How do I get all the labels to show when they have exactly the same grid reference using QGIS?

Question

I map species records using QGIS 2.14.2. Many of the records have been submitted with exactly the same grid reference for different species. This can up to twenty records (labels). But QGIS will only show one of the records (labels) for that grid reference. I have checked "Show all labels". How do I get QGIS to show all the labels (records) for the one grid reference? Ideally this would be in a column or columns?

Answer 1

right click on the layer -> go to properties->go to labels -> tick 'label this layer with'-> click on the epsilon sign (expression dialog) and based on the example below type in your expression:

 'data1: '||$rownum || ' data2: '|| $id ||'\n' ||'data2: '||$currentfeature || ' data3: '|| $scale

where the $text is the name of a column

hope it helps.

Here is my update. Maybe you need to add some additional column or changes to your existing table like label_id (autoincrement) ordered by x or y coordinates. My expression is based on the number of 20 of maximum overlapping points, but in the condition you can add more. Please see my example: I have created a point layer with three attributes: is, species, info1.

Add label: right click on the layer -> go to properties->go to labels -> tick 'label this layer with'-> click on the epsilon sign (expression dialog) and based on the example below type in your expression: 'data1: ' || species || ' data2: '|| info1 || ' data3: '|| id

With this step you will see all the labels with their attributes, however if you have overlapping points you cannot see each layer especially if you have 20 overlapping. Here is my sample dataset (all the points are in the same position):

And here is the trick: right click on the layer -> go to properties->go to labels -> go to placement -> use offset from point -> change offset unit to millimeter -> and add an offset expression (highlighted on the picture below in the OFFSET X,Y line)-> clic on the expression button and edit.

Here is my sample expression, the rule is based on the species id:

CASE 
    WHEN right(species,2)= '01' THEN 
   '0,-2'
    WHEN right(species,2)= '02' THEN 
   '0,4'
    WHEN right(species,2)= '03' THEN 
   '0,-6'
    WHEN right(species,2)= '04' THEN 
   '0,8'
    WHEN right(species,2)= '05' THEN 
   '0,-10'
    WHEN right(species,2)= '06' THEN 
   '0,12'
    WHEN right(species,2)= '07' THEN 
   '0,-14'
    WHEN right(species,2)= '08' THEN 
   '0,16'
    WHEN right(species,2)= '09' THEN 
   '0,-18'
    WHEN right(species,2)= '10' THEN 
   '0,20'
    WHEN right(species,2)= '11' THEN 
   '0,-22'
    WHEN right(species,2)= '12' THEN 
   '0,24'
    WHEN right(species,2)= '13' THEN 
   '0,-26'
    WHEN right(species,2)= '14' THEN 
   '0,28'
    WHEN right(species,2)= '15' THEN 
   '0,-30'
    WHEN right(species,2)= '16' THEN 
   '0,32'
    WHEN right(species,2)= '17' THEN 
   '0,-34'
    WHEN right(species,2)= '18' THEN 
   '0,36'
    WHEN right(species,2)= '19' THEN 
   '0,-38'
    WHEN right(species,2)= '20' THEN 
   '0,40'

 ELSE 
    '0,-42'
END

It means you need to use the ending of your ID's (right formula) and each cases you need to set different offset. If you use ID's ending from 0-9 it my can happen you will have overlapping labels (if you have maximum 20 overlapping points), this is why it's necessary to add additional label_id column with cyclic label_id numbers. And the cyclic range should be the maximum number of the overlapping points.

End the result is: