Executing an SQL UPDATE request

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4D v16

The method in the example below executes an SQL UPDATE request to update records that were added previously to the Oracle "emp" table. In this method, we update 3 records that were added by the INSERT request. We are only modifying the names (ename column).

Note that here we have done a bind (association of a 4D variable with an Oracle column) by name. In the previous INSERT request, we did the bind by position.

Example

Source code for OCI_UPDATE project method:

 C_TEXT($sql_request) //label of SQL request

 

 C_LONGINT($status) //return code of OCI commands

 C_LONGINT($errhp) //error handle

 C_LONGINT($stmthp) //request handle

 C_LONGINT($bind) //bind handle

 

 C_POINTER(pnull_ind1;pnull_ind2;pnull_ind3) //indicator variables (see the OCI_SELECT method)

 

 C_LONGINT($nb_emp) //number of employees to update

 

  //declaration of data to modify

 ARRAY LONGINT(tlu_empno;3) //empno column

 ARRAY TEXT(tau_ename;3) //ename column

 

  //search criteria in SQL request for the update

 tlu_empno{1}:=1111

 tlu_empno{2}:=2222

 tlu_empno{3}:=3333

  //modified data

 tau_ename{1}:="JJ"

 tau_ename{2}:="CC"

 tau_ename{3}:="MM"

 

  //update of employee names in the Oracle "emp" table whose numbers are 1111, 2222, and 3333

  //reminder: it is the data that was inserted that is modified

 $sql_request:="UPDATE emp SET ename=:the_names WHERE empno=:the_numbers"

 

  //allocation of request handle

 $status:=OCIHandleAlloc(envhp;$stmthp;OCI_HTYPE_STMT)

 

  //allocation of error handle

 $status:=OCIHandleAlloc(envhp;$errhp;OCI_HTYPE_ERROR)

 

  //assignment SQL request label to request handle

 $status:=OCIStmtPrepare($stmthp;$errhp;$sql_request;OCI_DEFAULT)

 

  //we do a bind by name. On the INSERT, we did it by position

 $status:=OCIBindByName($stmthp;$bind;$errhp;":the_names";->

 tau_ename;SQLT_STR;pnull_ind1;pnull_ind2;pnull_ind3;OCI_DEFAULT;BIND_IN)

 $status:=OCIBindByName($stmthp;$bind;$errhp;":the_numbers";->

 tlu_empno;SQLT_INT;pnull_ind1;pnull_ind2;pnull_ind3;OCI_DEFAULT;BIND_IN)

 

  //execution of SQL request

 $nb_emp:=3

 $status:=OCIStmtExecute(svchp;$stmthp;$errhp;$nb_emp;0;0;0;OCI_DEFAULT)

 

  //confirmation of modification by immediate validation of the transaction

  //otherwise, the update is done when the session is closed

 status:=OCITransCommit(svchp;$errhp;0)

 

  //release of request handle

 $status:=OCIHandleFree($stmthp)

 

  //release of error handle

 $status:=OCIHandleFree($errhp)