我无法将存储过程从firebird转换为mysql。
以下是firebird的现有代码：

CREATE OR ALTER PROCEDURE GET_EOMONTH (
    selectmonth integer,
    selectyear integer)
returns (
    lastdate timestamp)
as
declare variable vmonth integer;
declare variable vyear integer;
begin
  VMONTH = selectmonth+1;
  VYEAR = selectyear;
  if (VMONTH=13) then
    BEGIN
      vmonth = 1;
      vyear =  selectyear + 1;
    END
  LASTDATE = CAST(VMONTH || '/1/' || VYEAR AS DATE) - 1;
  /* Procedure Text */
  suspend;
end^

然后我将上面的代码修改为：

CREATE PROCEDURE GET_EOMONTH (
    selectmonth integer,
    selectyear integer)
returns (
    lastdate timestamp)
as
declare variable vmonth integer;
declare variable vyear integer;
begin
  VMONTH = selectmonth+1;
  VYEAR = selectyear;
  if (VMONTH=13) then
    BEGIN
      vmonth = 1;
      vyear =  selectyear + 1;
    END
  LASTDATE = CAST(VMONTH || '/1/' || VYEAR AS DATE) - 1;
  /* Procedure Text */
  suspend;
end

从上面的代码中，我得到如下错误：
sql语法有错误；检查与mysql服务器版本对应的手册，以获得正确的语法，将near'（lastdate timestamp）用作第4行的declare variable vmonth integer'*/
--编辑
我又修改了一下：

DELIMITER $$
CREATE PROCEDURE GET_EOMONTH (
    IN selectmonth INT,
    IN selectyear INT,
     OUT LASTDATE VARCHAR(100))
BEGIN
DECLARE VMONTH INT;
DECLARE VYEAR INT;
  SET VMONTH = selectmonth+1;
  SET VYEAR = selectyear;
  IF (VMONTH=13) THEN
    BEGIN
      SET VMONTH = 1;
      SET VYEAR =  selectyear + 1;
    END;
   END IF;
  SET LASTDATE = CAST(VMONTH || '/1/' || VYEAR AS DATE) - 1;
  SELECT @LASTDATE;
END
END$$

但是，错误是：
sql错误（1064）：您的sql语法有错误；检查与mysql服务器版本相对应的手册，以获得第19行“end”附近使用的正确语法
请给我建议。
--编辑
现在我修改代码如下：

DELIMITER $$
CREATE PROCEDURE GET_EOMONTH (
    IN selectmonth INT,
    IN selectyear INT,
     OUT LASTDATE VARCHAR(100))
BEGIN
DECLARE VMONTH INT;
DECLARE VYEAR INT;
  SET VMONTH = selectmonth+1;
  SET VYEAR = selectyear;
  IF (VMONTH=13) THEN
    BEGIN
      SET VMONTH = 1;
      SET VYEAR =  selectyear + 1;
    END;
   END IF;
  SET LASTDATE = str_to_date(CONCAT(VYEAR, "-", VMONTH, "-1"), '%y/%m/%d') -1;
  SELECT @LASTDATE;
END$$
DELIMITER ;

而且很有效。