# SYSCOLUMNS system table

Describes the columns within all tables in the current database:

Column Name | Type | Length | Nullable | Contents
--- | --- | --- | --- | ---
REFERENCEID | CHAR | 36 | false | Identifier for table (join with SYSTABLES.TABLEID)
COLUMNNAME | CHAR | 128 | false | Column or parameter name
COLUMNNUMBER | INT | 4 | false | The position of the column within the table
COLUMNDATATYPE | org.apache.derby.catalog. TypeDescriptor This class is not part of the public API. |  | false | System type that describes precision, length, scale, nullability, type name, and storage type of data. For a user-defined type, this column can hold a TypeDescriptor that refers to the appropriate type alias in SYS.SYSALIASES.
COLUMNDEFAULT | java.io.Serializable |  | true | For tables, describes default value of the column. The toString() method on the object stored in the table returns the text of the default value as specified in the CREATE TABLE or ALTER TABLE statement.
COLUMNDEFAULTID | CHAR | 36 | true | Unique identifier for the default value
AUTOINCREMENT COLUMNVALUE | BIGINT |  | true | What the next value for column will be, if the column is an identity column
AUTOINCREMENT COLUMNSTART | BIGINT |  | true | Initial value of column (if specified), if it is an identity column
AUTOINCREMENT COLUMNINC | BIGINT |  | true | Amount column value is automatically incremented (if specified), if the column is an identity column

Parent topic: Derby system tables