四、关于属性表(attribute table)的一些操作 1.打开属性表之后,再点击选中select features by area or single click,就可以通过直接选中选项表里的行来选中地图上相对应的区域,如图: 选中的这一行对应着黄色高亮的那个小区域(好像有点儿小) 同理,我们也可以通过按住ctrl的方式来选中多个连续或不连续的行,从而选中...
5. Selecting Features by Attribute A script to select features based on a specified attribute and value. ##Select_By_Attribute=name ##Input_layer=vector ##Field_name=field Input_layer ##Field_value=string layer = processing.getObject(Input_layer) layer.selectByExpression('"{}"=\'{}\''.fo...
Selecting Features by Attribute layer.selectByExpression('"attribute_name" = \'value\'') Buffering Features processing.run("native:buffer", {'INPUT': layer, 'DISTANCE': 10, 'OUTPUT': '/path/to/output.shp'}) Clipping One Layer with Another processing.run("native:clip", {'INPUT': layer_...
Before we proceed, let us de-select the features that were selected in the previous step. Go toEdit ‣ Select ‣ Deselect Features From All Layersor click theDeselect Features From All Layersbutton on theAttribute Toolbar. Activate theMapTipstool by going toView ‣ Map Tipsor clicking ...
about the field values, you can click theAll Uniquebutton to see what the attribute values are present in the dataset. For this exercise, we are looking to find all features that have a population greater than 1 million. So complete the expression as below and clickSelect Featuresand then...
SELECT * FROM jilin_dist left outer join prec on jilin_dist.NAME = prec.city; 该语句可以通过jilin_dist图层的“NAME”字段和prec图层的“city”字段将prec图层的属性连接到jilin_dist图层中。 单击“Add”按钮即可在图层列表中看到该虚拟图层。打开virtual_layer图层的Attribute Table可以看到连接后的数据表,如...
矢量数据的属性表通过图层右键菜单的“Open Attribute Table”选项打开。QGIS属性表有两种表现形式:表格视图(Table View)和表单视图(Form View),如图3-7所示。 图3-7 矢量数据图层的属性表 表格视图以数据为中心,以数据表的形式展示所有要素的属性。每个要素(Feature)都对应表格的一行(Row),也称为一个记录(Record...
Map Tools: Selecting all features by attribute value from Identify Results panel User Interface: Coordinate ordering according to CRS User Interface: Select features from expression based symbols User Interface: Copy preview expression value to clipboard User Interface: Option to synchronize statistics pane...
使用查询和选择来回答一系列关于数据集的问题。 一、数据集中总共包含多少所学院和大学? 右键点选CollegesUniversities图层,点击Open Attribute Table菜单,即可在属性表界面找到Features总数为7126. 二、首先寻找科罗拉多州总入学人数最高的大学。大学的宿舍可以容纳这所学校入学的学生百分比是多少吗?将答案四舍五入到最接近...
supported by OGR .br *Raster support for a large number of formats .br *Identify features .br *Display attribute tables .br *Select features .br *GRASS Digitizing .br *Feature labeling .br .SHOPTIONS .TP .B\--snapshotfilename Create a snapshot image from the specified layers and save ...