Implement `add_tag`.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
index ed0965c..2739f42 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -81,6 +81,19 @@ impl TagBase {
             .collect();
         Ok(*id[0].as_ref().unwrap())
     }
+
+    /// Insert `tag` into the database, if it does not already exist.
+    fn add_tag(&self, tag: &str) -> Result<()> {
+        let exists = self
+            .conn
+            .prepare("SELECT * FROM tags WHERE name = ?")?
+            .exists(params![tag]);
+        if let Err(_) = exists {
+            self.conn
+                .execute("INSERT INTO tags (name) VALUES(?)", params![tag])?;
+        }
+        Ok(())
+    }
 }
 
 fn main() {