---
title: "SQLGetDescField | Microsoft Docs"
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# SQLGetDescField
[!INCLUDE[SNAC_Deprecated](../../includes/snac-deprecated.md)]

  The [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] Native Client ODBC driver exposes driver-specific descriptor fields for the implementation row descriptor (IRD) only. Within the IRD, [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] descriptor fields are referenced through driver-specific column attributes. For information about a complete list of available driver-specific descriptor fields, see [SQLColAttribute](../../relational-databases/native-client-odbc-api/sqlcolattribute.md).  
  
 Descriptor fields that contain column identifier strings are often zero-length strings. All [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)]-specific descriptor field values are read-only.  
  
 Like attributes retrieved with SQLColAttribute, descriptor fields that report row-level attributes (such as SQL_CA_SS_COMPUTE_ID) are reported for all columns in the result set.  
  
## SQLGetDescField and Table-Valued Parameters  
 SQLGetDescField can be used to get values for extended attributes of table-valued parameters and table-valued parameter columns. For more information about table-valued parameters, see [Table-Valued Parameters (ODBC)](../../relational-databases/native-client-odbc-table-valued-parameters/table-valued-parameters-odbc.md).  
  
## SQLGetDescField Support for Enhanced Date and Time Features  
 For information about the descriptor fields available with the new date/time types, see [Parameter and Result Metadata](../../relational-databases/native-client-odbc-date-time/metadata-parameter-and-result.md).  
  
 For more information, see [Date and Time Improvements (ODBC)](../../relational-databases/native-client-odbc-date-time/date-and-time-improvements-odbc.md).  
  
 Beginning in [!INCLUDE[ssSQL11](../../includes/sssql11-md.md)], SQLGetDescField can return **SQL_C_SS_TIME2** (for **time** types) or **SQL_C_SS_TIMESTAMPOFFSET** (for **datetimeoffset**) instead of **SQL_C_BINARY**, if your application uses ODBC 3.8.  
  
## SQLGetDescField Support for Large CLR UDTs  
 **SQLGetDescField** supports large CLR user-defined types (UDTs). For more information, see [Large CLR User-Defined Types (ODBC)](../../relational-databases/native-client/odbc/large-clr-user-defined-types-odbc.md).  
  
## SQLGetDescField Support for Sparse Columns  
 SQLGetDescField can be used to query the new IRD field SQL_CA_SS_IS_COLUMN_SET to determine if a column is a **column_set** column.  
  
 For more information, see [Sparse Columns Support (ODBC)](../../relational-databases/native-client/odbc/sparse-columns-support-odbc.md).  
  
## Example  
  
```  
typedef struct tagCOMPUTEBYLIST  
    {  
    SQLSMALLINT nBys;  
    SQLSMALLINT aByList[1];  
    } COMPUTEBYLIST;  
typedef COMPUTEBYLIST* PCOMPUTEBYLIST;   
  
SQLHDESC    hIRD;   
SQLINTEGER  cbIRD;   
SQLINTEGER  nSet = 0;   
  
// . . .  
// Execute a statement that contains a COMPUTE clause,  
//  then get the descriptor handle of the IRD and  
//  get some IRD values.  
  
SQLGetStmtAttr(g_hStmt, SQL_ATTR_IMP_ROW_DESC,  
    (SQLPOINTER) &hIRD, sizeof(SQLHDESC), &cbIRD);  
  
// For statement-wide column attributes, any  
//  descriptor record will do. You know that 1 exists,  
//  so use it.  
SQLGetDescField(hIRD, 1, SQL_CA_SS_NUM_COMPUTES,  
    (SQLPOINTER) &nComputes, SQL_IS_INTEGER, &cbIRD);  
  
if (nSet == 0)  
    {  
    SQLINTEGER      nOrderID;  
  
    printf_s("Normal result set.\n");  
  
    for (nCol = 0; nCol < nCols; nCol++)  
        {  
        SQLGetDescField(hIRD, nCol+1,  
            SQL_CA_SS_COLUMN_ORDER,  
            (SQLPOINTER) &nOrderID, SQL_IS_INTEGER,  
            &cbIRD);  
  
        if (nOrderID != 0)  
            {  
            printf_s("Col in ORDER BY, pos: %ld",  
                nOrderID);  
            }  
            printf_s("\n");  
        }  
  
    printf_s("\n");  
    }  
else  
    {  
    PCOMPUTEBYLIST  pByList;  
    SQLSMALLINT     nBy;  
    SQLINTEGER      nColID;  
  
    printf_s("Computed result set number: %lu\n",  
        nSet);  
  
    SQLGetDescField(hIRD, 1, SQL_CA_SS_COMPUTE_BYLIST,  
        (SQLPOINTER) &pByList, SQL_IS_INTEGER,  
        &cbIRD);  
  
    if (pByList != NULL)  
        {  
        printf_s("Clause ordered by columns: ");  
        for (nBy = 0; nBy < pByList->nBys; )  
            {  
            printf_s("%u", pByList->aByList[nBy]);  
            nBy++;  
  
            if (nBy == pByList->nBys)  
                {  
                printf_s("\n");  
                }  
            else  
                {  
                printf_s(", ");  
                }  
            }  
        }  
    else  
        {  
        printf_s("Compute clause set not ordered.\n");  
        }  
  
    for (nCol = 0; nCol < nCols; nCol++)  
        {  
        SQLGetDescField(hIRD, nCol+1,  
            SQL_CA_SS_COLUMN_ID, (SQLPOINTER) &nColID,  
            SQL_IS_INTEGER, &cbIRD);  
        printf_s("ColumnID: %lu, nColID);  
        }  
    printf_s("\n");  
    }  
  
if (SQLMoreResults(g_hStmt) == SQL_SUCCESS)  
    {  
    // Determine the result set indicator.  
    SQLGetDescField(hIRD, 1, SQL_CA_SS_COMPUTE_ID,  
        (SQLPOINTER) &nSet, SQL_IS_INTEGER, &cbIRD);  
    }  
```  
  
## See Also  
 [SQLGetDescField Function](http://go.microsoft.com/fwlink/?LinkId=59351)   
 [ODBC API Implementation Details](../../relational-databases/native-client-odbc-api/odbc-api-implementation-details.md)