Feature functions
You can use feature functions in sort expressions. Most feature functions can be used only in fine sort expressions. You can combine various syntax and statements to perform complex sorts.
The fields that you reference in the parameters of feature functions must be configured as index fields or attribute fields based on the description of each function.
field_length: returns the number of terms in a field
1. Syntax
field_length(field_name)
2. Parameters
field_name: the name of the field for which you want to collect statistics. The field must be of the TEXT or SHORT_TEXT type. The analyzer can be the general analyzer for Chinese, a custom analyzer, the single character analyzer for Chinese, an analyzer for English, or the fuzzy analyzer.
3. Return value
int
4. Scenarios
Scenario 1
Specify different term weights based on the number of terms in a field.
if (field_length(title) > 200, 0.3, 0.7)5. Usage notes
The field that you reference in the parameter of this feature function must be configured as an index field.
You can use this feature function in fine sort expressions.