Extract out table-exists?

1 files changed, 13 insertions, 7 deletions

diff --git a/nar-herder/database.scm b/nar-herder/database.scm
index 64655df..d945786 100644
--- a/nar-herder/database.scm
+++ b/nar-herder/database.scm
@@ -126,22 +126,28 @@ CREATE TABLE recent_changes (
 
   (sqlite-exec db schema))
 
-(define (update-schema db)
+(define (table-exists? db name)
   (let ((statement
          (sqlite-prepare
           db
           "
-SELECT name FROM sqlite_master WHERE type = 'table' AND name = :name")))
+SELECT 1 FROM sqlite_master WHERE type = 'table' AND name = :name")))
 
     (sqlite-bind-arguments
      statement
-     #:name "narinfos")
+     #:name name)
+
+    (let ((result
+           (match (sqlite-step statement)
+             (#f #f)
+             (#(1) #t))))
+      (sqlite-finalize statement)
 
-    (match (sqlite-step statement)
-      (#f (perform-initial-database-setup db))
-      (_ #f))
+      result)))
 
-    (sqlite-finalize statement))
+(define (update-schema db)
+  (unless (table-exists? db "narinfos")
+    (perform-initial-database-setup db))
 
   (sqlite-exec
    db