在 SYS_REFCURSOR 中执行动态 sql 语句

Question

是否可以在 plsql 中执行一条动态 sql 并将结果返回到 sys_refcursor 中？到目前为止，我已经粘贴了我的尝试，但是没有接缝正在工作，这是我通过我的 java 应用程序遇到的错误

ORA-01006: 绑定变量没有 存在 ORA-06512: 在 “LIVEFIS.ERC_REPORT_PK”，第 116 行 ORA-06512: 在第 1 行

但这可能是java误解的东西，一切都很好编译所以我不确定。

 procedure all_carers_param_dy (pPostcode in carer.postcode%type, pAge Number
                                ,pReport out SYS_REFCURSOR) is
  begin
    declare
      lsql  varchar2(500) :='SELECT c.id FROM carer c, cared_for cf,carer_cared_for ccf '
          ||' where c.id = ccf.carer_id (+)'
          ||' AND cf.id (+) = ccf.cared_for_id';

    begin

     if pPostcode is not null and pAge <= 0 then
        lsql := lsql||' AND c.postcode like ''%''|| upper(pPostcode)||''%''';
      elsif pPostcode is null and pAge > 0 then 
         lsql := lsql||' AND ROUND((MONTHS_BETWEEN(sysdate,c.date_of_birth)/12)) = pAge';
      elsif pPostcode is not null and pAge > 0 then
         lsql := lsql ||' AND ROUND((MONTHS_BETWEEN(sysdate,c.date_of_birth)/12)) = pAge'
                      ||' AND c.postcode like ''%''|| upper(pPostcode)||''%''';
      end if;


        execute immediate lsql
        into pReport;


    end;
  end;

我是 plsql 的新手，甚至是动态 sql 的新手，所以任何帮助/建议都将不胜感激。

再次感谢

乔恩

Answer 1

您必须绑定参数pAge 和pPostcode。在动态 SQL 中，您可以在它们前面加上一个冒号 (:)。如果您使用EXECUTE IMMEDIATE 或OPEN ... FOR，您将通过位置绑定您的参数，这就是我在示例中将它们重命名为:P1 和:P2 的原因：

DECLARE
   lsql VARCHAR2(500) := 'SELECT c.id 
                            FROM carer c, cared_for cf, carer_cared_for ccf 
                           WHERE c.id = ccf.carer_id (+)
                             AND cf.id (+) = ccf.cared_for_id';
BEGIN
   IF pPostcode IS NULL THEN
      lsql := lsql || ' AND :P1 IS NULL';
   ELSE
      lsql := lsql || ' AND c.postcode like ''%''|| upper(:P1)||''%''';
   IF pPostcode pAge > 0 THEN
      lsql := lsql || ' AND :P2 = ROUND((MONTHS_BETWEEN(sysdate,
                                                        c.date_of_birth)/12))';
   ELSE
      lsql := lsql || ' AND nvl(:P2, -1) <= 0';
   END IF;
   OPEN pReport FOR lsql USING pPostcode, pAge;
END;

注意：绑定变量的数量和位置必须在编译时知道，这就是为什么我经常使用上面的构造（即使不使用参数也要添加到它的位置） .向查询添加重言式（如AND :P1 IS NULL）不会影响其解释计划。

Answer 2

您不能通过使用立即执行来分配引用。

您必须将 SQL 构建成一个字符串，然后使用 open。

sql_str := 'SELECT * FROM...';
open pReport for sql_str;

Answer 3

使用 OPEN FOR 语法和绑定变量。

procedure all_carers_param_dy (pPostcode in carer.postcode%type, pAge Number
                            ,pReport out SYS_REFCURSOR) 
is
  lsql  varchar2(500) :='SELECT c.id FROM carer c, cared_for cf,carer_cared_for ccf '
      ||' where c.id = ccf.carer_id (+)'
      ||' AND cf.id (+) = ccf.cared_for_id';

begin

 if pPostcode is not null and pAge <= 0 then
    lsql := lsql||' AND c.postcode like upper(''%''||:1||''%'')';
    open pReport for lsql using pPostcode;
  elsif pPostcode is null and pAge > 0 then 
     lsql := lsql||' AND ROUND((MONTHS_BETWEEN(sysdate,c.date_of_birth)/12)) = :1';
    open pReport for lsql using pAge;
  elsif pPostcode is not null and pAge > 0 then
     lsql := lsql ||' AND ROUND((MONTHS_BETWEEN(sysdate,c.date_of_birth)/12)) = :1'
                  ||' AND c.postcode like upper(''%''||:2||''%'')';
    open pReport for lsql using pAge, pPostcode;
  end if;

end all_carers_param_dy;
/

动态 SQL 很难，很难理解，也很难做到正确。棘手的领域之一是处理重复。将 bolierplate 的重复部分声明为常量是一个好主意。另外，请注意，我们可以将大字符串拆分为多行，而不必将它们与'||' 连接起来。这减少了维护开销。

create or replace procedure all_carers_param_dy 
    (pPostcode in carer.postcode%type
      , pAge Number 
      , pReport out SYS_REFCURSOR)  
is 
  lsql varchar2(500) ;

  root_string constant varchar2(500) :='SELECT c.id FROM carer c
                                , cared_for cf,carer_cared_for ccf   
                      where c.id = ccf.carer_id (+)  
                      and cf.id (+) = ccf.cared_for_id'; 
  pc_string constant varchar2(256) := 
      ' AND c.postcode like upper(''%''||:pc||''%'')';
  age_string constant varchar2(256) := 
      ' AND ROUND((MONTHS_BETWEEN(sysdate,c.date_of_birth)/12)) = :age';
begin 

 if pPostcode is not null and pAge <= 0 then 
    lsql := root_string || pc_string; 
    open pReport for lsql using pPostcode; 

  elsif pPostcode is null and pAge > 0 then  
     lsql := root_string || age_string; 
    open pReport for lsql using pAge; 

  elsif pPostcode is not null and pAge > 0 then 
     lsql := root_string || age_string 
                         || pc_string; 
    open pReport for lsql using pAge, pPostcode; 

  end if; 
end all_carers_param_dy; 
/ 

Answer 4

是的，这是可能的。这样做：

v_sql := 'BEGIN OPEN :1 FOR :2 USING ';
v_bindvars := pPostcode ||', '||pAge; --this part you can create dynamically base on your if's
v_sql := v_sql||v_bindvars||' ; END;';
v_select := 'select yourdata from dual where 1 = :bind_first_var and 2 = :bind_second_var';

execute immediate v_sql using pReport, v_select;