跟新数据库，不存在则插入

mysql
如果a==1 那么更新，否则插入

INSERT INTO table (a,b,c) VALUES (1,2,3)  ON DUPLICATE KEY UPDATE b=b-1,c=c+1;

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oracle
如果表test.id = 1001 那么更新，否则插入

MERGE INTO TEST T1 USING(SELECT '1001' AS ID FROM dual) T2 ON ( T1.ID=T2.ID)WHEN MATCHED THEN  UPDATE SET T1.NAME = '3' ,T1.CODE = '3123' WHEN NOT MATCHED THEN  INSERT (ID,NAME,CODE) VALUES ('1001','32','1233');

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存储过程

SELECT COUNT(*) AS total INTO v_1 FROM table WHERE id = input_id;    IF v_1>0 THEN      UPDATE tabel      SET c1 = c1,        c2 = c2      WHERE id = input_id;    ELSE      INSERT      INTO table (c1,c2,id) VALUES        (          c1,          c2,          input_id        );    END IF;