QGIS – How to Insert Multi-Value Tags in Attribute Table Field with QGIS

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I am setting up a QGIS project using a Geopackage (or shapefile) concerning the areas named with some historical toponyms and writing a brief description of them.

In the attribute table I would like to include a field in the form of "tags" (such as Youtube videos or this forum), where I can insert more keywords referenced in a single field to assign a "kind" to the object and facilitate the management of data.

The question is that an element in my conceptual model can have more genres.

For example, an element can have keywords at the same time: "restaurant", "hotel", "garden".

In a field in the attribute table I am allowed to insert only one of these values.

How could I enter multiple values in a field as an alternative to a static text system "restaurant, hotel, garden"?

Best Answer

Use the "Value Relation" field widget to select multiple items from a list

1. Create a spreadsheet with two columns.

Call the first column "key." In this column, enter the values that you want saved in the attribute table. You can use your keywords, or you can assign a shorter key to each keyword. For example, I used numbers as my keys. The value "hotel" will be saved in the attribute table as 1. This allows you to store relatively long values in a more compact format. You could also use abbreviations, such as h for hotel, and g for garden. If you prefer, you can put the same value in each column.

Call the second column "value." In this column, put all of your keywords ("restaurant", "hotel", "garden" and so on).

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Save the spreadsheet in csv format.

2. Import the csv as an attribute-only table (ie without geometry).

3. Set up value relation widget

Open layer properties for the historical areas layer. Open the Attributes Form tab. Select the field (in my example the field is "categories"). For Widget Type, choose "value relation." For layer, select the table you added in step 2. (in my example the table is called "book2"). For key, select the key column. For value, select the value column.

When you create a new point, the data entry form will now give you a checklist.

The attribute table will store multiple values in a single field:

Related Solutions

[GIS] How to add a new column in attribute table with attribute with indexes of another max-min ordered attribute field

Here's a funny trick using a Spatialite query to get the values in descending order. If you do a count() and use a WHERE clause to get values >= the current value, then you'll actually be getting the order, so if I have a table "mypoints" with a column "value" and an empty column of "value_order" then:

SELECT value, (
SELECT count(*) FROM mypoints AS my 
WHERE my.value>=mypoints.value) AS orders
FROM mypoints 
ORDER BY value DESC;

gives a list of the values and their order. I can then update the "value_order" column like so:

UPDATE mypoints SET val_order = (
SELECT count(*) FROM mypoints AS my 
WHERE my.value>=mypoints.value
);

HTH

[GIS] Inserting text into field of attribute table in ArcGIS for Desktop

Select the rows that you want to add the text in using the Select by Attribute from the selection drop down, then using a query to get only those rows.

Open the attribute table then use the Field Calculator to add the required text in the rows, enable editing before you use the field calculator as any changes made outside of an editing session are permanent, Repeat this for all the attributes.

If you want to change the text in the attribute table, select the text in the attribute table and press control + f or go to the attribute table drop down and select find and replace. In there select the replace tab and use it to change the text that you want, be careful that you use it on Whole Field and not the whole attribute table.

Best Answer

Use the "Value Relation" field widget to select multiple items from a list

Related Solutions

[GIS] How to add a new column in attribute table with attribute with indexes of another max-min ordered attribute field

[GIS] Inserting text into field of attribute table in ArcGIS for Desktop

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