Postgres 12

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CREATE TABLE t1 (t1_id INT PRIMARY KEY);
CREATE TABLE t2 (t2_id INT PRIMARY KEY,
                 t1_id INT,
                 FOREIGN KEY (t1_id) REFERENCES t1 (t1_id));
WITH 
cte AS ( INSERT INTO t1 (t1_id) 
         VALUES (11)
         RETURNING t1_id)
INSERT INTO t2 (t2_id, t1_id)
SELECT 111, t1_id
FROM cte;
1 rows affected

SELECT * FROM t1;
SELECT * FROM t2;


t1_id


11




t2_id
t1_id


111
11