# TSQLStructure- This is hierarchical structure, which is created when data is written by TBufferSQL2. It contains data all structural information such: version of written class, data member types of that class, value for each data member and so on. Such structure in some sense similar to XML node and subnodes structure Once it created, it converted to SQL statements, which are submitted to database server. ```cpp class TSQLColumnData : public TObject class TSQLTableData : public TObject ``` ## class **TSQLColumnData** ```cpp protected: TString fName; ///