Firebird 3.0

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select rdb$get_context('SYSTEM', 'ENGINE_VERSION') as version
     , rdb$character_set_name
from rdb$database;

VERSION
RDB$CHARACTER_SET_NAME

3.0.5
UTF8

CREATE TABLE portfolio
(
  manager_name VARCHAR (25) NOT NULL,
  loan_amount      INTEGER      NOT NULL CHECK (loan_amount <= 100)
);

SELECT manager_name, SUM(loan_amount)
FROM portfolio
GROUP BY manager_name;

INSERT INTO portfolio VALUES ('man_1', 20);
1 rows affected

INSERT INTO portfolio VALUES ('man_1', 25);
1 rows affected

INSERT INTO portfolio VALUES ('man_1', 30);
1 rows affected

INSERT INTO portfolio VALUES ('man_2', 99);
1 rows affected

SELECT SUM(loan_amount) AS s FROM portfolio  GROUP BY manager_name;

S

75

99

ALTER TABLE portfolio
ADD CONSTRAINT no_huge_loans_ck_bis CHECK
(

  NOT EXISTS
  (
    SELECT SUM(loan_amount) AS s
    FROM portfolio 
    GROUP BY manager_name
    HAVING SUM(loan_amount) > 100
  )

);

--
-- fsasdfas
--
Dynamic SQL Error SQL error code = -104 Unexpected end of command - line 2, column 1 

INSERT INTO portfolio VALUES ('man_1', 500);
Operation violates CHECK constraint INTEG_3 on view or table PORTFOLIO At trigger 'CHECK_1' 

INSERT INTO portfolio VALUES ('man_1', 90);
1 rows affected

    SELECT SUM(loan_amount) AS s
    FROM portfolio 
    GROUP BY manager_name
    HAVING SUM(loan_amount) > 100;

S

165

INSERT INTO portfolio VALUES ('man_1', 1);
Operation violates CHECK constraint NO_HUGE_LOANS_CK_BIS on view or table PORTFOLIO At trigger 'CHECK_3' 

SELECT * FROM portfolio;

MANAGER_NAME
LOAN_AMOUNT

man_1
20

man_1
25

man_1
30

man_2
99

man_1
90

INSERT INTO portfolio VALUES ('man_1', 500);
Operation violates CHECK constraint INTEG_3 on view or table PORTFOLIO At trigger 'CHECK_1'