tree_grid

A tree. Type is tree_grid. The shape matches data_grid: Component, Toolbar, and Grid. Lowercase keys in Option.Grid are dxTreeList options. The parent field is usually parentIdExpr together with keyExpr.

Component uses the same LoadSql, InsertRowSql, UpdateRowSql, and DeleteRowSql. Button names are the same set as the grid.

Where it differs from a grid

The query result has to include roots. Leaves alone leave the tree without a top. Keep a column that identifies the root (for example root, or an equivalent root id), plus id and parent_id (or path). When a parent is missing from the result, the engine inserts a root stub.

Group rows use Component.Folder:

Key	Meaning
Field	Which field marks this row as a group row
Expr	Or an expression that decides it
TrueValue / FalseValue	Values of Field that mean group row and normal row
OnlyEditableFields	Columns that stay editable on a group row
ReadOnlyFields	Columns that are read-only on a group row

AddFolder, ExpandAll, CollapseAll, MoveUp, and MoveDown on the toolbar are for the tree. MoveUp and MoveDown use Component.SeqField.