Apply code review comments

- Use SparkUnsupportedOperationException
- Remove unused string interpolation
- Fix indentation

Author: EnricoMi

common/utils/src/main/resources/error/error-conditions.json

@@ -6046,6 +6046,11 @@
           "Update column nullability for MySQL and MS SQL Server."
         ]
       },
+      "UPSERT" : {
+        "message" : [
+          "Upsert not supported by JDBC dialect <class>."
+        ]
+      },
       "WRITE_FOR_BINARY_SOURCE" : {
         "message" : [
           "Write for the binary file data source."

connector/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/UpsertTests.scala

@@ -31,8 +31,8 @@ trait UpsertTests {
   def createTableOption: String
   def upsertTestOptions: Map[String, String] = Map("createTableOptions" -> createTableOption)
 
-  test(s"Upsert existing table") { doTestUpsert(tableExists = true) }
-  test(s"Upsert non-existing table") { doTestUpsert(tableExists = false) }
+  test("Upsert existing table") { doTestUpsert(tableExists = true) }
+  test("Upsert non-existing table") { doTestUpsert(tableExists = false) }
 
   Seq(
     Seq("ts", "id", "v1", "v2"),
@@ -80,7 +80,7 @@ trait UpsertTests {
     assert(actual === expected)
   }
 
-  test(s"Upsert concurrency") {
+  test("Upsert concurrency") {
     // create a table with 100k rows
     val init =
       spark.range(100000)

sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/jdbc/JdbcUtils.scala

@@ -145,12 +145,12 @@ object JdbcUtils extends Logging with SQLConfHelper {
   }
 
   def getUpsertStatement(
-    table: String,
-    rddSchema: StructType,
-    tableSchema: Option[StructType],
-    isCaseSensitive: Boolean,
-    dialect: JdbcDialect,
-    options: JDBCOptions): String = {
+      table: String,
+      rddSchema: StructType,
+      tableSchema: Option[StructType],
+      isCaseSensitive: Boolean,
+      dialect: JdbcDialect,
+      options: JDBCOptions): String = {
     val columns = getInsertColumns(table, rddSchema, tableSchema, isCaseSensitive, dialect)
     dialect.getUpsertStatement(table, columns, isCaseSensitive, options)
   }

sql/core/src/main/scala/org/apache/spark/sql/jdbc/JdbcDialects.scala

@@ -345,7 +345,10 @@ abstract class JdbcDialect extends Serializable with Logging {
       columns: Array[StructField],
       isCaseSensitive: Boolean,
       options: JDBCOptions): String =
-    throw new UnsupportedOperationException("upserts are not supported")
+    throw new SparkUnsupportedOperationException(
+      errorClass = "UNSUPPORTED_FEATURE.UPSERT",
+      messageParameters = Map(
+        "class" -> this.getClass.getSimpleName))
 
   /**
    * Override connection specific properties to run before a select is made.  This is in place to