How to join two tables in Power BI on LIKE clause? Suppose we have two tables:
+------------------+ +--------+
| Messy_Name | | Tag |
+------------------+ +--------+
| red apple | | apple |
| apple very tasty | | banana |
| good apple green | +--------+
| yellow banana |
| banana split |
+------------------+
And we want to join them in PBI M or DAX (preferably both) imitating this SQL query:
select
a.Messy_Name
,b.Tag
from FactTable a
outer apply
(
select top 1
b.Tag
from TagList b
where a.Messy_Name like '%'+b.Tag+'%'
order by b.Tag
) b
So desired results would be:
+------------------+--------+
| Messy_Name | Tag |
+------------------+--------+
| red apple | apple |
| apple very tasty | apple |
| good apple green | apple |
| yellow banana | banana |
| banana split | banana |
+------------------+--------+
So the query is supposed to return the first Tag from the TagList table where Messy_Name contains the Tag. Eventually, this is one to one relationship.
To do this in Power Query, create a custom column with this formula
List.Max(
Table.SelectRows(Tags,
(T) => Text.Contains([Messy_Name], T[Tag]))[Tag])