#[repr(u16)]
pub enum Desc {
Show 43 variants
Count,
Type,
Length,
OctetLengthPtr,
Precision,
Scale,
DatetimeIntervalCode,
Nullable,
IndicatorPtr,
DataPtr,
Name,
Unnamed,
OctetLength,
AllocType,
ArraySize,
ArrayStatusPtr,
AutoUniqueValue,
BaseColumnName,
BaseTableName,
BindOffsetPtr,
BindType,
CaseSensitive,
CatalogName,
ConciseType,
DatetimeIntervalPrecision,
DisplaySize,
FixedPrecScale,
Label,
LiteralPrefix,
LiteralSuffix,
LocalTypeName,
MaximumScale,
MinimumScale,
NumPrecRadix,
ParameterType,
RowsProcessedPtr,
RowVer,
SchemaName,
Searchable,
TypeName,
TableName,
Unsigned,
Updatable,
}Expand description
Used in SQLColAttributeW.
Variants§
Count
SQL_DESC_COUNT. Returned in NumericAttributePtr. The number of columns available in the
result set. This returns 0 if there are no columns in the result set. The value in the
column_number argument is ignored.
Type
SQL_DESC_TYPE. Retruned in NumericAttributePtr. A numeric value that specifies the SQL
data type. When ColumnNumber is equal to 0, SQL_BINARY is returned for variable-length
bookmarks and SQL_INTEGER is returned for fixed-length bookmarks. For the datetime and
interval data types, this field returns the verbose data type: SQL_DATETIME or SQL_INTERVAL.
Note: To work against ODBC 2.x drivers, use SQL_DESC_CONCISE_TYPE instead.
Length
SQL_DESC_LENGTH. Returned in NumericAttributePtr. A numeric value that is either the
maximum or actual character length of a character string or binary data type. It is the
maximum character length for a fixed-length data type, or the actual character length for a
variable-length data type. Its value always excludes the null-termination byte that ends the
character string.
OctetLengthPtr
SQL_DESC_OCTET_LENGTH_PTR.
Precision
SQL_DESC_PRECISION. Returned in NumericAttributePtr. A numeric value that for a numeric
data type denotes the applicable precision. For data types SQL_TYPE_TIME,
SQL_TYPE_TIMESTAMP, and all the interval data types that represent a time interval, its
value is the applicable precision of the fractional seconds component.
Scale
SQL_DESC_SCALE. Returned in NumericAttributePtr. A numeric value that is the applicable
scale for a numeric data type. For DECIMAL and NUMERIC data types, this is the defined
scale. It is undefined for all other data types.
DatetimeIntervalCode
SQL_DESC_DATETIME_INTERVAL_CODE.
Nullable
SQL_DESC_NULLABLE. Returned in NumericAttributePtr. SQL_ NULLABLE if the column can
have NULL values; SQL_NO_NULLS if the column does not have NULL values; or
SQL_NULLABLE_UNKNOWN if it is not known whether the column accepts NULL values.
IndicatorPtr
SQL_DESC_INDICATOR_PTR
DataPtr
SQL_DESC_DATA_PTR.
Name
SQL_DESC_NAME. Returned in CharacterAttributePtr. The column alias, if it applies. If
the column alias does not apply, the column name is returned. In either case,
SQL_DESC_UNNAMED is set to SQL_NAMED. If there is no column name or a column alias, an empty
string is returned and SQL_DESC_UNNAMED is set to SQL_UNNAMED.
Unnamed
SQL_DESC_UNNAMED. Returned in NumericAttributePtr. SQL_NAMED or SQL_UNNAMED. If the
SQL_DESC_NAME field of the IRD contains a column alias or a column name, SQL_NAMED is
returned. If there is no column name or column alias, SQL_UNNAMED is returned.
OctetLength
SQL_DESC_OCTET_LENGTH. Returned in NumericAttributePtr. The length, in bytes, of a
character string or binary data type. For fixed-length character or binary types, this is
the actual length in bytes. For variable-length character or binary types, this is the
maximum length in bytes. This value does not include the null terminator.
AllocType
SQL_DESC_ALLOC_TYPE.
ArraySize
SQL_DESC_ARRAY_SIZE
ArrayStatusPtr
SQL_DESC_ARRAY_STATUS_PTR
AutoUniqueValue
SQL_DESC_AUTO_UNIQUE_VALUE. Returned in NumericAttributePtr. true if the column is an
autoincrementing column. false if the column is not an autoincrementing column or is not
numeric. This field is valid for numeric data type columns only. An application can insert
values into a row containing an autoincrement column, but typically cannot update values in
the column. When an insert is made into an autoincrement column, a unique value is inserted
into the column at insert time. The increment is not defined, but is data source-specific.
An application should not assume that an autoincrement column starts at any particular point
or increments by any particular value.
BaseColumnName
SQL_DESC_BASE_COLUMN_NAME. Returned in CharacterAttributePtr. The base column name for
the result set column. If a base column name does not exist (as in the case of columns that
are expressions), then this variable contains an empty string.
BaseTableName
SQL_DESC_BASE_TABLE_NAME. Returned in CharacterAttributePtr. The name of the base table
that contains the column. If the base table name cannot be defined or is not applicable,
then this variable contains an empty string.
BindOffsetPtr
SQL_DESC_BIND_OFFSET_PTR.
BindType
SQL_DESC_BIND_TYPE.
CaseSensitive
SQL_DESC_CASE_SENSITIVE. Returned in NumericAttributePtr. true if the column is
treated as case-sensitive for collations and comparisons. false if the column is not
treated as case-sensitive for collations and comparisons or is noncharacter.
