Fix error drop column with BigQuery flexible column names (#12626) (#8982)

[upstream:102794ac7dd5df142dd4d362c034670b0a5604ff]

Signed-off-by: Modular Magician <magic-modules@google.com>

Author: modular-magician

.changelog/12626.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+bigquery: fixed DROP COLUMN error with bigquery flexible column names in `google_bigquery_table`
+```

google-beta/services/bigquery/resource_bigquery_table.go

@@ -2076,7 +2076,11 @@ func resourceBigQueryTableColumnDrop(config *transport_tpg.Config, userAgent str
 	}
 
 	if len(droppedColumns) > 0 {
-		droppedColumnsString := strings.Join(droppedColumns, ", DROP COLUMN ")
+		backquotedDroppedColumns := []string{}
+		for _, column := range droppedColumns {
+			backquotedDroppedColumns = append(backquotedDroppedColumns, fmt.Sprintf("`%s`", column))
+		}
+		droppedColumnsString := strings.Join(backquotedDroppedColumns, ", DROP COLUMN ")
 
 		dropColumnsDDL := fmt.Sprintf("ALTER TABLE `%s.%s.%s` DROP COLUMN %s", tableReference.project, tableReference.datasetID, tableReference.tableID, droppedColumnsString)
 		log.Printf("[INFO] Dropping columns in-place: %s", dropColumnsDDL)

google-beta/services/bigquery/resource_bigquery_table_test.go

@@ -415,9 +415,9 @@ func testAccBigLakeManagedTable(bucketName, connectionID, datasetID, tableID, sc
 			  file_format = "PARQUET"
 			  table_format = "ICEBERG"
 			}
-		
+
 			schema = jsonencode(%s)
-		
+
 			depends_on = [
 			  google_project_iam_member.test
 			]
@@ -2198,6 +2198,14 @@ resource "google_bigquery_table" "test" {
   {
     "name": "some_int",
     "type": "INTEGER"
+  },
+  {
+    "name": "reserved_word_for",
+    "type": "STRING"
+  },
+  {
+    "name": "flexible-column-name-dash",
+    "type": "STRING"
   }
 ]
 EOH
@@ -3106,7 +3114,7 @@ resource "google_bigquery_table" "test" {
   # Depends on Iceberg Table Files
   depends_on = [
 	google_storage_bucket_object.empty_data_folder,
-	google_storage_bucket_object.metadata, 
+	google_storage_bucket_object.metadata,
   ]
 }
 `, datasetID, bucketName, tableID)
@@ -3134,7 +3142,7 @@ resource "google_storage_bucket_object" "datafile" {
 
 # Upload Metadata file
 resource "google_storage_bucket_object" "manifest" {
-	name = "%s" 
+	name = "%s"
 	content = "gs://${google_storage_bucket.test.name}/${google_storage_bucket_object.datafile.name}"
 	bucket = google_storage_bucket.test.name
 }
@@ -4584,7 +4592,7 @@ resource "google_bigquery_table" "test" {
 ]
 EOF
 
-  external_catalog_table_options { 
+  external_catalog_table_options {
     parameters = {
       owner = "hashicorp-terraform"
     }
@@ -4639,7 +4647,7 @@ resource "google_bigquery_table" "test" {
 ]
 EOF
 
-  external_catalog_table_options { 
+  external_catalog_table_options {
     parameters = {
       owner = "hashicorp-terraform-updated"
     }