获取列的列 table

Question

如何获取 INFORMATION_SCHEMA.COLUMNS 视图的列列表？

我可以获取我创建的任何 table 的列：

select *
from information_schema.columns
where table_name = 'MY_TABLE'

结果集包含多列，如：

TABLE_CATALOG
TABLE_SCHEMA
TABLE_NAME
COLUMN_NAME
DATA_TYPE
等等

如何获得这些列的完整列表？ COLUMNS 视图似乎不包含其列本身（如在 Oracle、PostgreSQL 或 MySQL 中）。如果我运行:

select * 
from information_schema.columns
where table_name = 'COLUMNS'

我一无所获。可能我找错地方了。

Answer 1

使用sys.dm_exec_describe_first_result_set：

SELECT *
FROM sys.dm_exec_describe_first_result_set(
     N'SELECT * FROM INFORMATION_SCHEMA.COLUMNS', NULL, 0);

db<>fiddle demo

Answer 2

SQL 服务器在 sys 模式下保存其元数据。
INFORMATION_SCHEMA 后来作为 SQL ISO 合规性的一部分添加。

select   s.name as schema_name
        ,o.name as table_name
        ,c.name as column_name
        ,t.name as type_name
from         sys.schemas        s
        join sys.all_objects    o on o.schema_id = s.schema_id
        join sys.all_columns    c on c.object_id = o.object_id
        join sys.types          t on t.system_type_id = c.system_type_id and t.user_type_id = c.user_type_id
where   s.name = 'INFORMATION_SCHEMA'
    and o.name = 'COLUMNS'

.

+--------------------+------------+--------------------------+-----------+
|    schema_name     | table_name |       column_name        | type_name |
+--------------------+------------+--------------------------+-----------+
| INFORMATION_SCHEMA | COLUMNS    | TABLE_CATALOG            | nvarchar  |
| INFORMATION_SCHEMA | COLUMNS    | TABLE_SCHEMA             | nvarchar  |
| INFORMATION_SCHEMA | COLUMNS    | TABLE_NAME               | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | COLUMN_NAME              | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | ORDINAL_POSITION         | int       |
| INFORMATION_SCHEMA | COLUMNS    | COLUMN_DEFAULT           | nvarchar  |
| INFORMATION_SCHEMA | COLUMNS    | IS_NULLABLE              | varchar   |
| INFORMATION_SCHEMA | COLUMNS    | DATA_TYPE                | nvarchar  |
| INFORMATION_SCHEMA | COLUMNS    | CHARACTER_MAXIMUM_LENGTH | int       |
| INFORMATION_SCHEMA | COLUMNS    | CHARACTER_OCTET_LENGTH   | int       |
| INFORMATION_SCHEMA | COLUMNS    | NUMERIC_PRECISION        | tinyint   |
| INFORMATION_SCHEMA | COLUMNS    | NUMERIC_PRECISION_RADIX  | smallint  |
| INFORMATION_SCHEMA | COLUMNS    | NUMERIC_SCALE            | int       |
| INFORMATION_SCHEMA | COLUMNS    | DATETIME_PRECISION       | smallint  |
| INFORMATION_SCHEMA | COLUMNS    | CHARACTER_SET_CATALOG    | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | CHARACTER_SET_SCHEMA     | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | CHARACTER_SET_NAME       | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | COLLATION_CATALOG        | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | COLLATION_SCHEMA         | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | COLLATION_NAME           | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | DOMAIN_CATALOG           | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | DOMAIN_SCHEMA            | sysname   |
| INFORMATION_SCHEMA | COLUMNS    | DOMAIN_NAME              | sysname   |
+--------------------+------------+--------------------------+-----------+

获取列的列 table

Get columns of the columns table

sql

metadata

sql-server-2014