oracle 如何获得oracle表中的第一列？
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How can I get first column in oracle table?
提问by Gaurav
I need to get first column in a oracle table for my select query i.e. SELECT FIRST_COLUMN from TABLE. How can I do this? I do not have access to SYS tables i.e no access to tables like user_tab_columns. Is it possible to do so?
我需要为我的选择查询获取 oracle 表中的第一列，即 SELECT FIRST_COLUMN from TABLE。我怎样才能做到这一点？我无权访问 SYS 表，即无法访问像 user_tab_columns 这样的表。有可能这样做吗？
回答by Gary Myers
You ALWAYS have access to USER_TAB_COLUMNS.
您始终有权访问 USER_TAB_COLUMNS。
Too much stuff breaks if the DBA tries to revoke it.
如果 DBA 试图撤销它，太多的东西就会中断。
回答by stjohnroe
Sounds like you have very limited access. If your accounts has access to DBMS_SQL you could try the following:
听起来您的访问权限非常有限。如果您的帐户可以访问 DBMS_SQL，您可以尝试以下操作：
declare
lv_stat VARCHAR2(300) := 'SELECT * FROM tablename';
lv_cid integer;
lv_tab DBMS_SQL.DESC_TAB;
lv_cnt int;
begin
lv_cid := DBMS_SQL.OPEN_CURSOR;
DBMS_SQL.PARSE(lv_cid,lv_stat,DBMS_SQL.NATIVE);
DBMS_SQL.DESCRIBE_COLUMNS(lv_cid,lv_cnt,lv_tab);
DBMS_OUTPUT.PUT_LINE('First Column is '||lv_tab(1).col_name);
DBMS_SQL.CLOSE_CURSOR(lv_cid);
EXCEPTION
when others then
DBMS_SQL.CLOSE_CURSOR(lv_cid);
end;
This could be wrapped into a PL/SQL function. Probably simpler to talk to your DBAs
这可以包装到一个 PL/SQL 函数中。与您的 DBA 交谈可能更简单
