Oracle 查询以获取列名
我有一个 mySQL 查询来从这样的表中获取列:
I have a mySQL query to get columns from a table like this:
String sqlStr="select column_name
from information_schema.COLUMNS
where table_name='users'
and table_schema='"+_db+"'
and column_name not in ('password','version','id')"
如何在 Oracle 11g 数据库中更改上述查询?我需要获取列名称作为表用户"的结果集，不包括某些列，指定模式.现在我的新表空间中有所有表，那么我是否指定表空间名称代替模式名称?
How do I change the above query in Oracle 11g database? I need to get columns names as a resultset for table 'users' excluding certain columns, specifying a schema. Right now I have all tables in my new tablespace, so do I specify tablespace name in place of schema name?
还有一个通用的 HQL 吗?在我的新 Oracle 数据库中(我是 Oracle 的新手)，我只有表空间名称，所以这相当于模式名称(逻辑上?)
Also is there a generic HQL for this? In my new Oracle database (I am new to Oracle), I only have tablespace name, so is that equivalent to schema name (logically?)
推荐答案
information_schema.COLUMNS 的 Oracle 等价物是 USER_TAB_COLS 对于当前用户拥有的表，ALL_TAB_COLS 或 DBA_TAB_COLS 适用于所有用户拥有的表.
The Oracle equivalent for information_schema.COLUMNS is USER_TAB_COLS for tables owned by the current user, ALL_TAB_COLS or DBA_TAB_COLS for tables owned by all users.
表空间不等同于模式，您也不必提供表空间名称.
Tablespace is not equivalent to a schema, neither do you have to provide the tablespace name.
如果您想查询 ALL_TAB_COLS 或 DBA_TAB_COLS 以获取特定用户拥有的 OF 表列，则提供架构/用户名将很有用.在你的情况下，我想查询看起来像:
Providing the schema/username would be of use if you want to query ALL_TAB_COLS or DBA_TAB_COLS for columns OF tables owned by a specific user. in your case, I'd imagine the query would look something like:
String sqlStr= "
SELECT column_name
FROM all_tab_cols
WHERE table_name = 'USERS'
AND owner = '" +_db+ "'
AND column_name NOT IN ( 'PASSWORD', 'VERSION', 'ID' )"
请注意，使用这种方法，您可能会面临 SQL 注入的风险.
Note that with this approach, you risk SQL injection.
大写表名和列名，因为它们在 Oracle 中通常是大写的；如果用双引号将它们括起来，它们只能是小写或混合大小写.
Uppercased the table- and column names as these are typically uppercase in Oracle; they are only lower- or mixed case if created with double quotes around them.
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