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SSVARIANT Structure in SQL Server Native Client

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Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW)

The SSVARIANT structure, which is defined in sqlncli.h, corresponds to a DBTYPE_SQLVARIANT value in the SQL Server Native Client OLEDB provider.

SSVARIANT is a discriminating union. Depending on the value of the vt member, the consumer can determine which member to read. vt values correspond to SQL Server data types. Therefore, the SSVARIANT structure can hold any SQL Server type. For more information about the data structure for standard OLE DB types, see Type Indicators.

Remarks

When DataTypeCompat==80, several SSVARIANT subtypes become strings. For example, the following vt values will appear in SSVARIANT as VT_SS_WVARSTRING:

  • VT_SS_DATETIMEOFFSET

  • VT_SS_DATETIME2

  • VT_SS_TIME2

  • VT_SS_DATE

When DateTypeCompat == 0, these types will appear in their native form.

For more information about SSPROP_INIT_DATATYPECOMPATIBILITY, see Using Connection String Keywords with SQL Server Native Client.

The sqlncli.h file contains variant access macros that simplify dereferencing the member types in the SSVARIANT structure. An example is V_SS_DATETIMEOFFSET, which you can use as follows:

memcpy(&V_SS_DATETIMEOFFSET(pssVar).tsoDateTimeOffsetVal, pDTO, cbNative);  
V_SS_DATETIMEOFFSET(pssVar).bScale = bScale;

For the complete set of access macros for each member of the SSVARIANT structure, refer to the sqlncli.hi file.

The following table describes the members of the SSVARIANT structure:

Member OLE DB type indicator OLE DB C data type vt value Comments
vt SSVARTYPE Specifies the type of value contained in the SSVARIANT struct.
bTinyIntVal DBTYPE_UI1 BYTE VT_SS_UI1 Supports the tinyintSQL Server data type.
sShortIntVal DBTYPE_I2 SHORT VT_SS_I2 Supports the smallintSQL Server data type.
lIntVal DBTYPE_I4 LONG VT_SS_I4 Supports the intSQL Server data type.
llBigIntVal DBTYPE_I8 LARGE_INTEGER VT_SS_I8 Supports the bigintSQL Server data type.
fltRealVal DBTYPE_R4 float VT_SS_R4 Supports the realSQL Server data type.
dblFloatVal DBTYPE_R8 double VT_SS_R8 Supports the floatSQL Server data type.
cyMoneyVal DBTYPE_CY LARGE_INTEGER VT_SS_MONEY VT_SS_SMALLMONEY Supports the money and smallmoneySQL Server data types.
fBitVal DBTYPE_BOOL VARIANT_BOOL VT_SS_BIT Supports the bitSQL Server data type.
rgbGuidVal DBTYPE_GUID GUID VT_SS_GUID Supports the uniqueidentifierSQL Server data type.
numNumericVal DBTYPE_NUMERIC DB_NUMERIC VT_SS_NUMERIC Supports the numericSQL Server data type.
dDateVal DBTYPE_DATE DBDATE VT_SS_DATE Supports the dateSQL Server data type.
tsDateTimeVal DBTYPE_DBTIMESTAMP DBTIMESTAMP VT_SS_SMALLDATETIME VT_SS_DATETIME VT_SS_DATETIME2 Supports the smalldatetime, datetime, and datetime2SQL Server data types.
Time2Val DBTYPE_DBTIME2 DBTIME2 VT_SS_TIME2 Supports the timeSQL Server data type.

Includes the following members:

tTime2Val (DBTIME2)

bScale (BYTE) Specifies the scale for tTime2Val value.
DateTimeVal DBTYPE_DBTIMESTAMP DBTIMESTAMP VT_SS_DATETIME2 Supports the datetime2SQL Server data type.

Includes the following members:

tsDataTimeVal (DBTIMESTAMP)

bScale (BYTE) Specifies the scale for tsDataTimeVal value.
DateTimeOffsetVal DBTYPE_DBTIMESTAMPOFSET DBTIMESTAMPOFFSET VT_SS_DATETIMEOFFSET Supports the datetimeoffsetSQL Server data type.

Includes the following members:

tsoDateTimeOffsetVal (DBTIMESTAMPOFFSET)

bScale (BYTE) Specifies the scale for tsoDateTimeOffsetVal value.
NCharVal No corresponding OLE DB type indicator. struct _NCharVal VT_SS_WVARSTRING,

VT_SS_WSTRING		 Supports the nchar and nvarcharSQL Server data types.

Includes the following members:

sActualLength (SHORT) Specifies the actual length for the string to which pwchNCharVal points. Does not include terminating zero.

sMaxLength (SHORT) Specifies the maximum length for the string to which pwchNCharVal points.

pwchNCharVal (WCHAR *) Pointer to the string.

Unused members: rgbReserved, dwReserved, and pwchReserved.
CharVal No corresponding OLE DB type indicator. struct _CharVal VT_SS_STRING,

VT_SS_VARSTRING		 Supports the char and varcharSQL Server data types.

Includes the following members:

sActualLength (SHORT) Specifies the actual length for the string to which pchCharVal points. Does not include terminating zero.

sMaxLength (SHORT) Specifies the maximum length for the string to which pchCharVal points.

pchCharVal (CHAR *) Pointer to the string.

Unused members:

rgbReserved, dwReserved, and pwchReserved.
BinaryVal No corresponding OLE DB type indicator. struct _BinaryVal VT_SS_VARBINARY,

VT_SS_BINARY		 Supports the binary and varbinarySQL Server data types.

Includes the following members:

sActualLength (SHORT) Specifies the actual length for the data to which prgbBinaryVal points.

sMaxLength (SHORT) Specifies the maximum length for the data to which prgbBinaryVal points.

prgbBinaryVal (BYTE *) Pointer to the binary data.

Unused member: dwReserved.
UnknownType UNUSED UNUSED UNUSED UNUSED
BLOBType UNUSED UNUSED UNUSED UNUSED

See Also

Data Types (OLE DB)