MetaData Class

A MetaData object can be used to describe the types and properties of the columns in a ResultSet or the existing schema objects in the database. It also provides information about the database as a whole.

Listing of the parameter types for objects:

• PTYPE_TABLE
• PTYPE_VIEW
• PTYPE_PROC
• PTYPE_FUNC
• PTYPE_PKG
• PTYPE_TYPE
• PTYPE_TYPE_ATTR
• PTYPE_TYPE_COLL
• PTYPE_TYPE_METHOD
• PTYPE_SYN
• PTYPE_SEQ
• PTYPE_COL
• PTYPE_ARG
• PTYPE_TYPE_ARG
• PTYPE_TYPE_RESULT
• PTYPE_SCHEMA
• PTYPE_DATABASE
• PTYPE_UNK

Listing of attribute values:

• DURATION_SESSION
• DURATION_TRANS
• DURATION_NULL
• TYPEENCAP_PRIVATE
• TYPEENCAP_PUBLIC
• TYPEPARAM_IN
• TYPEPARAM_OUT
• TYPEPARAM_INOUT
• CURSOR_OPEN
• CURSOR_CLOSED
• CL_START
• CL_END
• SP_SUPPORTED
• SP_UNSUPPORTED
• NW_SUPPORTED
• NW_UNSUPPORTED
• AC_DDL
• NO_AC_DDL
• LOCK_IMMEDIATE
• LOCK_DELAYED

These are returned on executing a get method passing some attribute for which these are the results.

To..., use the syntax:

MetaData(const MetaData &omd);

omd

The source metadata object to be copied from.

Summary of MetaData Methods

Table 8-13 MetaData Methods  

Method	Summary
getAttributeCount()	Gets the count of the attribute as a MetaData object
getAttributeId()	Gets the ID of the specified attribute
getAttributeType()	Gets the type of the specified attribute.
getBoolean()	Gets the value of the attribute as a C++ boolean.
getInt()	Gets the value of the attribute as a C++ int.
getMetaData()	Gets the value of the attribute as a MetaData object
getNumber()	Returns the specified attribute as a Number object.
getRef()	Gets the value of the attribute as a Ref<T>.
getString()	Gets the value of the attribute as a string.
getTimeStamp()	Gets the value of the attribute as a Timestamp object
getUInt()	Gets the value of the attribute as a C++ unsigned int.
getVector()	Gets the value of the attribute as an C++ vector.
operator=()	Assigns one metadata object to another.

getAttributeCount()

This method returns the number of attributes related to the metadata object.

Syntax

unsigned int getAttributeCount() const;

getAttributeId()

This method returns the attribute ID (ATTR_NUM_COLS, . . . ) of the attribute represented by the attribute number specified.

Syntax

AttrId getAttributeId(unsigned int attributenum) const;

Parameters

attributenum

The number of the attribute for which the attribute ID is to be returned.

getAttributeType()

This method returns the attribute type (NUMBER, INT, . . . ) of the attribute represented by attribute number specified.

Syntax

Type getAttributeType(unsigned int attributenum) const;

Parameters

attributenum

The number of the attribute for which the attribute type is to be returned.

getBoolean()

This method returns the value of the attribute as a C++ boolean. If the value is a SQL null, the result is false.

Syntax

bool getBoolean(MetaData::AttrId attrid) const;

Parameters

attrid

The attribute ID.

getInt()

This method returns the value of the attribute as a C++ int. If the value is SQL null, the result is 0.

Syntax

int getInt(MetaData::AttrId attrid) const;

Parameters

attrid

The attribute ID .

getMetaData()

This method returns a MetaData instance holding the attribute value. A metadata attribute value can be retrieved as a MetaData instance. This method can only be called on attributes of the metadata type.

Syntax

MetaData getMetaData(MetaData::AttrId attrid) const;

Parameters

attrid

The attribute ID.

getNumber()

This method returns the value of the attribute as a Number object. If the value is a SQL null, the result is null.

Syntax

Number getNumber(MetaData::AttrId attrid) const;

Parameters

attrid

The attribute ID.

getRef()

This method returns the value of the attribute as a RefAny. If the value is SQL null, the result is null.

Syntax

RefAny getRef(MetaData::AttrId attrid) const;

Parameters

attrid

The attribute ID.

getString()

This method returns the value of the attribute as a string. If the value is SQL null, the result is null.

Syntax

string getString(MetaData::AttrId attrid) const;

Parameters

attrid

The attribute ID.

getTimeStamp()

This method returns the value of the attribute as a Timestamp object. If the value is a SQL null, the result is null.

Syntax

Timestamp getTimestamp(MetaData::AttrId attrid) const;

Parameters

attrid

The attribute ID.

getUInt()

This method returns the value of the attribute as a C++ unsigned int. If the value is a SQL null, the result is 0.

Syntax

unsigned int getUInt(MetaData::AttrId attrid) const;

Parameters

attrid

The attribute ID.

getVector()

This method returns a C++ vector containing the attribute value. A collection attribute value can be retrieved as a C++ vector instance. This method can only be called on attributes of a list type.

Syntax

vector<MetaData> getVector(MetaData::AttrId attrid) const;

Parameters

attrid

The attribute ID.

operator=()

This method assigns one MetaData object to another. This increments the reference count of the MetaData object that is assigned.

Syntax

void operator=(const MetaData &omd);

Parameters

omd

MetaData object to be assigned.