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3.1.4.2.2.1.3.4.1 Columns

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The DBSCHEMA_PROVIDER_TYPES rowset contains the following columns.

Name

Type

Restriction

Description

TYPE_NAME

xsd:string

The server-specific data type name.<203>

DATA_TYPE

xsd:unsignedShort

Yes

This enumeration is the same as LEVEL_DBTYPE for MDSCHEMA_LEVELS. (See section 3.1.4.2.2.1.3.8)

COLUMN_SIZE

xsd:unsignedInt

The length of a non-numeric column or parameter that refers to either the maximum or the length defined for this type by the server. For character data, this is the maximum or defined length in characters. For DateTime data types, this is the length of the string representation (assuming the maximum allowed precision of the fractional second component).

If the data type is numeric, this is the upper bound on the maximum precision of the data type.

LITERAL_PREFIX

xsd:string

The character or characters used to prefix a literal of this type in a text command.

LITERAL_SUFFIX

xsd:string

The character or characters used to suffix a literal of this type in a text command.

CREATE_PARAMS

xsd:string

The creation parameters specified by the consumer when creating a column of this data type. For example, the SQL DECIMAL data type needs a precision and a scale. In this case, the creation parameters might be the string "precision,scale". In a text command to create a DECIMAL column with a precision of 10 and a scale of 2, the value of the TYPE_NAME column might be DECIMAL(), and the complete type specification would be DECIMAL(10,2).

The creation parameters appear as a comma-separated list of values, in the order they are to be supplied and with no surrounding parentheses. If a creation parameter is length, maximum length, precision, scale, seed, or increment, use "length", "max length", "precision", "scale", "seed", and "increment", respectively. If the creation parameter is some other value, the server determines what text is to be used to describe the creation parameter.

If the data type requires creation parameters, "()" usually appears in the type name. This indicates the position at which to insert the creation parameters. If the type name does not include "()", the creation parameters are enclosed in parentheses and appended to the data type name.

IS_NULLABLE

xsd:boolean

A Boolean that indicates whether the data type is nullable.

  • True indicates that the data type is nullable.

  • False indicates that the data type is not nullable.

§ NULL indicates that it is not known whether the data type is nullable.<204>

CASE_SENSITIVE

xsd:boolean

A Boolean that indicates whether the data type is a character type and case-sensitive.

  • True indicates that the data type is a character type and is case-sensitive.

  • False indicates that the data type is not case-sensitive.

  • NULL indicates that the data type is not a character type.

SEARCHABLE

xsd:unsignedInt

An integer indicating how the data type can be used in searches if the server supports ICommandText; otherwise, NULL.

If the server supports ICommandText, then this column can have the following values:

  • DB_UNSEARCHABLE (0x01) - indicates that the data type cannot be used in a WHERE clause.

  • DB_LIKE_ONLY (0x02) - indicates that the data type can be used in a WHERE clause only with the LIKE predicate.

  • DB_ALL_EXCEPT_LIKE (0x03) - indicates that the data type can be used in a WHERE clause with all comparison operators except LIKE.

  • DB_SEARCHABLE (0x04) - indicates that the data type can be used in a WHERE clause with any comparison operator.<205>

UNSIGNED_ATTRIBUTE

xsd:boolean

A Boolean that indicates whether the data type is unsigned.

  • True indicates that the data type is unsigned.

  • False indicates that the data type is signed.

  • NULL indicates that this is not applicable to the data type.

FIXED_PREC_SCALE

xsd:boolean

A Boolean that indicates whether the data type has a fixed precision and scale.

  • True indicates that the data type has a fixed precision and scale.

  • False indicates that the data type does not have a fixed precision and scale.<206>

AUTO_UNIQUE_VALUE

xsd:boolean

A Boolean that indicates whether the data type can be autoincrementing.

  • True indicates that values of this type can be autoincrementing.

  • False indicates that values of this type cannot be autoincrementing.

  • If this value is true, the server's DBPROP_COL_AUTOINCREMENT column property determines whether a column of this type is always autoincrementing. If the DBPROP_COL_AUTOINCREMENT property is read/write, the setting of the DBPROP_COL_AUTOINCREMENT property determines whether a column of this type is autoincrementing. If DBPROP_COL_AUTOINCREMENT is a read-only property, either all or none of the columns of this type are autoincrementing.<207>

LOCAL_TYPE_NAME

xsd:string

The localized version of TYPE_NAME. NULL is returned if a localized name is not supported by the server.

MINIMUM_SCALE

xsd:short

If the type indicator is DBTYPE_VARNUMERIC, DBTYPE_DECIMAL, or DBTYPE_NUMERIC, this column specifies the minimum number of digits allowed to the right of the decimal point. Otherwise, it is NULL.

MAXIMUM_SCALE

xsd:short

If the type indicator is DBTYPE_VARNUMERIC, DBTYPE_DECIMAL, or DBTYPE_NUMERIC, this column specifies the maximum number of digits allowed to the right of the decimal point. Otherwise, it is NULL.

GUID

uuid

(Reserved for future use.)

The GUID of the type, if the type is described in a type library. Otherwise, it is NULL.

TYPELIB

xsd:string

The type library that contains the description of the type, if the type is described in a type library. Otherwise, it is NULL.

VERSION

xsd:string

The version of the type definition. Servers might request to create different versions of type definitions. Different servers might use different versioning schemes, such as a timestamp or a number (Integer or Float). NULL if not supported.

