Calling Natively Compiled Stored Procedures from Data Access Applications

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance

This topic discusses guidance on calling natively compiled stored procedures from data access applications.

Guidance points

  • Cursors cannot iterate over a natively compiled stored procedure.

  • Calling natively compiled stored procedures from CLR modules, by using the context connection, is not supported.

SqlClient

  • For SqlClient, there is no distinction between prepared and direct execution. Execute stored procedures with SqlCommand with CommandType = CommandType.StoredProcedure.

  • SqlClient does not support prepared RPC procedure calls.

  • SqlClient does not support the retrieval of schema-only information (metadata discovery) about the result sets returned by a natively compiled stored procedure (CommandType.SchemaOnly).

Microsoft ODBC Driver for SQL Server (MSODBCSQL)

  • Versions of SQL Server Native Client prior to SQL Server 2012 (11.x) do not support the retrieval of schema-only information (metadata discovery) about the result sets returned by a natively compiled stored procedure.
  • Instead, use sp_describe_first_result_set (Transact-SQL).
  • This sample was originally written for the SQL Server Native Client (sqlncli.h) but has been updated to use the Microsoft ODBC Driver for SQL Server (MSODBCSQL). The SQL Server Native Client (often abbreviated SNAC) has been removed from SQL Server 2022 (16.x) and SQL Server Management Studio 19 (SSMS). The SQL Server Native Client (SQLNCLI or SQLNCLI11) and the legacy Microsoft OLE DB Provider for SQL Server (SQLOLEDB) are not recommended for new application development. Switch to the new Microsoft OLE DB Driver (MSOLEDBSQL) for SQL Server or the latest Microsoft ODBC Driver for SQL Server going forward. For SQLNCLI that ships as a component of SQL Server Database Engine (versions 2012 through 2019), see this Support Lifecycle exception.

ODBC

The following recommendations apply to calls of natively compiled stored procedure using the ODBC driver in SQL Server Native Client.

Call one time: The most efficient way to call a stored procedure once is to issue a direct RPC call using SQLExecDirect and ODBC CALL clauses. Do not use the Transact-SQL EXECUTE statement. If a stored procedure is called more than once, prepared execution is more efficient.

Call many times: The most efficient way to call a SQL Server stored procedure more than once is through prepared RPC procedure calls. Prepared RPC calls are performed as follows using the ODBC driver in SQL Server Native Client:

  1. Open a connection to the database.
  2. Bind the parameters by using SQLBindParameter.
  3. Prepare the procedure call by using SQLPrepare.
  4. Execute the stored procedure multiple times by using SQLExecute.

C code for ODBC

The following C code fragment shows prepared execution of a stored procedure to add line items to an order. SQLPrepare is called only once. And SQLExecute is called multiple times, once for each procedure execution.

// Bind parameters
// 1 - OrdNo
SQLRETURN returnCode = SQLBindParameter(
                     hstmt, 1, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, 10, 0,
                     &order.OrdNo, sizeof(SQLINTEGER), NULL);
if (returnCode != SQL_SUCCESS && returnCode != SQL_SUCCESS_WITH_INFO) {
   ODBCError(henv, hdbc, hstmt, NULL, true);
   exit(-1);
}

// 2, 3, 4 - ItemNo, ProdCode, Qty
...

// Prepare stored procedure
returnCode = SQLPrepare(hstmt, (SQLTCHAR *) _T("{call ItemInsert(?, ?, ?, ?)}"),
                        SQL_NTS);

for (unsigned int i = 0; i < order.ItemCount; i++) {
   ItemNo = order.ItemNo[i];
   ProdCode = order.ProdCode[i];
   Qty = order.Qty[i];

   // Execute stored procedure
   returnCode = SQLExecute(hstmt);
   if (returnCode != SQL_SUCCESS && returnCode != SQL_SUCCESS_WITH_INFO) {
      ODBCError(henv, hdbc, hstmt, NULL, true);
      exit(-1);
   }
}

Using ODBC to Execute a Natively Compiled Stored Procedure

This sample shows how to bind parameters and execute stored procedures using the SQL Server Native Client ODBC driver. The sample compiles to a console application that inserts a single order using direct execution, and inserts the order details using prepared execution.

