LongType,
+          true,
+          None,
+          Some(UnresolvedFieldPosition(ColumnPosition.after("id")))))),
+      Seq("Cannot add column, because ID already exists in root"),
+      expectErrorOnCaseSensitive = false)
+  }
+
+  test("SPARK-36381: Check column name exist case sensitive and insensitive when rename column") {
+    alterTableTest(
+      RenameColumn(table, UnresolvedFieldName(Array("id")), "DATA"),
+      Seq("Cannot rename column, because DATA already exists in root"),
+      expectErrorOnCaseSensitive = false)
+  }
+
   test("AlterTable: drop column resolution") {
     Seq(Array("ID"), Array("point", "X"), Array("POINT", "X"), Array("POINT", "x")).foreach { ref =>
       alterTableTest(