如何使用PL/SQL中的select语句为SQL * Plus变量赋值？

Question

如何使用select语句为变量赋值并在SQL * Plus脚本中使用它，如下所示？

VARIABLE FullCatCode VARCHAR2(7) 

exec :FullCatCode := (SELECT CatCode from draw_catcodes where series = 123 and base = 158); 

SELECT :FullCatCode || '-' || Other stuff... from table_name... 

编辑：@AlexPoole，对不准确的问题陈述。我从280K记录数据集中提取50列数据。我正在根据辅助表（draw_catcodes）的子字符串为每个记录分配nextval序列。我正在SQL * Plus中运行SELECT语句，后台处理为CSV文件。该SQL现在看起来是这样（下面的测试你的第二个建议）：

COLUMN CatCode NEW_VALUE FullCatCode; 

SELECT 
(CASE d.image WHEN 0 THEN 'NoImage.pdf' 
ELSE lower(d.prefix || lpad(d.series,3,0) || lpad(d.base,3,0) || lpad(d.suffix,2,0) || lpad(d.rev,2,0) || '.pdf') END) as "Filename", 
(SELECT EngDiscipline from draw_catcodes c where d.series = c.series and d.base = c.base) as "EngDiscipline", 

(SELECT CatCode from draw_catcodes c where d.series = c.series and d.base = c.base), 

SELECT &FullCatCode || '-' || 
lpad((CASE substr(&FullCatCode,0,3) 
WHEN 'AEG' THEN (SELECT AEG_seq.NEXTVAL FROM DUAL) 
WHEN 'ARY' THEN (SELECT ARY_seq.NEXTVAL FROM DUAL) 
WHEN 'BBR' THEN (SELECT BBR_seq.NEXTVAL FROM DUAL) 
ELSE 0 
END),6,0) as "ItemID", 
upper(d.prefix || '-' || lpad(d.series,3,0) || '-' || lpad(d.base,3,0) || '-' || lpad(d.suffix,2,0)) as "LegacyID", 
... 
from tablename where ... 

我开始与存储的功能是“Upserted”序列表（不能从功能进行DML），尝试了存储过程有一个OUT变量（无法从SQL SELECT中调用过程），现在在CASE语句中尝试序列（无法弄清楚如何使用上述变量）......任何建议都将非常感谢！

编辑：@AlexPoole，由于变量不会在这种情况下工作，我只是直接选择我的价值，然后使用CASE语句来指定正确的序列。语法是不正确的，虽然，因为我得到一个ORA-00933：

SELECT ((SELECT CatCode from draw_catcodes c where d.series = c.series and d.base = c.base) || '-' || 
lpad((CASE substr((SELECT CatCode from draw_catcodes c where d.series = c.series and d.base = c.base),0,3) 
WHEN 'AEG' THEN AEG_seq.NEXTVAL 
WHEN 'ARY' THEN ARY_seq.NEXTVAL 
WHEN 'BBR' THEN BBR_seq.NEXTVAL 
... 
WHEN 'SPR' THEN SPR_seq.NEXTVAL 
WHEN 'SRL' THEN SRL_seq.NEXTVAL 
ELSE 0 
END),6,0)) as "ItemID" FROM DUAL, 
upper(d.prefix || '-' || lpad(d.series,3,0) || '-' || lpad(d.base,3,0) || '-' || lpad(d.suffix,2,0)) as "LegacyID", 

编辑：SQL命令不能正常在下一行结束错误@AlexPoole，我添加了JOIN和清理SELECT但现在得到一个ORA-02287：这里不允许的序列号

(c.CatCode || '-' || 
(SELECT lpad(
(CASE substr(c.CatCode,0,3) 
WHEN 'AEG' THEN AEG_seq.NEXTVAL 
WHEN 'ARY' THEN ARY_seq.NEXTVAL 
WHEN 'BBR' THEN BBR_seq.NEXTVAL 
WHEN 'BSY' THEN BSY_seq.NEXTVAL 
... 
WHEN 'SDR' THEN SDR_seq.NEXTVAL 
WHEN 'SLC' THEN SLC_seq.NEXTVAL 
WHEN 'SLD' THEN SLD_seq.NEXTVAL 
WHEN 'SMS' THEN SMS_seq.NEXTVAL 
WHEN 'SPP' THEN SPP_seq.NEXTVAL 
WHEN 'SPR' THEN SPR_seq.NEXTVAL 
WHEN 'SRL' THEN SRL_seq.NEXTVAL 
ELSE 0 END),6,0) FROM DUAL)) as "ItemID", 
... 
FROM md_draw d 
join draw_catcodes c on d.series = c.series and d.base = c.base 
order by lpad(d.series,3,0), lpad(d.base,3,0), lpad(d.suffix,2,0); 