CatalogName
SQL_DESC_CATALOG_NAME. Returned in CharacterAttributePtr. The catalog of the table that
contains the column. The returned value is implementation-defined if the column is an
expression or if the column is part of a view. If the data source does not support catalogs
or the catalog name cannot be determined, an empty string is returned. This VARCHAR record
field is not limited to 128 characters.
ConciseType
SQL_DESC_CONCISE_TYPE. Returned in NumericAttributePtr. The concise data type. For the
datetime and interval data types, this field returns the concise data type; for example,
SQL_TYPE_TIME or SQL_INTERVAL_YEAR.
DatetimeIntervalPrecision
SQL_DESC_DATETIME_INTERVAL_PRECISION
DisplaySize
SQL_DESC_DISPLAY_SIZE. Returned in NumericAttributePtr. Maximum number of characters
required to display data from the column.
FixedPrecScale
SQL_DESC_FIXED_PREC_SCALE. Returned in NumericAttributePtr. true if the column has a
fixed precision and nonzero scale that are data source-specific. false if the column does
not have a fixed precision and nonzero scale that are data source-specific.
Label
SQL_DESC_LABEL. Returned in CharacterAttributePtr. The column label or title. For
example, a column named EmpName might be labeled Employee Name or might be labeled with an
alias. If a column does not have a label, the column name is returned. If the column is
unlabeled and unnamed, an empty string is returned.
LiteralPrefix
SQL_DESC_LITERAL_PREFIX. Returned in CharacterAttributePtr. This VARCHAR(128) record
field contains the character or characters that the driver recognizes as a prefix for a
literal of this data type. This field contains an empty string for a data type for which a
literal prefix is not applicable.
LiteralSuffix
SQL_DESC_LITERAL_SUFFIX. Returned in CharacterAttributePtr. This VARCHAR(128) record
field contains the character or characters that the driver recognizes as a suffix for a
literal of this data type. This field contains an empty string for a data type for which a
literal suffix is not applicable.
LocalTypeName
SQL_DESC_LOCAL_TYPE_NAME. Returned in CharacterAttributePtr. This VARCHAR(128) record
field contains any localized (native language) name for the data type that may be different
from the regular name of the data type. If there is no localized name, then an empty string
is returned. This field is for display purposes only. The character set of the string is
locale-dependent and is typically the default character set of the server.
MaximumScale
SQL_DESC_MAXIMUM_SCALE.
MinimumScale
SQL_DESC_MINIMUM_SCALE.
NumPrecRadix
SQL_DESC_NUM_PREC_RADIX. Returned in NumericAttributePtr. If the data type in the
SQL_DESC_TYPE field is an approximate numeric data type, this SQLINTEGER field contains a
value of 2 because the SQL_DESC_PRECISION field contains the number of bits. If the data
type in the SQL_DESC_TYPE field is an exact numeric data type, this field contains a value
of 10 because the SQL_DESC_PRECISION field contains the number of decimal digits. This field
is set to 0 for all non-numeric data types.
ParameterType
SQL_DESC_PARAMETER_TYPE.
RowsProcessedPtr
SQL_DESC_ROWS_PROCESSED_PTR.
RowVer
SQL_DESC_ROWVER.
SchemaName
SQL_DESC_SCHEMA_NAME. Returned in CharacterAttributePtr. The schema of the table that
contains the column. The returned value is implementation-defined if the column is an
expression or if the column is part of a view. If the data source does not support schemas
or the schema name cannot be determined, an empty string is returned. This VARCHAR record
field is not limited to 128 characters.
Searchable
SQL_DESC_SEARCHABLE. Returned in NumericAttributePtr. SQL_PRED_NONE if the column
cannot be used in a WHERE clause. SQL_PRED_CHAR if the column can be used in a WHERE
clause but only with the LIKE predicate. SQL_PRED_BASIC if the column can be used in a
WHERE clause with all the comparison operators except LIKE. SQL_PRED_SEARCHABLE if the
column can be used in a WHERE clause with any comparison operator. Columns of type
SQL_LONGVARCHAR and SQL_LONGVARBINARY usually return SQL_PRED_CHAR.
TypeName
SQL_DESC_TYPE_NAME. Returned in CharacterAttributePtr. Data source-dependent data type
name; for example, “CHAR”, “VARCHAR”, “MONEY”, “LONG VARBINARY”, or “CHAR ( ) FOR BIT DATA”.
If the type is unknown, an empty string is returned.
TableName
SQL_DESC_TABLE_NAME. Returned in CharacterAttributePtr. The name of the table that
contains the column. The returned value is implementation-defined if the column is an
expression or if the column is part of a view. If the table name can not be determined an
empty string is returned.
Unsigned
SQL_DESC_UNSIGNED. Returned in NumericAttributePtr. true if the column is unsigned (or
not numeric). false if the column is signed.
Updatable
SQL_DESC_UPDATABLE. Returned in NumericAttributePtr. Column is described by the values
for the defined constants: SQL_ATTR_READONLY, SQL_ATTR_WRITE,
SQL_ATTR_READWRITE_UNKNOWN.
Updatable Describes the updatability of the column in the result set, not the column in
the base table. The updatability of the base column on which the result set column is based
may be different from the value in this field. Whether a column is updatable can be based on
the data type, user privileges, and the definition of the result set itself. If it is
unclear whether a column is updatable, SQL_ATTR_READWRITE_UNKNOWN should be returned.