mysql
USE information_schema; --切记这里不能忘掉
SELECT
T.TABLE_SCHEMA AS '数据库名称',
T.TABLE_NAME AS '表名',
T.TABLE_TYPE AS '表类型',
T. ENGINE AS '数据库引擎',
C.ORDINAL_POSITION AS '字段编号',
C.COLUMN_NAME AS '字段名',
C.COLUMN_TYPE AS '数据类型',
C.IS_NULLABLE AS '允许为空',
C.COLUMN_KEY AS '键类型',
C.EXTRA AS '自增属性',
C.CHARACTER_SET_NAME AS '编码名称',
C.COLUMN_COMMENT AS '字段说明'
FROM
COLUMNS C
INNER JOIN TABLES T ON C.TABLE_SCHEMA = T.TABLE_SCHEMA
AND C.TABLE_NAME = T.TABLE_NAME
WHERE T.TABLE_SCHEMA = 'mysql' --这里mysql指代的是库的名称,也可以在后面添加排序条件这里
就不多说了
oracle
SELECT
col.COLUMN_NAME 字段名称,
com.Comments 字段说明,
col.DATA_TYPE 数据类型,
col.DATA_LENGTH 长度,
col.NULLABLE 能否为空
FROM
sys.all_tab_columns col,
sys.all_col_comments com
WHERE
col. OWNER = 'ONCCC'(用户名)
AND col.table_name = 'T_MM_USER'(表名)
AND com. OWNER (+) = 'ONCCC'用户名)
AND com.Table_Name (+) = 'T_MM_USER'(表名)
AND com.Column_Name (+) = col.Column_Name
ORDER BY
col.column_id
如果不知道用户名,可用以下sql查询
SELECT username,default_tablespace FROM user_users