Fix backfill on tables with case sensitive names (#831)

Ensure that the table name is correctly quoted when retrieving table
rows counts as part of the backfill operation.

Fixes #826

Author: andrew-farries

pkg/backfill/backfill.go

@@ -122,7 +122,7 @@ func getRowCount(ctx context.Context, conn db.DB, tableName string) (int64, erro
 	}
 
 	// If the estimate is zero, fall back to full count
-	rows, err = conn.QueryContext(ctx, fmt.Sprintf(`SELECT count(*) from %s`, tableName))
+	rows, err = conn.QueryContext(ctx, fmt.Sprintf(`SELECT count(*) from %s`, pq.QuoteIdentifier(tableName)))
 	if err != nil {
 		return 0, fmt.Errorf("getting row count for %q: %w", tableName, err)
 	}

pkg/migrations/op_change_type_test.go

@@ -649,6 +649,54 @@ func TestChangeColumnType(t *testing.T) {
 				ColumnMustHaveComment(t, db, schema, "users", "username", "the name of the user")
 			},
 		},
+		{
+			name: "can change the type of a column on a table with a case-sensitive name",
+			migrations: []migrations.Migration{
+				{
+					Name: "01_add_table",
+					Operations: migrations.Operations{
+						&migrations.OpCreateTable{
+							Name: "Users",
+							Columns: []migrations.Column{
+								{
+									Name: "id",
+									Type: "serial",
+									Pk:   true,
+								},
+								{
+									Name: "name",
+									Type: "varchar(255)",
+								},
+							},
+						},
+					},
+				},
+				{
+					Name: "02_change_type",
+					Operations: migrations.Operations{
+						&migrations.OpAlterColumn{
+							Table:  "Users",
+							Column: "name",
+							Type:   ptr("text"),
+							Up:     "name",
+							Down:   "name",
+						},
+					},
+				},
+			},
+			afterStart: func(t *testing.T, db *sql.DB, schema string) {
+				// The new column has the expected type
+				ColumnMustHaveType(t, db, schema, "Users", migrations.TemporaryName("name"), "text")
+			},
+			afterRollback: func(t *testing.T, db *sql.DB, schema string) {
+				// The table has been cleaned up
+				TableMustBeCleanedUp(t, db, schema, "Users", "name")
+			},
+			afterComplete: func(t *testing.T, db *sql.DB, schema string) {
+				// The new column has the expected type
+				ColumnMustHaveType(t, db, schema, "Users", "name", "text")
+			},
+		},
 	})
 }
 

pkg/migrations/op_common_test.go

@@ -575,7 +575,7 @@ func triggerExists(t *testing.T, db *sql.DB, schema, table, trigger string) bool
       WHERE tgrelid = $1::regclass
       AND tgname = $2
     )`,
-		fmt.Sprintf("%s.%s", schema, table), trigger).Scan(&exists)
+		fmt.Sprintf("%s.%s", pq.QuoteIdentifier(schema), pq.QuoteIdentifier(table)), trigger).Scan(&exists)
 	if err != nil {
 		t.Fatal(err)
 	}