code: protected function findColumns($table)
      {
          $sql = 'PRAGMA table_info(' . $this->quoteSimpleTableName($table->name) . ')';
          $columns = $this->db->createCommand($sql)->queryAll();
          if (empty($columns)) {
              return false;
          }
  
          foreach ($columns as $info) {
              $column = $this->loadColumnSchema($info);
              $table->columns[$column->name] = $column;
              if ($column->isPrimaryKey) {
                  $table->primaryKey[] = $column->name;
              }
          }
          if (count($table->primaryKey) === 1 && !strncasecmp($table->columns[$table->primaryKey[0]]->dbType, 'int', 3)) {
              $table->sequenceName = '';
              $table->columns[$table->primaryKey[0]]->autoIncrement = true;
          }
  
          return true;
      }
docs: Collects the table column metadata.
  @param TableSchema $table the table metadata
  @return bool whether the table exists in the database