COLUMNS (Transact-SQL)

THIS TOPIC APPLIES TO: yesSQL Server (starting with 2008)yesAzure SQL DatabaseyesAzure SQL Data Warehouse yesParallel Data Warehouse

Returns one row for each column that can be accessed by the current user in the current database.

To retrieve information from these views, specify the fully qualified name of INFORMATION_SCHEMA.view_name.

Column name Data type Description
TABLE_CATALOG nvarchar(128) Table qualifier.
TABLE_SCHEMA nvarchar(128) Name of schema that contains the table.

** Important *\* Do not use INFORMATION_SCHEMA views to determine the schema of an object. The only reliable way to find the schema of a object is to query the sys.objects catalog view.
TABLE_NAME nvarchar(128) Table name.
COLUMN_NAME nvarchar(128) Column name.
ORDINAL_POSITION int Column identification number.
COLUMN_DEFAULT nvarchar(4000) Default value of the column.
IS_NULLABLE varchar(3) Nullability of the column. If this column allows for NULL, this column returns YES. Otherwise, NO is returned.
DATA_TYPE nvarchar(128) System-supplied data type.
CHARACTER_MAXIMUM_LENGTH int Maximum length, in characters, for binary data, character data, or text and image data.

-1 for xml and large-value type data. Otherwise, NULL is returned. For more information, see Data Types (Transact-SQL).
CHARACTER_OCTET_LENGTH int Maximum length, in bytes, for binary data, character data, or text and image data.

-1 for xml and large-value type data. Otherwise, NULL is returned.
NUMERIC_PRECISION tinyint Precision of approximate numeric data, exact numeric data, integer data, or monetary data. Otherwise, NULL is returned.
NUMERIC_PRECISION_RADIX smallint Precision radix of approximate numeric data, exact numeric data, integer data, or monetary data. Otherwise, NULL is returned.
NUMERIC_SCALE int Scale of approximate numeric data, exact numeric data, integer data, or monetary data. Otherwise, NULL is returned.
DATETIME_PRECISION smallint Subtype code for datetime and ISO interval data types. For other data types, NULL is returned.
CHARACTER_SET_CATALOG nvarchar(128) Returns master. This indicates the database in which the character set is located, if the column is character data or text data type. Otherwise, NULL is returned.
CHARACTER_SET_SCHEMA nvarchar(128) Always returns NULL.
CHARACTER_SET_NAME nvarchar(128) Returns the unique name for the character set if this column is character data or text data type. Otherwise, NULL is returned.
COLLATION_CATALOG nvarchar(128) Always returns NULL.
COLLATION_SCHEMA nvarchar(128) Always returns NULL.
COLLATION_NAME nvarchar(128) Returns the unique name for the collation if the column is character data or text data type. Otherwise, NULL is returned.
DOMAIN_CATALOG nvarchar(128) If the column is an alias data type, this column is the database name in which the user-defined data type was created. Otherwise, NULL is returned.
DOMAIN_SCHEMA nvarchar(128) If the column is a user-defined data type, this column returns the name of the schema of the user-defined data type. Otherwise, NULL is returned.

** Important *\* Do not use INFORMATION_SCHEMA views to determine the schema of a data type. The only reliable way to find the schema of a type is to use the TYPEPROPERTY function.
DOMAIN_NAME nvarchar(128) If the column is a user-defined data type, this column is the name of the user-defined data type. Otherwise, NULL is returned.

Remarks

The ORDINAL_POSITION column of the INFORMATION_SCHEMA.COLUMNS view is not compatible with the bit pattern of columns returned by the COLUMNS_UPDATED function. To obtain a bit pattern that is compatible with COLUMNS_UPDATED, you must reference the ColumnID property of the COLUMNPROPERTY system function when you query the INFORMATION_SCHEMA.COLUMNS view. For example:

USE AdventureWorks2012;  
GO  
SELECT TABLE_NAME, COLUMN_NAME, COLUMNPROPERTY(OBJECT_ID(TABLE_SCHEMA + '.' + TABLE_NAME), COLUMN_NAME, 'ColumnID') AS COLUMN_ID  
FROM AdventureWorks2012.INFORMATION_SCHEMA.COLUMNS  
WHERE TABLE_NAME = 'Person';  
GO  

See Also

System Views (Transact-SQL)
Information Schema Views (Transact-SQL)
sys.syscharsets (Transact-SQL)
sys.columns (Transact-SQL)
sys.sql_modules (Transact-SQL)
sys.configurations (Transact-SQL)
sys.objects (Transact-SQL)
sys.types (Transact-SQL)
COLUMNS_UPDATED (Transact-SQL)