PoojaMoolya: Created page with "{|border=1 || '''Time''' || '''Narration''' |- || 00:01 ||Welcome to this tutorial on '''Table Joins''' and '''Spatial Joins''' in '''QGIS'''. |- || 00:08 || In this tutorial..."

2020-09-15T05:22:19Z

Created page with "{|border=1 || '''Time''' || '''Narration''' |- || 00:01 ||Welcome to this tutorial on '''Table Joins''' and '''Spatial Joins''' in '''QGIS'''. |- || 00:08 || In this tutorial..."

New page

{|border=1
|| '''Time'''
|| '''Narration'''
|-
|| 00:01
||Welcome to this tutorial on '''Table Joins''' and '''Spatial Joins''' in '''QGIS'''.

|-
|| 00:08
|| In this tutorial, we will learn to join the '''attribute tables''' of two '''data-sets''' having,

common field , and same '''spatial data'''

|-
|| 00:19
|| Here I am using

'''Ubuntu Linux''' OS version. 16.04

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|| 00:26
|| '''QGIS '''version 2.18

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|| 00:30
|| To follow this tutorial learner should be familiar with '''QGIS interface'''.

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|| 00:36
|| For the prerequisite '''QGIS '''tutorials, please visit this website.

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|| 00:42
|| Download the folder given in the '''Code files''' link, located below the player.

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||00:48
||Extract the contents of the downloaded zip file and save it in a folder.

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||00:54
|| I have already downloaded the '''Code files''', extracted and saved in a folder on the '''Desktop'''.

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|| 01:01
|| '''Double-click''' on the folder to open it.

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||01:04
||Locate '''Stations.shp '''file in the extracted folder.

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|| 01:09
|| The '''Stations.shp''' file shows locations of meteorological stations or air stations across India.

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||01:17
||Here we also have other files required to practice this tutorial.

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||01:23
|| Joining the '''attribute tables''' means, combining the '''attribute data''' between two '''data-sets'''.

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||01:30
|| There are two ways to join a table,

'''Table Join''' that is, joining '''tables''' having one or more common column '''data'''.

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||01:40
|| '''Spatial Join''' means joining '''tables''' having same '''spatial data'''.

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||01:46
||In this tutorial we will be demonstrating both the methods.

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||01:50
||For more information please visit this website.

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||01:54
||Open '''QGIS''' interface.

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||01:57
||First, we will join '''attribute tables''' having common field.

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||02:02
||Click on '''Add Vector Layer''' tool from the toolbar on the left-side.

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|| 02:07
|| '''Add Vector Layer''' dialog box opens.

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||02:10
||Click on '''Browse''' button next to '''Dataset''' field.

A dialog-box opens.

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||02:17
||Navigate to '''Stations.shp''' file from the '''Code files''' folder on the '''Desktop'''.

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||02:22
||Click on '''Open''' button.

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|| 02:25
|| In the '''Add vector layer''' dialog box, click on '''Open''' button.

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|| 02:30
|| The '''Stations.shp layer''' will be added in the '''Layers Panel'''.

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||02:35
||The corresponding map appears on the canvas.

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|| 02:39
|| This map shows point features, corresponding to meteorological stations located in different states in India.

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||02:47
||Let us open the '''attribute table''' for this '''layer'''.

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||02:51
||In the '''Layers Panel''', right-click on '''Stations.shp'''.

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|| 02:56
||From the context menu choose '''Open Attribute Table''' option.

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|| 03:01
|| '''Attribute table '''opens.

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||03:03
||Notice that '''data''' for only one attribute '''District ''' is available.

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|| 03:10
||Minimize the '''attribute table'''.

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||03:13
|| Now we will add another''' data-set''' which is a spreadsheet to the '''Layers Panel'''.

This data set is in '''CSV''' '''format'''.

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|| 03:23
|| Click on '''Layer''' menu on the menu bar.

Click on''' Add layer'''.

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||03:30
||From the sub-menu click on '''Add Delimited Text Layer''' option.

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|| 03:35
|| A dialog box opens.

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||03:38
||Click on '''Browse''' button located next to '''File Name '''field.

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||03:43
|| A dialog box opens.

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||03:46
||Navigate to '''Rainfall.csv''' file from the '''Code files''' folder on the '''Desktop'''.

Click on '''Open''' button.

