Question

我不太确定我输入的内容是错误的。这是我从SQL代码收到的错误：

Msg 102，Level 15，State 1，Procedure GradeAverage，Line 22
'myCursor'附近的语法不正确。

功能：

CREATE FUNCTION GradeAverage 
   (@StudentID as varchar(20)) 
RETURNS int
AS
BEGIN
    DECLARE @Final int
    DECLARE @Grade int
    DECLARE @Total int= 0
    DECLARE @Count int = 0

    DECLARE myCursor CURSOR FOR
        SELECT FinalGrade
        FROM CourseEnrollment
        WHERE StudentId = @StudentID AND FinalGrade IS NOT NULL

    OPEN myCursor;

    FETCH NEXT FROM myCursor INTO @Grade

    WHILE @@FETCH_STATUS = 0
    BEGIN
        SET @Total = @Grade + @Total;
        SET @Count = @Count +1;

        FETCH NEXT FROM myCursor INTO @Grade
    END

    SET @Final = (@Total/@Count);

    CLOSE myCursor
    DEALLOCATE myCursor

    RETURNS @Final

Answer 1

第一个问题是RETURNS声明函数的返回类型，如RETURNS int中所示，但要实际指定返回值，您需要使用RETURN（否S）：

第二个问题是，函数定义中的每个BEGIN都必须与END匹配，包括围绕整个函数体的BEGIN / END。

最后，为了便于阅读，我建议您采用一些更标准的格式约定。它应该是这样的：

CREATE FUNCTION GradeAverage (@StudentID as varchar(20)) RETURNS int
AS
BEGIN
    DECLARE @Final int;
    DECLARE @Grade int;
    DECLARE @Total int= 0;
    DECLARE @Count int = 0;
    DECLARE myCursor CURSOR FOR
        SELECT FinalGrade
        FROM CourseEnrollment
        WHERE StudentId = @StudentID AND FinalGrade IS NOT NULL;
    OPEN myCursor;
    FETCH NEXT FROM myCursor INTO @Grade;
    WHILE @@FETCH_STATUS = 0
    BEGIN
        SET @Total = @Grade + @Total;
        SET @Count = @Count +1;
        FETCH NEXT FROM myCursor INTO @Grade;
    END
    SET @Final = (@Total/@Count);
    CLOSE myCursor;
    DEALLOCATE myCursor;
    RETURN @Final;
END

用光标函数，找不到错误

1 个答案: