Postgres 12

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create table test(
    column1 int, 
    column2 int, 
    column3 text generated always as (
        case 
            when column1 <= -7000 then 'small'
            when column1 <= 15    then 'nohello'
            else 'nodata'
        end
    ) stored
);
INSERT INTO test(column1, column2) VALUES(-8020,15),(-200,1),(23,115)
3 rows affected

select * from test;


column1
column2
column3


-8020
15
small

-200
1
nohello

23
115
nodata