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|| 03:54
|| In the '''Delimited Text File '''dialog box, select ''' CSV''' as''' File Format.'''

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|| 04:01
|| Select '''Geometry definition''' as '''No geometry.'''

Leave all other fields as such.

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|| 04:09
||Click on '''OK''' button.

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||04:12
||On '''QGIS''' canvas, '''Rainfall layer''' will be added in the '''Layers Panel'''.

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|| 04:18
|| Right-click on '''Rainfall layer'''.

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||04:21
||Click on the '''Open Attribute Table '''from the context menu.

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||04:26
|| '''Attribute table''' opens.

The '''attribute table''' has rainfall data from '''January''' to '''December''' for various districts.

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||04:37
||Maximize the '''Stations attribute table''' and compare both the '''tables'''.

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||04:43
||Please note, the '''District '''field is common in both '''Rainfall '''and '''Stations layers'''.

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|| 04:50
||Now we will add the '''attribute data''' from''' Rainfall layer''' to''' Stations layer'''.

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|| 04:56
|| In the '''Stations attribute table''' there is only one column named '''District'''.

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||05:02
||We will add the '''Rainfall data''' to the '''Stations attribute table'''.

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|| 05:07
||Close the '''attribute tables'''.

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|| 05:10
|| Select '''Stations layer''' in the '''Layers Panel'''.

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||05:14
||This '''layer''' will receive the new '''data''' from the '''Rainfall layer'''.

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|| 05:19
|| Right-click on '''Stations layer'''.

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||05:22
||Click on the '''Properties''' option from the context menu.

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|| 05:26
|| '''Layer Properties''' dialog box opens.

Click on '''Joins''' from the left panel.

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|| 05:33
|| In the new window, click on the '''plus '''sign, located on the bottom-left corner.

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||05:39
||'''Add vector join''' dialog box opens.

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|| 05:43
|| Here we have options to choose for '''Join layer''', '''Join field''' and '''Target field'''.

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||05:51
|| '''Join layer''' will be '''Rainfall layer''', from which '''data''' will be added to '''Stations attribute table'''.

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||05:59
||Here '''Rainfall layer''' is already selected.

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|| 06:03
|| '''Join field''' is the field or '''attribute''' in the '''Rainfall table''' to be joined.

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||06:10
||In the '''Join field''', select '''District''' from the drop-down.

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|| 06:15
|| '''Target field''' is the field to be joined in the '''Stations table'''.

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||06:20
||In the '''Target field''', '''District''' is already selected.

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||06:25
||This field is common to both the '''tables'''.

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|| 06:29
|| Check the check-box for '''Choose which fields are joined'''.

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||06:34
||The text-box below is now populated with all the columns and check-boxes.

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|| 06:41
|| Check the boxes for the columns '''January''' to '''Annual Average '''in the text box.

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|| 06:48
||Click on ''' OK''' button to close the '''Add vector join ''' dialog box.

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|| 06:53
|| In''' Layer Properties '''dialog box, information about layer and columns joined are indicated at the top.

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|| 07:02
||Click on '''Apply''' button, then '''OK '''button.

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|| 07:06
|| On the '''QGIS''' interface, as shown earlier open '''attribute table''' for '''Stations layer'''.

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|| 07:14
||Observe that this '''table''' shows '''Rainfall data''' for all the stations.

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||07:20
||Close '''attribute table'''.

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|| 07:23
|| Next, we will learn how to '''join attribute table''' of two '''data-sets''' by location.

|-
|| 07:30
||Let us add another '''layer''' to the '''Layers Panel'''.

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|| 07:34
|| For this click on '''Add Vector Layer''' tool.

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|| 07:38
|| In the '''Add Vector Layer''' dialog box, click on '''Browse''' button.

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|| 07:43
||Navigate to the '''Admin.shp''' from the '''Code files''' folder on the '''Desktop'''.

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|| 07:49
||Click on '''Open''' button.

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|| 07:51
|| Again click on '''Open''' button in the '''Add Vector Layer''' dialog box.

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|| 07:56
||'''Admin layer''' is now added to the '''Layers Panel'''.

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||08:00
||'''Admin layer''' map opens showing the administrative state boundaries of India.

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|| 08:07
|| Click the '''Admin layer''' in the '''Layers panel'''.

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|| 08:11
||Drag and bring it below '''Stations layer'''.

