nanodbc::implementation_row_descriptor Class Reference

Provides access to metadata in the Implementation Row Descriptor (IRD) implicitly allocated for a prepared or executed statement. More...

#include <nanodbc.h>

Public Member Functions
	implementation_row_descriptor (result const &result)
	Initializes IRD access from statement of executed result set.
	implementation_row_descriptor (statement const &statement)
	Initializes IRD access from prepared or executed statement.
auto	alloc_type () const -> short
	Value of the header field SQL_DESC_ALLOC_AUTO.
auto	count () const noexcept -> short
	Value of the header field SQL_DESC_COUNT.
auto	auto_unique_value (short record) const -> bool
	Boolean based on value of the SQL_DESC_AUTO_UNIQUE_VALUE field.
auto	base_column_name (short record) const -> string
	Value of the SQL_DESC_BASE_COLUMN_NAME field.
auto	base_table_name (short record) const -> string
	Value of the SQL_DESC_BASE_TABLE_NAME field.
auto	case_sensitive (short record) const -> bool
	Boolean based on value of the SQL_DESC_CASE_SENSITIVE field.
auto	catalog_name (short record) const -> string
	Value of the SQL_DESC_CATALOG_NAME field.
auto	concise_type (short record) const -> short
	Value of the SQL_DESC_CONCISE_TYPE field.
auto	display_size (short record) const -> std::int64_t
	Value of the SQL_DESC_DISPLAY_SIZE field.
auto	fixed_prec_scale (short record) const -> short
	Value of the SQL_DESC_FIXED_PREC_SCALE field.
auto	label (short record) const -> string
	Value of the SQL_DESC_LABEL field.
auto	length (short record) const -> std::uint64_t
	Value of the SQL_DESC_LENGTH field.
auto	local_type_name (short record) const -> string
	Value of the SQL_DESC_LOCAL_TYPE_NAME field.
auto	name (short record) const -> string
	Value of the SQL_DESC_NAME field.
auto	nullable (short record) const -> short
	Value of the SQL_DESC_NULLABLE field.
auto	num_prec_radix (short record) const -> short
	Value of the SQL_DESC_NUM_PREC_RADIX field.
auto	octet_length (short record) const -> std::int64_t
	Value of the SQL_DESC_OCTET_LENGTH field.
auto	precision (short record) const -> short
	Value of the SQL_DESC_PRECISION field.
auto	rowver (short record) const -> short
	Value of the SQL_DESC_ROWVER field.
auto	scale (short record) const -> short
	Value of the SQL_DESC_SCALE field.
auto	schema_name (short record) const -> string
	Value of the SQL_DESC_SCHEMA_NAME field.
auto	searchable (short record) const -> short
	Value of the SQL_DESC_SEARCHABLE field.
auto	table_name (short record) const -> string
	Value of the SQL_DESC_TABLE_NAME field.
auto	type (short record) const -> short
	Value of the SQL_DESC_TYPE field.
auto	type_name (short record) const -> string
	Value of the SQL_DESC_TYPE_NAME field.
auto	unnamed (short record) const -> bool
	Boolean based on value of the SQL_DESC_UNNAMED field.
auto	unsigned_ (short record) const -> bool
	Boolean based on value of the SQL_DESC_UNSIGNED field.
auto	updatable (short record) const -> short
	Value of the SQL_DESC_UPDATABLE field.

Detailed Description

Provides access to metadata in the Implementation Row Descriptor (IRD) implicitly allocated for a prepared or executed statement.

The IRD contains information about the columns in a result set, such as their SQL data types, lengths, and nullability.

Constructor & Destructor Documentation

implementation_row_descriptor()

nanodbc::implementation_row_descriptor::implementation_row_descriptor

(

statement const &

statement

)

Initializes IRD access from prepared or executed statement.

For performance reasons, an application should ensure the statement is executed before accessing any of the IRD fields. Accessing (i.e. calls to SQLGetDescRec) the descriptor fields of prepared only statement causes a roundtrip to SQL Server.

Note

Some fields of the descriptor are available on result set retrieved from statements that generate server cursors or on executed SQL Server SELECT statements containing a FOR BROWSE clause (database-specific).

Member Function Documentation

nullable()

auto nanodbc::implementation_row_descriptor::nullable

(

short

record

)

const -> short

Value of the SQL_DESC_NULLABLE field.

Returns

Possible return values are SQL_NULLABLE, SQL_NO_NULLS or SQL_NULLABLE_UNKNOWN.

searchable()

auto nanodbc::implementation_row_descriptor::searchable

(

short

record

)

const -> short

Value of the SQL_DESC_SEARCHABLE field.

Returns

Possible return values are SQL_PRED_NONE, SQL_PRED_CHAR, SQL_PRED_BASIC or SQL_PRED_SEARCHABLE.

updatable()

auto nanodbc::implementation_row_descriptor::updatable

(

short

record

)

const -> short

Value of the SQL_DESC_UPDATABLE field.

Returns

Possible return values are SQL_ATTR_READ_ONLY, SQL_ATTR_WRITE or SQL_ATTR_READWRITE_UNKNOWN.

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The documentation for this class was generated from the following file:

• /home/runner/work/nanodbc/nanodbc/nanodbc/nanodbc.h