fix: filter migrations by file number instead of list index

src/db/migrate.py

@@ -1,10 +1,17 @@
 import os
+import re
+
 import bcrypt
 import importlib
 
 from pyinfraboxutils import get_logger, get_env
 from pyinfraboxutils.db import connect_db
 
+
+# Matches C-style block comments (/* ... */), across multiple lines.
+# Non-greedy so consecutive `/* a */ x /* b */` blocks are matched independently.
+_BLOCK_COMMENT_RE = re.compile(r'/\*.*?\*/', re.DOTALL)
+
 logger = get_logger("migrate")
 
 def get_files(current_schema_version):
@@ -14,10 +21,40 @@ def get_files(current_schema_version):
     files = [f for f in os.listdir(migration_path) if os.path.isfile(os.path.join(migration_path, f)) and f.startswith('0')]
 
     files.sort(key=lambda f: int(f[:5]))
-    files = files[current_schema_version:]
+    files = [f for f in files if int(f[:5]) > current_schema_version]
 
     return [(os.path.join(migration_path, f), int(f[:5])) for f in files]
 
+def _has_executable_sql(sql):
+    """Return True iff `sql` contains at least one non-comment, non-blank line.
+
+    `str.strip()` only removes leading/trailing whitespace; SQL comments are
+    kept.  Passing a comment-only string to `cur.execute()` raises
+    `psycopg2.ProgrammingError: can't execute an empty query`, which breaks
+    migration runs whenever a placeholder file (e.g. an intentionally empty
+    migration to close a numbering gap) is applied.  This helper detects such
+    files so the caller can skip the execute call.
+
+    Recognised as "no SQL":
+      - completely empty / whitespace-only files
+      - only `-- ...` line comments
+      - only `/* ... */` block comments (even across lines)
+      - any combination of the above
+
+    Lightweight heuristic — does not tokenise SQL, so quoted strings that
+    happen to contain `--` or `/* */` are still treated as executable
+    (which is fine, they contain real statements).
+    """
+    # Strip C-style block comments first so any `/* ... */`-only content is
+    # collapsed away before the per-line `--` check.
+    sql_no_block = _BLOCK_COMMENT_RE.sub('', sql)
+    for line in sql_no_block.splitlines():
+        stripped = line.strip()
+        if stripped and not stripped.startswith('--'):
+            return True
+    return False
+
+
 def apply_migration(conn, migration):
     filename = migration[0]
     logger.info("Starting to apply migration %s", filename)
@@ -27,8 +64,13 @@ def apply_migration(conn, migration):
             sql = sql_file.read().strip()
 
             cur = conn.cursor()
-            if sql:
+            if _has_executable_sql(sql):
                 cur.execute(sql)
+            else:
+                logger.info(
+                    "Skipping execute for %s (no non-comment SQL statements)",
+                    filename,
+                )
 
             cur.close()
     elif filename.endswith('.py'):