Advanced Expressions – String concatenation

String Concatenation

To improve the user experience, various Concept Instances Rainbird gathers whilst completing a query can be combined  to create a string concatenation” . Using string concatenations allows Rainbird to return more detailed and conversational results. 

For example, if a query was being run to find out what language a user speaks, if using string concatenation, Rainbird could return a phrase such as “%USER speaks %LANGUAGE”; without string concatenation, Rainbird would just return the “%LANGUAGE” value:

Figure 1: Result not using string concatenation 

Figure 2: Result using string concatenation 

String concatenations can be built up with a variety of different elements, such as relationship subjects or objects (%S or %O), a specific value e.g %MAKE_OF_CAR, letters, words and/or symbols. 

It is important to combine every element in the string correctly, as well as to assign the expression to a variable (normally %O) for Rainbird to display the string concatenation:

  • Text has to be enclosed in apostrophes  ‘ ‘
  • Each String element is connected with a ‘+’ sign
  • Variables need to be in capital letters and spaces need to be replaced with an underscore e.g %EXAMPLE_CAR


Figure 3: Building a string concatenation

The concatenated string is then returned as a result:

Figure 4: Returned string concatenation

IMPORTANT: When using special symbols like an apostrophe in an expression,  you have to use an escaping character (backslash) before the symbol:

Escaping character Example

Figure 5: Creating a string concatenation with an escaping character

Figure 6: Returned string concatenation using an apostrophe

Click on the ‘Export.rbird’ button to download the ‘String Concatenation’ map used in this example. The knowledge map can then be imported into your Rainbird Studio.

The query that will demonstrate string concatenation in action is built on the relationship ‘infer’. The query outcome will demonstrate a string concatenation that uses an escaping character. Click below to export the .rbird file for the ‘what car do I have’ example.

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Version 1.01 – Last Update: 23/02/2021