Answers for "oracle drop if exists"

drop table if exists oracle

DECLARE
    existing_table number;
BEGIN
    SELECT count(*) into existing_table FROM ALL_TABLES
    WHERE TABLE_NAME = 'table_name' AND OWNER = 'owner';
    IF existing_table = 1 then
        EXECUTE IMMEDIATE 'DROP TABLE owner.table_name';
    END IF;
END;
/
CREATE TABLE owner.table_name (BDAY DATE, [...]);

oracle drop sequence if exists

DECLARE
    s_exist NUMBER(1);
BEGIN
    SELECT CASE WHEN exists(SELECT * FROM ALL_SEQUENCES 
                           WHERE SEQUENCE_NAME = 'seq_name') THEN 1
       	ELSE 0 
    END INTO s_exist FROM DUAL;
    IF s_exist = 1 THEN
        EXECUTE IMMEDIATE 'DROP SEQUENCE seq_name';
    END IF;
END;