drop table if exists t1;
select CASE "b" when "a" then 1 when "b" then 2 END;
CASE "b" when "a" then 1 when "b" then 2 END
2
select CASE "c" when "a" then 1 when "b" then 2 END;
CASE "c" when "a" then 1 when "b" then 2 END
NULL
select CASE "c" when "a" then 1 when "b" then 2 ELSE 3 END;
CASE "c" when "a" then 1 when "b" then 2 ELSE 3 END
3
select CASE BINARY "b" when "a" then 1 when "B" then 2 WHEN "b" then "ok" END;
CASE BINARY "b" when "a" then 1 when "B" then 2 WHEN "b" then "ok" END
ok
select CASE "b" when "a" then 1 when binary "B" then 2 WHEN "b" then "ok" END;
CASE "b" when "a" then 1 when binary "B" then 2 WHEN "b" then "ok" END
ok
select CASE concat("a","b") when concat("ab","") then "a" when "b" then "b" end;
CASE concat("a","b") when concat("ab","") then "a" when "b" then "b" end
a
select CASE when 1=0 then "true" else "false" END;
CASE when 1=0 then "true" else "false" END
false
select CASE 1 when 1 then "one" WHEN 2 then "two" ELSE "more" END;
CASE 1 when 1 then "one" WHEN 2 then "two" ELSE "more" END
one
select CASE 2.0 when 1 then "one" WHEN 2.0 then "two" ELSE "more" END;
CASE 2.0 when 1 then "one" WHEN 2.0 then "two" ELSE "more" END
two
select (CASE "two" when "one" then "1" WHEN "two" then "2" END) | 0;
(CASE "two" when "one" then "1" WHEN "two" then "2" END) | 0
2
select (CASE "two" when "one" then 1.00 WHEN "two" then 2.00 END) +0.0;
(CASE "two" when "one" then 1.00 WHEN "two" then 2.00 END) +0.0
2.00
select case 1/0 when "a" then "true" else "false" END;
case 1/0 when "a" then "true" else "false" END
false
select case 1/0 when "a" then "true" END;
case 1/0 when "a" then "true" END
NULL
select (case 1/0 when "a" then "true" END) | 0;
(case 1/0 when "a" then "true" END) | 0
NULL
select (case 1/0 when "a" then "true" END) + 0.0;
(case 1/0 when "a" then "true" END) + 0.0
NULL
select case when 1>0 then "TRUE" else "FALSE" END;
case when 1>0 then "TRUE" else "FALSE" END
TRUE
select case when 1<0 then "TRUE" else "FALSE" END;
case when 1<0 then "TRUE" else "FALSE" END
FALSE
create table t1 (a int);
insert into t1 values(1),(2),(3),(4);
select case a when 1 then 2 when 2 then 3 else 0 end as fcase, count(*) from t1 group by fcase;
fcase	count(*)
0	2
2	1
3	1
select case a when 1 then "one" when 2 then "two" else "nothing" end as fcase, count(*) from t1 group by fcase;
fcase	count(*)
nothing	2
one	1
two	1
drop table t1;