added login api

database/db.go

@@ -73,3 +73,32 @@ func InsertUser(db *sql.DB, username string, passwordHash string) (string, error
 	}
 	return userId, err
 }
+
+func GetPasswordHash(db *sql.DB, username string) (string, error) {
+	query := `
+    SELECT password_hash FROM Accounts 
+    WHERE LOWER(username) = LOWER($1);
+  `
+
+	var passwordHash string
+	err := db.QueryRow(query, username).Scan(&passwordHash)
+	if err != nil {
+		return "", fmt.Errorf("error getting password: %v", err)
+	}
+
+	return passwordHash, err
+}
+
+func GetUserId(db *sql.DB, username string) (string, error) {
+	query := `
+    SELECT user_id, username AS dbUsername FROM Accounts
+    WHERE LOWER(username) = $1;
+  `
+
+	var dbUsername string
+	err := db.QueryRow(query, username).Scan(&dbUsername, &dbUsername)
+	if err != nil {
+		return "", fmt.Errorf("error getting user id: %v", err)
+	}
+	return dbUsername, err
+}