IS_LONG

xsd:boolean

A Boolean that indicates whether the data type is a binary large object (BLOB) and has very long data.

  • True indicates that the data type is a BLOB that contains very long data; the definition of very long data is server-specific.<208>

  • False indicates that the data type is a BLOB that does not contain very long data or that is not a BLOB.

This column value determines the setting of the DBCOLUMNFLAGS_ISLONG flag that is returned by GetColumnInfo in IColumnsInfo and the setting of the DBCOLUMNFLAGS_ISLONG flag that is returned by GetParameterInfo in ICommandWithParameters.

BEST_MATCH

xsd:boolean

Yes<209>

A Boolean that indicates whether the data type is the best match.

A value of true indicates that the data type is the best match between all data types in the data store and the OLE DB data type that is indicated by the value in the DATA_TYPE column. For more information, see [MSDN-OLEDB].

A value of false indicates that the data type is not the best match.

For each set of rows in which the value of the DATA_TYPE column is the same, the BEST_MATCH column is set to true in only one row.<210>

IS_FIXEDLENGTH

xsd:boolean

A Boolean that indicates whether the column is fixed in length.

A value of true indicates that columns of this type that are created by the DDL will be of fixed length.

A value of false indicates that columns of this type that are created by the DDL will be of variable length.

If the field is NULL, it is not known whether the server will map this field with a fixed-length or variable-length column.

The rowset is not sorted.

The response has the following definition.

      <xsd:element name="root">
         <xsd:complexType>
           <xsd:sequence minOccurs="0" maxOccurs="unbounded">
             <xsd:element name="row" type="row" />
           </xsd:sequence>
         </xsd:complexType>
       </xsd:element>
       <xsd:simpleType name="uuid">
         <xsd:restriction base="xsd:string">
           <xsd:pattern value="[0-9a-zA-Z]{8}-[0-9a-zA-Z]{4}-[0-9a-zA-Z]{4}-[0-9a-zA-Z]{4}-[0-9a-zA-Z]{12}" />
         </xsd:restriction>
       </xsd:simpleType>
       <xsd:complexType name="row">
         <xsd:sequence>
           <xsd:element sql:field="TYPE_NAME" name="TYPE_NAME" type="xsd:string" 
                        minOccurs="0" />
           <xsd:element sql:field="DATA_TYPE" name="DATA_TYPE" type="xsd:unsignedShort" 
                        minOccurs="0" />
           <xsd:element sql:field="COLUMN_SIZE" name="COLUMN_SIZE" type="xsd:unsignedInt" 
                        minOccurs="0" />
           <xsd:element sql:field="LITERAL_PREFIX" name="LITERAL_PREFIX" type="xsd:string" 
                        minOccurs="0" />
           <xsd:element sql:field="LITERAL_SUFFIX" name="LITERAL_SUFFIX" type="xsd:string" 
                        minOccurs="0" />
           <xsd:element sql:field="CREATE_PARAMS" name="CREATE_PARAMS" type="xsd:string" 
                        minOccurs="0" />
           <xsd:element sql:field="IS_NULLABLE" name="IS_NULLABLE" type="xsd:boolean" 
                        minOccurs="0" />
           <xsd:element sql:field="CASE_SENSITIVE" name="CASE_SENSITIVE" type="xsd:boolean" 
                        minOccurs="0" />
           <xsd:element sql:field="SEARCHABLE" name="SEARCHABLE" type="xsd:unsignedInt" 
                        minOccurs="0" />
           <xsd:element sql:field="UNSIGNED_ATTRIBUTE" name="UNSIGNED_ATTRIBUTE" 
                        type="xsd:boolean" minOccurs="0" />
           <xsd:element sql:field="FIXED_PREC_SCALE" name="FIXED_PREC_SCALE" 
                        type="xsd:boolean" minOccurs="0" />
           <xsd:element sql:field="AUTO_UNIQUE_VALUE" name="AUTO_UNIQUE_VALUE" 
                        type="xsd:boolean" minOccurs="0" />
           <xsd:element sql:field="LOCAL_TYPE_NAME" name="LOCAL_TYPE_NAME" type="xsd:string" 
                        minOccurs="0" />
           <xsd:element sql:field="MINIMUM_SCALE" name="MINIMUM_SCALE" type="xsd:short" 
                        minOccurs="0" />
           <xsd:element sql:field="MAXIMUM_SCALE" name="MAXIMUM_SCALE" type="xsd:short" 
                        minOccurs="0" />
           <xsd:element sql:field="GUID" name="GUID" type="uuid" minOccurs="0" />
           <xsd:element sql:field="TYPELIB" name="TYPELIB" type="xsd:string" minOccurs="0" />
           <xsd:element sql:field="VERSION" name="VERSION" type="xsd:string" minOccurs="0" />
           <xsd:element sql:field="IS_LONG" name="IS_LONG" type="xsd:boolean" minOccurs="0" />
           <xsd:element sql:field="BEST_MATCH" name="BEST_MATCH" type="xsd:boolean" 
                        minOccurs="0" />
           <xsd:element sql:field="IS_FIXEDLENGTH" name="IS_FIXEDLENGTH" type="xsd:boolean" 
                        minOccurs="0" />
         </xsd:sequence>
       </xsd:complexType>