一个简单的存储过程,传递字符串变量作为参数,传递给过程中的in 子句;但似乎不起作用 。 代码如下
CREATE OR REPLACE PROCEDURE WSREVSECT_5 pSectNos varchar2, pRetCode OUT varchar2 ) AS nCount number; BEGIN SELECT count(fksrev) into nCount FROM SREVSECT WHERE sectno IN (pSectNos ) /* as in 'abc', 'xyz', '012' */; pRetCode:=to_char(ncount); End
it works -- the above is the same as
where sectno = pSectNos
though, not what you want. You want it to be:
where sectno in ( 'abc', 'xyz', '012' )
NOT:
where sectno in ( '''abc'', ''xyz'', ''012''' )
当直接使用select count(*) into .. from .. where sectno in (pSectNos) 的时候,相当于where sectno = pSectNos
which is effectively is (else you could never search on a string with commas and quotes and so on -- it is doing the only logical thing right now).
You can do this:
SQL> create or replace type myTableType as table of varchar2 (255); 2 /
Type created.
ops$tkyte@dev8i> create or replace function in_list( p_string in varchar2 ) return myTableType 2 as 3 l_string long default p_string ','; 4 l_data myTableType := myTableType(); 5 n number; 6 begin 7 loop 8 exit when l_string is null; 9 n := instr( l_string, ',' ); 10 l_data.extend; 11 l_data(l_data.count) := ltrim( rtrim( substr( l_string, 1, n-1 ) ) ); 12 l_string := substr( l_string, n+1 ); 13 end loop; 14 15 return l_data; 16 end; 17 /
Function created.
ops$tkyte@dev8i> select * 2 from THE ( select cast( in_list('abc, xyz, 012') as mytableType ) from dual ) a 3 /
COLUMN_VALUE ------------------------ abc xyz 012
ops$tkyte@dev8i> select * from all_users where username in 2 ( select * 3 from THE ( select cast( in_list('OPS$TKYTE, SYS, SYSTEM') as mytableType ) from dual ) ) 4 /
USERNAME USER_ID CREATED ------------------------------ ---------- --------- OPS$TKYTE 23761 02-MAY-00 SYS 0 20-APR-99 SYSTEM 5 20-APR-99
使用array如上绑定变量in-list的时候,要注重sql语句的执行计划;因为在有的版本下,cbo无法估计in-list virtual table的行数,产生不正确的执行计划。
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