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|| 08:15
||Now we can view the point features located in different States.

|-
|| 08:20
||'''Open attribute table''' for '''Admin layer'''.

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|| 08:24
|| The '''attribute table''' shows information related to states.

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|| 08:29
||Minimize the '''Admin attribute table'''.

Again open the '''Stations attribute table'''.

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|| 08:36
||Now we will join the '''attributes''' by location for '''Stations layer''' and '''Admin layer'''.

|-
||08:43
||Close both the '''attribute tables'''.

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|| 08:47
|| Click on '''Vector''' menu.

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|| 08:48
||Scroll down the menu and click on '''Data Management Tools'''.

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|| 08:53
||From the sub-menu select '''Join attributes by location'''.

|-
||08:58
||'''Join attributes by location''' dialog box opens.
|-
||09:02
||Click on the drop-down for '''Target vector layer'''.

|-
|| 09:05
|| Here we need to specify the '''target vector layer''' for joining the '''attribute table'''.

|-
|| 09:12
||In our case we need to add new '''data''' to the '''Stations layer'''.

|-
|| 09:17
||Hence '''Stations layer''' is the '''Target Layer'''.

|-
|| 09:21
||So we will select''' Stations [EPSG: 4326]''' from the drop-down as '''target layer'''.

|-
|| 09:29
|| Click on the drop-down for '''Join vector layer'''.

|-
|| 09:33
||Here we have to select the '''layer''' which we want to join with the '''target layer'''.

|-
|| 09:40
||Select '''Admin [EPSG: 4326] '''from the drop-down.

|-
|| 09:45
|| Here we have several options for '''joining''' the '''attributes'''.

|-
|| 09:50
||We are interested to find the meteorological stations located in various states.

|-
|| 09:56
||So under '''Geometric predicate''', we will select '''within''' check-box.

Scroll down.

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|| 10:04
||Check the check-box for '''Open output file after running algorithm'''.

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|| 10:10
|| Leave the rest of the settings as default.

Click on the '''Run''' button.

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|| 10:17
|| Status bar at the bottom shows the progress of the processing algorithm.

Wait for the process to complete.

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|| 10:25
||On the canvas, a new '''layer''', '''Joined layer''' is added in the '''Layers Panel'''.

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||10:32
||Right-click on the '''Joined layer''' and open '''attribute table'''.

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|| 10:37
|| This '''table''' contains all the '''attributes''' from '''Admin layer''' for each point on the '''Stations layer.'''

|-
|| 10:45
||Every point feature has information about the state.

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|| 10:49
||Close the '''attribute table'''.

|-
||10:52
|| To save the project, click on '''Project '''menu from the menu bar.

Select '''Save As''' option.
|-
|| 11:01
||Give an appropriate name and select a convenient location.

|-
|| 11:06
||Click on '''Save''' button.

|-
|| 11:10
||Let us summarize.

|-
|| 11:12
|| In this tutorial we have learnt to join the '''attribute tables''' of two '''data-sets''' having,

common field, and same '''spatial data'''

|-
|| 11:22
|| As an assignment,

Join the '''rainfall data''' from June to December with the '''stations data'''.

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|| 11:30
|| Use '''Rainfall.csv''' and '''Stations.shp''' files given in the '''Code files''' folder.

|-
|| 11:37
||The completed assignment should look like this.

|-
|| 11:41
|| This video summarizes the Spoken Tutorial project.

Please download and watch it.
|-
|| 11:48
||The spoken tutorial project team conducts workshops and gives certificates.

For more information please write to us.

|-
|| 11:58
|| Please post your timed queries on this forum.
|-
|| 12:02
|| The Spoken Tutorial Project is funded by NMEICT, MHRD Government of India.

|-
|| 12:10
|| This tutorial is contributed by Ambadas Maske from College of Engineering Pune, Snehalatha Kaliappan and Himanshi Karwanje from IIT Bombay.

Thank you for joining.
|-
|}

QGIS/C3/Table-Joins-and-Spatial-Joins/English-timed - Revision history

PoojaMoolya: Created page with "{|border=1 || '''Time''' || '''Narration''' |- || 00:01 ||Welcome to this tutorial on '''Table Joins''' and '''Spatial Joins''' in '''QGIS'''. |- || 00:08 || In this tutorial..."