code: public boolean deleteByIds(String tableName, String primaryKey, Object... idValues) {
  		String[] pKeys = primaryKey.split(",");
  		if (pKeys.length != idValues.length)
  			throw new IllegalArgumentException("primary key number must equals id value number");
  		
  		String sql = config.dialect.forDbDeleteById(tableName, pKeys);
  		return update(sql, idValues) >= 1;
  	}
docs: Delete record by ids.
  <pre>
  Example:
  Db.use().deleteByIds("user", "user_id", 15);
  Db.use().deleteByIds("user_role", "user_id, role_id", 123, 456);
  </pre>
  @param tableName the table name of the table
  @param primaryKey the primary key of the table, composite primary key is separated by comma character: ","
  @param idValues the id value of the record, it can be composite id values
  @return true if delete succeed otherwise false