Instructions provided describe how to use Select by Attributes to find all the features for which Field1 is contained in Field2.
For example, select features for which Field1='Forest' and Field2='Pine Forest'. The syntax shown here is for shapefiles, but it can be adapted for any datasource which supports the SQL CONCAT, SUBSTRING and CHAR_LENGTH functions.
- Select 'Select by Attributes' from the Selection menu.
- Build an expression such as "Field2" LIKE '%[Field1 content]%'.
Using "Field1" returns the content of Field1 in SQL format which is surrounded by single quotes. The expression needs to extract the literal value of Field1 using SUBSTRING and CHAR_LENGTH:
- Concatenate the string with % to use it with the LIKE operator:
Note that CONCAT is used twice as it only concatenates two strings at a time.
- The final expression will be:
"Field2" LIKE CONCAT(CONCAT('%',SUBSTRING("Field1",1,CHAR_LENGTH("Field1"))),'%')