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sp_columns_ex (Transact-SQL)

  • Стаття

Applies to: SQL Server

Returns the column information, one row per column, for the specified linked server tables. sp_columns_ex returns column information for only the specific column if @column_name is specified.

Transact-SQL syntax conventions

Syntax

sp_columns_ex
    [ @table_server = ] N'table_server'
    [ , [ @table_name = ] N'table_name' ]
    [ , [ @table_schema = ] N'table_schema' ]
    [ , [ @table_catalog = ] N'table_catalog' ]
    [ , [ @column_name = ] N'column_name' ]
    [ , [ @ODBCVer = ] ODBCVer ]
[ ; ]

Arguments

[ @table_server = ] N'table_server'

The name of the linked server for which to return column information. @table_server is sysname, with no default.

[ @table_name = ] N'table_name'

The name of the table for which to return column information. @table_name is sysname, with a default of NULL.

[ @table_schema = ] N'table_schema'

The schema name of the table for which to return column information. @table_schema is sysname, with a default of NULL.

[ @table_catalog = ] N'table_catalog'

The catalog name of the table for which to return column information. @table_catalog is sysname, with a default of NULL.

[ @column_name = ] N'column_name'

The name of the database column for which to provide information. @column_name is sysname, with a default of NULL.

[ @ODBCVer = ] ODBCVer

The version of ODBC that is being used. @ODBCVer is int, with a default of 2. This indicates ODBC Version 2. Valid values are 2 or 3. For information about the behavior differences between versions 2 and 3, see the ODBC SQLColumns specification.

Return code values

None.

Result set

Column name Data type Description
TABLE_CAT sysname Table or view qualifier name. Various DBMS products support three-part naming for tables (<qualifier>.<owner>.<name>). In SQL Server this column represents the database name. In some products, it represents the server name of the table's database environment. This field can be NULL.
TABLE_SCHEM sysname Table or view owner name. In SQL Server, this column represents the name of the database user that created the table. This field always returns a value.
TABLE_NAME sysname Table or view 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 An int value that corresponds to ODBC type indicators. If this is a data type that can't be mapped to an ODBC type, this value is NULL. The native data type name is returned in the TYPE_NAME column.
TYPE_NAME varchar(13) String representing a data type. The underlying DBMS presents this data type name.
COLUMN_SIZE int Number of significant digits. The return value for the PRECISION column is in base 10.
BUFFER_LENGTH int Transfer size of the data.1
DECIMAL_DIGITS smallint Number of digits to the right of the decimal point.
NUM_PREC_RADIX smallint The 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 varchar(254) 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 interval data 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 table. The first column in the table is 1. This column always returns a value.
IS_NULLABLE varchar(254) Nullability of the column in the table. ISO rules are followed to determine nullability. An ISO SQL-compliant DBMS can't return an empty string.

YES = Column can include NULL.
NO = Column can't include NULL.

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 ODBC Overview.

Remarks

  • sp_columns_ex is executed by querying the COLUMNS rowset of the IDBSchemaRowset interface of the OLE DB provider corresponding to @table_server. The @table_name, @table_schema, @table_catalog, and @column_name parameters are passed to this interface to restrict the rows returned.

  • sp_columns_ex returns an empty result set if the OLE DB provider of the specified linked server doesn't support the COLUMNS rowset of the IDBSchemaRowset interface.

  • sp_columns_ex follows the requirements for delimited identifiers. For more information, see Database identifiers.

Permissions

Requires SELECT permission on the schema.

Examples

The following example returns the data type of the JobTitle column of the HumanResources.Employee table in the AdventureWorks2022 database on the linked server Seattle1.

EXEC sp_columns_ex 'Seattle1',
    'Employee',
    'HumanResources',
    'AdventureWorks2022',
    'JobTitle';

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