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bcp_exec

  • Άρθρο

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

Executes a complete bulk copy of data between a database table and a user file.

Syntax

  
RETCODE bcp_exec (  
        HDBC hdbc,  
        LPDBINT pnRowsProcessed);

Arguments

hdbc
Is the bulk copy-enabled ODBC connection handle.

pnRowsProcessed
Is a pointer to a DBINT. The bcp_exec function fills this DBINT with the number of rows successfully copied. If pnRowsProcessed is NULL, it is ignored by bcp_exec.

Returns

SUCCEED, SUCCEED_ASYNC, or FAIL. The bcp_exec function returns SUCCEED if all rows are copied. bcp_exec returns SUCCEED_ASYNC if an asynchronous bulk copy operation is still outstanding. bcp_exec returns FAIL if a complete failure occurs, or if the number of rows generating errors reaches the value specified for BCPMAXERRS using bcp_control. BCPMAXERRS defaults to 10. The BCPMAXERRS option affects only the syntax errors detected by the provider while reading the rows from the data file (and not the rows sent to the server). Server aborts the batch when it detects an error with a row. Check the pnRowsProcessed parameter for the number of rows successfully copied.

Remarks

This function copies data from a user file to a database table or vice versa, depending on the value of the eDirection parameter in bcp_init.

Before calling bcp_exec, call bcp_init with a valid user file name. Failure to do so results in an error.

bcp_exec is the only bulk copy function that is likely to be outstanding for any length of time. It is therefore the only bulk copy function that supports asynchronous mode. To set asynchronous mode, use SQLSetConnectAttr to set SQL_ATTR_ASYNC_ENABLE to SQL_ASYNC_ENABLE_ON before calling bcp_exec. To test for completion, call bcp_exec with the same parameters. If the bulk copy has not yet completed, bcp_exec returns SUCCEED_ASYNC. It also returns in pnRowsProcessed a status count of the number of rows that have been sent to the server. Rows sent to the server are not committed until the end of a batch has been reached.

For information about a breaking change in bulk-copying beginning in SQL Server 2005 (9.x), see Performing Bulk Copy Operations (ODBC).

Example

The following example shows how to use bcp_exec:

// Variables like henv not specified.  
HDBC      hdbc;  
DBINT      nRowsProcessed;  
  
// Application initiation, get an ODBC environment handle, allocate the  
// hdbc, and so on.  
...   
  
// Enable bulk copy prior to connecting on allocated hdbc.  
SQLSetConnectAttr(hdbc, SQL_COPT_SS_BCP, (SQLPOINTER) SQL_BCP_ON,  
   SQL_IS_INTEGER);  
  
// Connect to the data source, return on error.  
if (!SQL_SUCCEEDED(SQLConnect(hdbc, _T("myDSN"), SQL_NTS,  
   _T("myUser"), SQL_NTS, _T("myPwd"), SQL_NTS)))  
   {  
   // Raise error and return.  
   return;  
   }  
  
// Initialize bulk copy.   
if (bcp_init(hdbc, _T("pubs..authors"), _T("authors.sav"), NULL, DB_OUT)  
   == FAIL)  
   {  
   // Raise error and return.  
   return;  
   }  
  
// Now, execute the bulk copy.   
if (bcp_exec(hdbc, &nRowsProcessed) == FAIL)  
   {  
   if (nRowsProcessed == -1)  
      {  
      printf_s("No rows processed on bulk copy execution.\n");  
      }  
   else  
      {  
      printf_s("Incomplete bulk copy.   Only %ld row%s copied.\n",  
         nRowsProcessed, (nRowsProcessed == 1) ? "": "s");  
      }  
   return;  
   }  
  
printf_s("%ld rows processed.\n", nRowsProcessed);  
  
// Carry on.

See Also

Bulk Copy Functions