To run this sample:

  1. Create a sample database with a memory-optimized data filegroup. For information on how to create a database with a memory-optimized data filegroup, see Creating a Memory-Optimized Table and a Natively Compiled Stored Procedure.

  2. Create an ODBC data source called PrepExecSample that points to the database. Use the SQL Server Native Client driver. You could also modify the sample and use the Microsoft ODBC Driver for SQL Server.

  3. Run the Transact-SQL script (below) on the sample database.

  4. Compile and run the sample.

  5. Verify successful execution of the program by querying the contents of the tables:

    SELECT * FROM dbo.Ord;
    
    SELECT * FROM dbo.Item;
    

Preliminary Transact-SQL

The following is the Transact-SQL code listing that creates the memory-optimized database objects.

IF EXISTS (SELECT * FROM SYS.OBJECTS WHERE OBJECT_ID=OBJECT_ID('dbo.OrderInsert'))
DROP PROCEDURE dbo.OrderInsert;  
GO
IF EXISTS (SELECT * FROM SYS.OBJECTS WHERE OBJECT_ID=OBJECT_ID('dbo.ItemInsert'))
DROP PROCEDURE dbo.ItemInsert;  
GO  
IF EXISTS (SELECT * FROM SYS.OBJECTS WHERE OBJECT_ID=OBJECT_ID('dbo.Ord'))
DROP TABLE dbo.Ord;  
GO  
IF EXISTS (SELECT * FROM SYS.OBJECTS WHERE OBJECT_ID=OBJECT_ID('dbo.Item'))
DROP TABLE dbo.Item;  
GO

CREATE TABLE dbo.Ord  
(  
   OrdNo INTEGER NOT NULL PRIMARY KEY NONCLUSTERED,  
   OrdDate DATETIME NOT NULL,   
   CustCode VARCHAR(5) NOT NULL)   
 WITH (MEMORY_OPTIMIZED=ON);  
GO  
  
CREATE TABLE dbo.Item  
(  
   OrdNo INTEGER NOT NULL,   
   ItemNo INTEGER NOT NULL,   
   ProdCode INTEGER NOT NULL,   
   Qty INTEGER NOT NULL,  
   CONSTRAINT PK_Item PRIMARY KEY NONCLUSTERED (OrdNo,ItemNo))  
   WITH (MEMORY_OPTIMIZED=ON);  
GO  
  
CREATE PROCEDURE dbo.OrderInsert(
    @OrdNo INTEGER, @CustCode VARCHAR(5))  
WITH NATIVE_COMPILATION, SCHEMABINDING, EXECUTE AS OWNER  
AS BEGIN ATOMIC WITH  
   (TRANSACTION ISOLATION LEVEL = SNAPSHOT, LANGUAGE = 'english')  
  
  DECLARE @OrdDate datetime = GETDATE();  
  INSERT INTO dbo.Ord (OrdNo, CustCode, OrdDate)
  VALUES (@OrdNo, @CustCode, @OrdDate);
END;  
GO  
  
CREATE PROCEDURE dbo.ItemInsert(
    @OrdNo INTEGER, @ItemNo INTEGER, @ProdCode INTEGER, @Qty INTEGER)
WITH NATIVE_COMPILATION, SCHEMABINDING, EXECUTE AS OWNER  
AS BEGIN ATOMIC WITH  
   (TRANSACTION ISOLATION LEVEL = SNAPSHOT, LANGUAGE = N'us_english')  
  
  INSERT INTO dbo.Item (OrdNo, ItemNo, ProdCode, Qty)
  VALUES (@OrdNo, @ItemNo, @ProdCode, @Qty)
END  
GO  

C code

The following is the C code listing.

