解析如何查看Oracle数据库中某张表的字段个数

select count(column_name) from user_tab_columns where table_name='T_B_AUDITOR'

64 T_A_BOOKSTAGEINFO 4
65 T_B_AUDITOR 14
66 T_B_BOOKMANAGEMENT 13
67 T_B_BOOKSTATUSCONFIG 5
68 T_B_CODETREEINFO 8
69 T_B_FILTERWORD 11
70 T_B_ISBNWHITELIST 11
71 T_B_MODEL 10
72 T_B_NOTICE 15
73 T_B_NOTICEACCEPT 11
74 T_B_OPERLOG 10
75 T_B_ORGANIZATIONINFO 18
76 T_B_PREFIXINFO 15
77 T_B_PUBLISHINFO 30
78 T_B_ROLE 8
79 T_B_ROLEMODEL 6
80 T_B_SAMPLEBOOKINFO 89
81 T_B_USER 26
82 T_B_USERANDROLE 6
83 T_B_USERLOGIN 8
84 T_B_USERMODEL 6

mysql> desc test;
+---------+-------------+------+-----+---------+----------------+
| Field   | Type        | Null | Key | Default | Extra          |
+---------+-------------+------+-----+---------+----------------+
| id      | int(11)     | NO   | PRI | NULL    | auto_increment |
| name    | varchar(10) | YES  |     | NULL    |                |
| address | varchar(30) | YES  |     | NULL    |                |
+---------+-------------+------+-----+---------+----------------+
3 rows in set (0.01 sec)
mysql> select found_rows();
+--------------+
| found_rows() |
+--------------+
|            3 |
+--------------+
1 row in set (0.01 sec)

mysql> use information_schema
Database changed
mysql> select count() from columns where table_name="test";
+----------+
| count() |
+----------+
|        3 |
+----------+
1 row in set (0.00 sec)

mysql> select from schemata;
+--------------+--------------------+----------------------------+------------------------+----------+
| CATALOG_NAME | SCHEMA_NAME        | DEFAULT_CHARACTER_SET_NAME | DEFAULT_COLLATION_NAME | SQL_PATH |
+--------------+--------------------+----------------------------+------------------------+----------+
| NULL         | information_schema | utf8                       | utf8_general_ci        | NULL     |
| NULL         | mysql              | utf8                       | utf8_general_ci        | NULL     |
| NULL         | test               | utf8                       | utf8_general_ci        | NULL     |
+--------------+--------------------+----------------------------+------------------------+----------+
3 rows in set (0.00 sec)

mysql> select table_schema,count() from tables group by table_schema;
+--------------------+----------+
| table_schema       | count() |
+--------------------+----------+
| information_schema |       17 |
| mysql              |       17 |
| test               |        6 |
+--------------------+----------+
3 rows in set (0.00 sec)