hierarchical-data

问题 I have virtual folder structure saved in database and I want to get the breadcrumbs from the current folder to the root. The data can be unsorted (but better will be sorted) and I want the parent folders of the current folder only. The table definition is: DECLARE Folders TABLE ( FOL_PK INT IDENTITY(1,1) NOT NULL, FOL_Name VARCHAR(200) NOT NULL, FOL_FOL_FK INT NULL -- Foreign key to parent ) And this is my solution: DECLARE @FOL_PK INT = 5 -- Current folder PK DECLARE @breadcrumbs TABLE ( FOL

问题 I have two tables PLACE and ADRESS. PLACE includes places like parent-child hierarcy. ADRESS includes adresses with PLACE_ID column. These tables as shown below; PLACE ID PARENT_ID NAME CONTINENT 11 null USA America 22 11 New York America 33 22 Manhattan America 44 null Brasil America 55 44 Rio America 66 null France Europe 77 66 Paris Europe 88 66 Nice Europe MEMBER ID PLACE_ID NAME ADRESS 1 22 .. .. 2 77 .. .. 3 33 .. .. 4 22 .. .. 5 55 .. .. 6 55 .. .. 7 88 .. .. 8 88 .. .. 9 88 .. .. 10

问题 I have a table that contains tree-like data (hierarchic design). Here is a small sample: +----+----------+-----------+-------+----------+---------+ | ID | ParentID | Hierarchy | Order | FullPath | Project | +----+----------+-----------+-------+----------+---------+ | 1 | null | 1 | 1 | 1 | 1 | | 2 | null | 2 | 2 | 2 | 1 | | 3 | 1 | 1.1 | 1 | 1-3 | 1 | | 4 | 1 | 1.2 | 2 | 1-4 | 1 | | 5 | 4 | 1.2.1 | 1 | 1-4-5 | 1 | | 6 | 2 | 2.1 | 1 | 2-6 | 1 | | 7 | null | 3 | 1 | 1 | 2 | +----+----------+---

问题 I have a table that contains tree-like data (hierarchic design). Here is a small sample: +----+----------+-----------+-------+----------+---------+ | ID | ParentID | Hierarchy | Order | FullPath | Project | +----+----------+-----------+-------+----------+---------+ | 1 | null | 1 | 1 | 1 | 1 | | 2 | null | 2 | 2 | 2 | 1 | | 3 | 1 | 1.1 | 1 | 1-3 | 1 | | 4 | 1 | 1.2 | 2 | 1-4 | 1 | | 5 | 4 | 1.2.1 | 1 | 1-4-5 | 1 | | 6 | 2 | 2.1 | 1 | 2-6 | 1 | | 7 | null | 3 | 1 | 1 | 2 | +----+----------+---

问题 I'm seeking ideas to plot a tuple tree t = ((4,), (3, 5,), (2, 4, 6,), (1, 3, 5, 7,)) as the following image (assuming this binomial tree size can change). I'm trying to avoid dependencies on non-core packages (just sticking to pandas, numpy, matplotlib, scikit, and such). 回答1: I'm using this piece of code which gives a pretty good result: from matplotlib import pyplot as plt import numpy as np fig = plt.figure(figsize=[5, 5]) for i in range(3): x = [1, 0, 1] for j in range(i): x.append(0) x

问题 I'm seeking ideas to plot a tuple tree t = ((4,), (3, 5,), (2, 4, 6,), (1, 3, 5, 7,)) as the following image (assuming this binomial tree size can change). I'm trying to avoid dependencies on non-core packages (just sticking to pandas, numpy, matplotlib, scikit, and such). 回答1: I'm using this piece of code which gives a pretty good result: from matplotlib import pyplot as plt import numpy as np fig = plt.figure(figsize=[5, 5]) for i in range(3): x = [1, 0, 1] for j in range(i): x.append(0) x

问题 I have a folder table that joins to itself on an id , parent_id relationship: CREATE TABLE folders ( id int(10) unsigned NOT NULL AUTO_INCREMENT, title nvarchar(255) NOT NULL, parent_id int(10) unsigned DEFAULT NULL, PRIMARY KEY (id) ); INSERT INTO folders(id, title, parent_id) VALUES(1, 'root', null); INSERT INTO folders(id, title, parent_id) values(2, 'one', 1); INSERT INTO folders(id, title, parent_id) values(3, 'target', 2); INSERT INTO folders(id, title, parent_id) values(4, 'child one',

问题 I have a folder table that joins to itself on an id , parent_id relationship: CREATE TABLE folders ( id int(10) unsigned NOT NULL AUTO_INCREMENT, title nvarchar(255) NOT NULL, parent_id int(10) unsigned DEFAULT NULL, PRIMARY KEY (id) ); INSERT INTO folders(id, title, parent_id) VALUES(1, 'root', null); INSERT INTO folders(id, title, parent_id) values(2, 'one', 1); INSERT INTO folders(id, title, parent_id) values(3, 'target', 2); INSERT INTO folders(id, title, parent_id) values(4, 'child one',

来源： https://stackoverflow.com/questions/63575829/multilevel-mat-table-does-not-expand-to-another-level-after-first-sort

来源： https://stackoverflow.com/questions/63575829/multilevel-mat-table-does-not-expand-to-another-level-after-first-sort