Draft pseudocode for database differencing

conn = new SQLConnection();

make_vcs_db_query = file_read(\Kickback\SCRIPT_ROOT . "/../meta/schema/kickback-kingdom-schema.mysql");

// Replace the schema name: `kickbackdb` -> `kickbackdb_vcs`
// (Ideally, we'd do this in a more syntax-aware way.
// Perhaps we could get mysqldump to parameterize the database name?
// Then we could parameterize the query instead of using fragile hacky regex stuff.)
make_vcs_db_query ~= s/\bkickbackdb\b/kickbackdb_vcs/g;

// Create the `kickbackdb_vcs` database.
conn.execute(make_vcs_db_query);

// Query that finds tables that exist in local database (kickbackdb) but not in VCS database (kickbackdb_vcs).
results = conn.execute("...");
diff.add_to_tables_removed(results);

// Query that finds tables that exist in VCS database (kickbackdb_vcs) but not in local database (kickbackdb).
results = conn.execute("...");
diff.add_to_tables_added(results);

// Query that finds tables that exist in BOTH databases.
table_list = conn.execute("...");
foreach( table in table_list )
{
  // Query that finds columns that exist in the local table, but not in the VCS table.
  results = conn.execute("...");
  diff.add_to_columns_removed(table, results);

  // Query that finds columns that exist in the VCS table, but not in the local table.
  results = conn.execute("...");
  diff.add_to_columns_added(table, results);

  // Query that finds keys that exist in the local table, but not in the VCS table.
  results = conn.execute("...");
  diff.add_to_keys_removed(table, results);

  // Query that finds keys that exist in the VCS table, but not in the local table.
  results = conn.execute("...");
  diff.add_to_keys_added(table, results);

  // ditto for any other table-level entities

  // Also you may want to diff for any data-level differences if the data
  // is something semantically significant in code.
  // (We should avoid semantically-signficant data as much as possible,
  // though things like badges in the current site ARE this kind of thing.)
  // So, like, adding a new badge type should probably appear in the diff.
}

// ditto for things like triggers, views, etc

// Query that deletes kickbackdb_vcs
conn.execute("...");

// Present the difference to the admin
display_diff(diff);