Oracle PL-SQL 函数出现错误 PLS-00103：遇到以下符号之一时遇到符号 "SELECT"

Question

create or replace function noMembers(projNum integer) return integer IS
memCount integer;
Begin
    memCount := ( select count(*)
                from TABLE( select p.members from Projects p where p.projNo = projNum));
    return memCount;
End;
End;

当我尝试在 Oracle 中创建上述函数时 - SQL*另外，我得到了错误；

    LINE/COL ERROR
-------- -----------------------------------------------------------------
3/10     PLS-00103: Encountered the symbol "SELECT" when expecting one of
         the following:
         ( - + case mod new not null <an identifier>
         <a double-quoted delimited-identifier> <a bind variable>
         continue avg count current exists max min prior sql stddev
         sum variance execute forall merge time timestamp interval
         date <a string literal with character set specification>
         <a number> <a single-quoted SQL string> pipe
         <an alternatively-quoted string literal with character set
         specification>
         <an alternat
    LINE/COL ERROR
-------- -----------------------------------------------------------------

4/69     PLS-00103: Encountered the symbol ")" when expecting one of the
         following:
         , ; for <an identifier>
         <a double-quoted delimited-identifier> as group having
         intersect minus order start union where connect

似乎找不到函数声明有什么问题，我想return从函数分配给每个项目的成员数（成员计数）。

select count(*) from TABLE( select p.members from Projects p where p.projNo = 10 )

以上查询单独执行时效果很好。我还需要在函数中声明的“memCount”变量。
感谢任何帮助...

Answer 1

你不能这样分配查询结果；语法是：

select count(*)
into memCount 
from ...

db<>fiddle

语法is in the documentation

But is it possible to assign to the memCount variable by any chance ( I mean using ' := ' operator ) ?

Not directly from a query。您可以将整个集合查询到一个局部变量中，然后您可以分配它的计数：

create or replace function noMembers(projNum integer) return integer IS
    memCount integer;
    memColl projects.members%type;
Begin
    select p.members
    into memColl
    from Projects p where p.projNo = projNum;

    memCount := memColl.count;
    return memCount;
End;
/

或没有分配：

create or replace function noMembers(projNum integer) return integer IS
    memColl projects.members%type;
Begin
    select p.members
    into memColl
    from Projects p where p.projNo = projNum;

    return memColl.count;
End;
/

db<>fiddle

但除非您打算对集合做任何其他事情，否则这可能只是浪费精力和内存。

Oracle PL-SQL 函数出现错误 PLS-00103：遇到以下符号之一时遇到符号 "SELECT"

Oracle PL-SQL function getting error PLS-00103: Encountered the symbol "SELECT" when expecting one of the following

oracle

plsql

sqlplus