SQL> select column_name,data_type from user_tab_columns where table_name='student';COLUMN_NAME DATA_TYPE ------------------------------ -------------------------------------------------------------------------------- SQL> select column_name,data_type from user_tab_columns where table_name='STUDENT';COLUMN_NAME DATA_TYPE ------------------------------ -------------------------------------------------------------------------------- ID VARCHAR2 SNAME VARCHAR2 BOOK VARCHAR2
也可以这样SQL> desc student; Name Type Nullable Default Comments ----- ------------ -------- ------- -------- ID VARCHAR2(10) Y SNAME VARCHAR2(20) Y BOOK VARCHAR2(20) Y
对,oracle系统视图中类似的表名、列名等等,一律都要用大写的名称。
大小写造成的,这样写就可以不区分大小写返回 select column_name,data_type from user_tab_columns where lower(table_name)='tbl'
V$ dynamic performance view 里面数据主要是小写,而dba_, user_等static data dictionary 里面的数据主要是大写。
------------------------------ --------------------------------------------------------------------------------
SQL> select column_name,data_type from user_tab_columns where table_name='STUDENT';COLUMN_NAME DATA_TYPE
------------------------------ --------------------------------------------------------------------------------
ID VARCHAR2
SNAME VARCHAR2
BOOK VARCHAR2
Name Type Nullable Default Comments
----- ------------ -------- ------- --------
ID VARCHAR2(10) Y
SNAME VARCHAR2(20) Y
BOOK VARCHAR2(20) Y
select column_name,data_type from user_tab_columns where lower(table_name)='tbl'