// compile with: user32.lib odbc32.lib
#pragma once  
#define WIN32_LEAN_AND_MEAN  // Exclude rarely-used stuff from Windows headers.
#include <stdio.h>  
#include <stdlib.h>  
#include <tchar.h>  
#include <windows.h>  
#include "sql.h"  
#include "sqlext.h"  
#include "msodbcsql.h"  
  
// cardinality of order item related array variables
#define ITEM_ARRAY_SIZE 20  
  
// struct to pass order entry data  
typedef struct OrdEntry_struct {  
   SQLINTEGER OrdNo;  
   SQLTCHAR CustCode[6];  
   SQLUINTEGER ItemCount;  
   SQLINTEGER ItemNo[ITEM_ARRAY_SIZE];  
   SQLINTEGER ProdCode[ITEM_ARRAY_SIZE];  
   SQLINTEGER Qty[ITEM_ARRAY_SIZE];  
} OrdEntryData;  
  
SQLHANDLE henv, hdbc, hstmt;  
  
void ODBCError(
      SQLHANDLE henv, SQLHANDLE hdbc,
      SQLHANDLE hstmt, SQLHANDLE hdesc,
      bool ShowError)
{  
   SQLRETURN r = 0;  
   SQLTCHAR szSqlState[6] = {0};  
   SQLINTEGER fNativeError = 0;  
   SQLTCHAR szErrorMsg[256] = {0};  
   SQLSMALLINT cbErrorMsgMax = sizeof(szErrorMsg) - 1;
   SQLSMALLINT cbErrorMsg = 0;  
   TCHAR text[1024] = {0}, title[256] = {0};  
  
   if (hdesc != NULL)  
      r = SQLGetDiagRec(SQL_HANDLE_DESC, hdesc, 1, szSqlState,
              &fNativeError, szErrorMsg, cbErrorMsgMax, &cbErrorMsg);
   else {  
      if (hstmt != NULL)  
         r = SQLGetDiagRec(SQL_HANDLE_STMT, hstmt, 1, szSqlState,
                 &fNativeError, szErrorMsg, cbErrorMsgMax, &cbErrorMsg);
      else {  
         if (hdbc != NULL)  
            r = SQLGetDiagRec(SQL_HANDLE_DBC, hdbc, 1, szSqlState,
                    &fNativeError, szErrorMsg, cbErrorMsgMax, &cbErrorMsg);
         else  
            r = SQLGetDiagRec(SQL_HANDLE_ENV, henv, 1, szSqlState,
                    &fNativeError, szErrorMsg, cbErrorMsgMax, &cbErrorMsg);
      }  
   }  
  
   if (ShowError) {  
      _sntprintf_s(title, _countof(title), _TRUNCATE, _T("ODBC Error %i"),
                      fNativeError);  
      _sntprintf_s(text, _countof(text), _TRUNCATE, _T("[%s] - %s"),
                      szSqlState, szErrorMsg);  
  
      MessageBox(NULL, (LPCTSTR) text, (LPCTSTR) _T("ODBC Error"), MB_OK);
   }  
}  
  
void connect() {  
   SQLRETURN r;  
  
   r = SQLAllocHandle(SQL_HANDLE_ENV, NULL, &henv);  
  
   // This is an ODBC v3 application  
   r = SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION, (SQLPOINTER) SQL_OV_ODBC3, 0);
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, NULL, NULL, NULL, true);  
      exit(-1);  
   }  
  
   r = SQLAllocHandle(SQL_HANDLE_DBC, henv, &hdbc);  
  
   // Run in ANSI/implicit transaction mode  
   r = SQLSetConnectAttr(hdbc, SQL_ATTR_AUTOCOMMIT,
                          (SQLPOINTER) SQL_AUTOCOMMIT_OFF, SQL_IS_INTEGER);
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, NULL, NULL, NULL, true);  
      exit(-1);  
   }  
  
   TCHAR szConnStrIn[256] = _T("DSN=PrepExecSample");  
  
   r = SQLDriverConnect(hdbc, NULL, (SQLTCHAR *) szConnStrIn, SQL_NTS,
                          NULL, 0, NULL, SQL_DRIVER_NOPROMPT);
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, NULL, NULL, true);  
      exit(-1);  
   }  
}  
  
void setup_ODBC_basics() {  
   SQLRETURN r;  
  
   r = SQLAllocHandle(SQL_HANDLE_STMT, hdbc, &hstmt);  
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);  
      exit(-1);  
   }  
}  
  
void OrdEntry(OrdEntryData& order) {  
   // Simple order entry  
   SQLRETURN r;  
  
