SqlServer中常常搞不清楚 sp_columns来看一看

The sp_columns catalog stored procedure is equivalent to SQLColumns in ODBC. The results returned are ordered by TABLE_QUALIFIER, TABLE_OWNER, and TABLE_NAME.

Column name	Data type	Description
TABLE_QUALIFIER	sysname	Object qualifier name. This field can be NULL.
TABLE_OWNER	sysname	Object owner name. This field always returns a value.
TABLE_NAME	sysname	Object name. This field always returns a value.
COLUMN_NAME	sysname	Column name, for each column of the TABLE_NAME returned. This field always returns a value.
DATA_TYPE	smallint	Integer code for ODBC data type. If this is a data type that cannot be mapped to an ODBC type, it is NULL. The native data type name is returned in the TYPE_NAMEcolumn.
TYPE_NAME	sysname	String representing a data type. The underlying DBMS presents this data type name.
PRECISION	int	Number of significant digits. The return value for the PRECISION column is in base 10.
LENGTH	int	Transfer size of the data.1
SCALE	smallint	Number of digits to the right of the decimal point.
RADIX	smallint	Base for numeric data types.
NULLABLE	smallint	Specifies nullability. 1 = NULL is possible. 0 = NOT NULL.
REMARKS	varchar(254)	This field always returns NULL.
COLUMN_DEF	nvarchar(4000)	Default value of the column.
SQL_DATA_TYPE	smallint	Value of the SQL data type as it appears in the TYPE field of the descriptor. This column is the same as the DATA_TYPE column, except for the datetime and SQL-92 intervaldata types. This column always returns a value.
SQL_DATETIME_SUB	smallint	Subtype code for datetime and SQL-92 interval data types. For other data types, this column returns NULL.
CHAR_OCTET_LENGTH	int	Maximum length in bytes of a character or integer data type column. For all other data types, this column returns NULL.
ORDINAL_POSITION	int	Ordinal position of the column in the object. The first column in the object is 1. This column always returns a value.
IS_NULLABLE	varchar(254)	Nullability of the column in the object. ISO rules are followed to determine nullability. An ISO SQL-compliant DBMS cannot return an empty string. YES = Column can include NULLS. NO = Column cannot include NULLS. This column returns a zero-length string if nullability is unknown. The value returned for this column is different from the value returned for the NULLABLE column.
SS_DATA_TYPE	tinyint	SQL Server data type used by extended stored procedures. For more information, see Data Types (Transact-SQL).

1 For more information, see the Microsoft ODBC documentation.