internal/database: change Exec to return rows affected

Change Exec so it return the number of rows affected by
the statement, rather than a sql.Result.

- We never use the other methods of sql.Result.

- It's annoying to get the number of affected rows from a sql.Result
  because of the error return value.

- Examination of github.com/lib/pq shows that there is no extra cost
  to calling sql.Result.RowsAffected after an Exec.

Change-Id: If16a15cbabf38755518732c4489109e0b01f2cd1
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/253079
Reviewed-by: Julie Qiu <julie@golang.org>

1 files changed, 1 insertions, 5 deletions

diff --git a/internal/postgres/versionstate.go b/internal/postgres/versionstate.go
index c7dcbfc0..69178f7f 100644
--- a/internal/postgres/versionstate.go
+++ b/internal/postgres/versionstate.go
@@ -79,7 +79,7 @@ func upsertModuleVersionState(ctx context.Context, db *database.DB, modulePath,
 		sqlErrorMsg = fetchErr.Error()
 	}
 
-	result, err := db.Exec(ctx, `
+	affected, err := db.Exec(ctx, `
 			INSERT INTO module_version_states AS mvs (
 				module_path,
 				version,
@@ -116,10 +116,6 @@ func upsertModuleVersionState(ctx context.Context, db *database.DB, modulePath,
 	if err != nil {
 		return err
 	}
-	affected, err := result.RowsAffected()
-	if err != nil {
-		return fmt.Errorf("result.RowsAffected(): %v", err)
-	}
 	if affected != 1 {
 		return fmt.Errorf("module version state update affected %d rows, expected exactly 1", affected)
 	}