   SQLINTEGER ItemNo, ProdCode, Qty;  
  
   // Bind parameters for the Order  
   // 1 - OrdNo input  
   r = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER,
                          0, 0, &order.OrdNo, sizeof(SQLINTEGER), NULL);
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   // 2 - Custcode input  
   r = SQLBindParameter(hstmt, 2, SQL_PARAM_INPUT,SQL_C_TCHAR, SQL_VARCHAR, 5, 0,
                          &order.CustCode, sizeof(order.CustCode), NULL);
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   // Insert the order  
   r = SQLExecDirect(hstmt, (SQLTCHAR *) _T("{call OrderInsert(?, ?)}"),SQL_NTS);
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   // Flush results & reset hstmt  
   r = SQLMoreResults(hstmt);  
   if (r != SQL_NO_DATA) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   r = SQLFreeStmt(hstmt, SQL_RESET_PARAMS);  
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   // Bind parameters for the Items  
   // 1 - OrdNo   
   r = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, 10, 0,
                          &order.OrdNo, sizeof(SQLINTEGER), NULL);  
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   // 2 - ItemNo   
   r = SQLBindParameter(hstmt, 2, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, 10, 0,
                          &ItemNo, sizeof(SQLINTEGER), NULL);  
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   // 3 - ProdCode  
   r = SQLBindParameter(hstmt, 3, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, 10, 0,
                          &ProdCode, sizeof(SQLINTEGER), NULL);  
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   // 4 - Qty  
   r = SQLBindParameter(hstmt, 4, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, 10, 0,
                          &Qty, sizeof(SQLINTEGER), NULL);  
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   // Prepare to insert items one at a time  
   r = SQLPrepare(hstmt, (SQLTCHAR *) _T("{call ItemInsert(?, ?, ?, ?)}"),SQL_NTS);
  
   for (unsigned int i = 0; i < order.ItemCount; i++) {  
  ItemNo = order.ItemNo[i];  
      ProdCode = order.ProdCode[i];  
      Qty = order.Qty[i];  
      r = SQLExecute(hstmt);  
      if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
         ODBCError(henv, hdbc, hstmt, NULL, true);   
         exit(-1);  
      }  
   }  
  
   // Flush results & reset hstmt  
   r = SQLMoreResults(hstmt);  
   if (r != SQL_NO_DATA) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   r = SQLFreeStmt(hstmt, SQL_RESET_PARAMS);  
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
  
   // Commit the transaction  
   r = SQLEndTran(SQL_HANDLE_DBC, hdbc, SQL_COMMIT);  
   if (r != SQL_SUCCESS && r != SQL_SUCCESS_WITH_INFO) {  
      ODBCError(henv, hdbc, hstmt, NULL, true);   
      exit(-1);  
   }  
}  
  
void testOrderEntry() {  
  
   OrdEntryData order;  
  
   order.OrdNo = 1;  
   _tcscpy_s((TCHAR *) order.CustCode, _countof(order.CustCode), _T("CUST1"));
   order.ItemNo[0] = 1;  
   order.ProdCode[0] = 10;  
   order.Qty[0] = 1;  
   order.ItemNo[1] = 2;  
   order.ProdCode[1] = 20;  
   order.Qty[1] = 2;  
   order.ItemNo[2] = 3;  
   order.ProdCode[2] = 30;  
   order.Qty[2] = 3;  
   order.ItemNo[3] = 4;  
   order.ProdCode[3] = 40;  
   order.Qty[3] = 4;  
   order.ItemCount = 4;  
  
   OrdEntry(order);  
}  
int _tmain() {  
   connect();  
   setup_ODBC_basics();  
  
   testOrderEntry();  
}  

See Also

Natively Compiled Stored Procedures