Categories:

System functions (Information)

SYSTEM$GET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT

Returns the list of columns that were set by a previous call to SYSTEM$SET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT for the specified Snowflake view (for example, for a specific ACCOUNT_USAGE view or INFORMATION_SCHEMA view).

For more information, see Handling new columns in SHOW command output and Snowflake views.

See also:

SYSTEM$SET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT , SYSTEM$UNSET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT , SYSTEM$GET_ALL_DEFAULT_COLUMNS_OVERRIDES

语法

SYSTEM$GET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT(
  '<object_type>',
  '<database_name>',
  '<schema_name>',
  '<object_name>'
)

实参

'object_type'

Type of the object. You must specify 'VIEW' for this argument.

'database_name'

Name of the database that contains the object. You must specify 'SNOWFLAKE' or, for INFORMATION_SCHEMA views, an empty string.

'schema_name'

Name of the schema that contains the object. You must specify the name of a schema in the SNOWFLAKE database or 'INFORMATION_SCHEMA'.

'object_name'

对象名称。

返回

返回一个 VARCHAR 值，其中包含前次调用 SYSTEM$SET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT 所指定的列的逗号分隔列表。列名称为大写。

If SYSTEM$SET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT was not called or if SYSTEM$UNSET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT was called to clear the list of columns, the function returns an empty string.

访问控制要求

只有账户管理员（被授予 ACCOUNTADMIN 角色的用户）可以调用此函数。

使用说明

  • You must have a database in use (for example, by running USE DATABASE) in order to call this function. If no database is in use, the function call fails.

示例

The following example returns the list of columns specified by a previous call to SYSTEM$SET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT for the TABLES view in the ACCOUNT_USAGE schema:

SELECT SYSTEM$GET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT(
  'VIEW',
  'SNOWFLAKE',
  'ACCOUNT_USAGE',
  'TABLES'
);
+--------------------------------------------------------+
| SYSTEM$GET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT( |
|   'VIEW',                                              |
|   'SNOWFLAKE',                                         |
|   'ACCOUNT_USAGE',                                     |
|   'TABLES'                                             |
| )                                                      |
%--------------------------------------------------------%
| TABLE_NAME,TABLE_SCHEMA,TABLE_TYPE                     |
+--------------------------------------------------------+

The following example returns the list of columns specified by a previous call to SYSTEM$SET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT for the TABLES view in the INFORMATION_SCHEMA schema:

SELECT SYSTEM$GET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT(
  'VIEW',
  '',
  'ACCOUNT_USAGE',
  'TABLES'
);
+--------------------------------------------------------+
| SYSTEM$GET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT( |
|   'VIEW',                                              |
|   '',                                                  |
|   'INFORMATION_SCHEMA',                                |
|   'TABLES'                                             |
| )                                                      |
%--------------------------------------------------------%
| TABLE_NAME,TABLE_SCHEMA,TABLE_TYPE                     |
+--------------------------------------------------------+

如果未调用 SYSTEM$SET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT，或者如果调用 SYSTEM$UNSET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT 以清除列表，该函数会返回一个空字符串：

SELECT SYSTEM$UNSET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT(
  'VIEW',
  'SNOWFLAKE',
  'ACCOUNT_USAGE',
  'TABLES'
);

SELECT SYSTEM$GET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT(
  'VIEW',
  'SNOWFLAKE',
  'ACCOUNT_USAGE',
  'TABLES'
);
+--------------------------------------------------------+
| SYSTEM$GET_DEFAULT_COLUMNS_OVERRIDE_FOR_SYSTEM_OBJECT( |
|   'VIEW',                                              |
|   'SNOWFLAKE',                                         |
|   'ACCOUNT_USAGE',                                     |
|   'TABLES'                                             |
| )                                                      |
%--------------------------------------------------------%