有什么建议吗？

编辑：@AlexPoole，你说得对，我取出包含序列调用你详细介绍它的子查询，但仍得到ORA-02287：序列号这里不允许错误：

SELECT 
(CASE d.image WHEN 0 THEN 'NoImage.pdf' 
ELSE lower(d.prefix || lpad(d.series,3,0) || lpad(d.base,3,0) || lpad(d.suffix,2,0) || lpad(d.rev,2,0) || '.pdf') END) as "Filename", 
c.EngDiscipline as "EngDiscipline", 
c.CatCode || '-' || lpad(CASE substr(c.CatCode,0,3) 
WHEN 'AEG' THEN AEG_seq.NEXTVAL 
WHEN 'ARY' THEN ARY_seq.NEXTVAL 
WHEN 'BBR' THEN BBR_seq.NEXTVAL 
... 
WHEN 'SPP' THEN SPP_seq.NEXTVAL 
WHEN 'SPR' THEN SPR_seq.NEXTVAL 
WHEN 'SRL' THEN SRL_seq.NEXTVAL 
ELSE 0 END,6,'0') as "ItemID", 
upper(d.prefix || '-' || lpad(d.series,3,0) || '-' || lpad(d.base,3,0) || '-' || lpad(d.suffix,2,0)) as "LegacyID", 
    ... 
FROM md_draw SAMPLE (1) d 
join draw_catcodes c on d.series = c.series and d.base = c.base 
order by c.ccProgram, lpad(d.series,3,0), lpad(d.base,3,0), lpad(d.suffix,2,0); 

Answer 1

它相当容易。在PL/SQL中，查询既可以是游标，也可以选择转换为;在此，到您的绑定变量：

VARIABLE FullCatCode VARCHAR2(7) 

exec SELECT CatCode into :FullCatCode from draw_catcodes where series = 123 and base = 158; 

SELECT :FullCatCode || '-' || Other stuff... from table_name... 

如果你只打算使用它在以后的SQL语句，你也可以使用一个替代变量，而不是一个绑定变量：

COLUMN CatCode NEW_VALUE FullCatCode 

SELECT CatCode from draw_catcodes where series = 123 and base = 158; 

SELECT &FullCatCode || '-' || Other stuff... from table_name... 

---

随着您的修改问题，这不是你想要做的。您试图在同一查询的另一部分中引用子查询中的值，而不是稍后在脚本中的单独语句。并没有涉及PL/SQL。

你不能用上述任何一种机制来做到这一点;第一个是因为没有PL/SQL块执行select ... into，第二个是因为替换变量在语句运行之前被评估和替换 - new_value直到查询运行之后才存在。

你不想在这里一个子查询，虽然，你应该使用一个连接，像这样：

SELECT 
    CASE d.image WHEN 0 THEN 'NoImage.pdf' 
    ELSE lower(d.prefix || lpad(d.series,3,'0') || lpad(d.base,3,'0') || lpad(d.suffix,2,'0') || lpad(d.rev,2,'0') || '.pdf') 
    END as "Filename", 
    c.EngDiscipline as "EngDiscipline", 
    c.CatCode, -- not sure if you actually want this raw value? 
    c.CatCode || '-' || lpad(CASE substr(c.CatCode,0,3) 
    WHEN 'AEG' THEN AEG_seq.NEXTVAL 
    WHEN 'ARY' THEN ARY_seq.NEXTVAL 
    WHEN 'BBR' THEN BBR_seq.NEXTVAL 
    ELSE 0 
    END,6,'0') as "ItemID", 
    upper(d.prefix || '-' || lpad(d.series,3,'0') || '-' || lpad(d.base,3,'0') || '-' || lpad(d.suffix,2,'0')) 
    as "LegacyID", 
    ... 
from tablename d 
join draw_catcodes c on d.series = c.series and d.base = c.base 
where ... 

您可以直接引用c.CatCode在你试图使用&FullCatCode的地方。

如果序列只存在于这个查询和项目Id没有更广泛的意义，你可以使用一个解析函数生成ItemIds代替：

c.CatCode || '-' || 
    lpad(row_number() over (partition by substr(c.CatCode,0,3) order by null),6,'0') 
    as "ItemID", 

届时将有ItemIds不确定性的排序，但不会有序列方法;通过这个，你可以修改窗口子句来指定顺序，如果这是可取的。