函数:

DELIMITER $$

CREATE
    FUNCTION `RandomDateTime`(sd DATETIME,ed DATETIME)
    RETURNS DATETIME
    BEGIN
	RETURN DATE_ADD(sd,INTERVAL FLOOR(1+RAND()*((ABS(UNIX_TIMESTAMP(ed)-UNIX_TIMESTAMP(sd)))-1)) SECOND);
    END$$

DELIMITER ;

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好看一点的

	DECLARE sub INT DEFAULT 0;
	DECLARE ret DATETIME;
	
	SET sub = ABS(UNIX_TIMESTAMP(ed)-UNIX_TIMESTAMP(sd));
	SET ret = DATE_ADD(sd,INTERVAL FLOOR(1+RAND()*(sub-1)) SECOND);
	

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测试:

SELECT RandomDateTime(DATE_FORMAT('2010-12-1 10:10:10','%Y-%m-%d %H:%i:%s'),DATE_FORMAT('2010-12-1 11:10:13','%Y-%m-%d %H:%i:%s')) AS t;

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