The Concat field expression lets us concatenate the values of two or more stored fields into a single string. For instance, the following examples take Factbook Olympic Medal search results and concatenate the number of gold medals with the number of silver medals, into a new field called "Gold, Silver:". Note the use of a string constant in the FieldExpression array to force ", " into the concatenation.
Example:
QueryRequest request = new QueryRequest("*:*)");
request.addField(new Concat(new StoredField("gold_i"), new ConstantExpression(", "), new StoredField("silver_i")).as("Gold, Silver:"));
// ... (Perform Search)
REST Syntax:
CONCAT(FIELDEXPRESSION1, FIELDEXPRESSION2...) AS ALIAS
- FIELDEXPRESSION1 - First field to be concatenated.
- FIELDEXPRESSION2 - Second field to be concatenated.
- ALIAS - New field name for the resulting value.
Example:
&fields=CONCAT("gold_i",STRING(", "),"silver_i") as "Gold, Silver:"