Using isc_dsql_prepare() and isc_dsql_execute()

Go Up to Method 1: Non-query Statements Without Parameters

To execute a statement string several times, use isc_dsql_allocate_statement(), isc_dsql_prepare(), and isc_dsql_execute():

1. Elicit a statement string from the user or create one that contains the SQL statement to be processed. For example, the following statement creates a SQL statement string:

   char *str = "UPDATE DEPARTMENT SET BUDGET = BUDGET * 1.05";
   

2. Declare and initialize a SQL statement handle, then allocate it with isc_dsql_allocate_statement():

   isc_stmt_handle stmt; /* Declare a statement handle. */
   stmt = NULL; /* Set handle to NULL before allocation. */
   . . .
   isc_dsql_allocate_statement(status_vector, &db1, &stmt);
   

3. Parse the statement string with isc_dsql_prepare(). This sets the statement handle (stmt) to refer to the parsed format. The statement handle is used in subsequent calls to isc_dsql_execute():

   isc_dsql_prepare(status_vector, &trans, &stmt, 0, str, 1, NULL);
   

   isc_dsql_prepare() also accepts string literals. For example,

   isc_dsql_prepare(status_vector, &trans, &stmt, 0,
   "UPDATE DEPARTMENT SET BUDGET = BUDGET * 1.05", 1, NULL);
   

4. Execute the named statement string using isc_dsql_execute(). For example, the following statement executes a statement string named stmt:

   isc_dsql_execute(status_vector, &trans, &stmt, 1, NULL);
   

   Once a statement string is prepared, it can be executed as many times as required in an application.