# db2_special_columns

(PECL ibm_db2:1.0-1.6.2)

db2_special_columns — Returns a result set listing the unique row identifier columns for a table

### Description

resource db2_special_columns ( resource `$connection` , string `$qualifier` , string `$schema` , string `$table_name` , int `$scope` )

Returns a result set listing the unique row identifier columns for a table.

### Parameters

`connection`

  A valid connection to an IBM DB2, Cloudscape, or Apache Derby database.

`qualifier`

  A qualifier for DB2 databases running on OS/390 or z/OS servers. For other databases, pass `NULL` or an empty string.

`schema`

  The schema which contains the tables.

`table_name`

  The name of the table.

`scope`

  Integer value representing the minimum duration for which the unique row identifier is valid. This can be one of the following values:

  Integer value | SQL constant | Description
  --- | --- | ---
  0 | SQL_SCOPE_CURROW | Row identifier is valid only while the cursor is positioned on the row.
  1 | SQL_SCOPE_TRANSACTION | Row identifier is valid for the duration of the transaction.
  2 | SQL_SCOPE_SESSION | Row identifier is valid for the duration of the connection.

### Return Values

Returns a statement resource with a result set containing rows with unique row identifier information for a table. The rows are composed of the following columns:

Column name | Description
--- | ---
SCOPE |
Integer value | SQL constant | Description
--- | --- | ---
0 | SQL_SCOPE_CURROW | Row identifier is valid only while the cursor is positioned on the row.
1 | SQL_SCOPE_TRANSACTION | Row identifier is valid for the duration of the transaction.
2 | SQL_SCOPE_SESSION | Row identifier is valid for the duration of the connection.
COLUMN_NAME | Name of the unique column.
DATA_TYPE | SQL data type for the column.
TYPE_NAME | Character string representation of the SQL data type for the column.
COLUMN_SIZE | An integer value representing the size of the column.
BUFFER_LENGTH | Maximum number of bytes necessary to store data from this column.
DECIMAL_DIGITS | The scale of the column, or `NULL` where scale is not applicable.
NUM_PREC_RADIX | An integer value of either 10 (representing an exact numeric data type), 2 (representing an approximate numeric data type), or `NULL` (representing a data type for which radix is not applicable).
PSEUDO_COLUMN | Always returns 1.

### See Also

- db2_column_privileges()
- db2_columns()
- db2_foreign_keys()
- db2_primary_keys()
- db2_procedure_columns()
- db2_procedures()
- db2_statistics()
- db2_table_privileges()
- db2_tables()