This section describes how to construct and execute a SQL statement, using bound parameters to set values for statement parameters at runtime.
Allocate a handle for the statement using SQLAllocHandle.
For example, the following statement allocates a handle of type
SQL_HANDLE_STMT with name
stmt, on a connection with handle
SQLAllocHandle( SQL_HANDLE_STMT, dbc, &stmt );
Bind parameters for the statement using SQLBindParameter.
For example, the following lines declare variables to hold the values for the department ID, department name, and manager ID, as well as for the statement string itself. They then bind parameters to the first, second, and third parameters of a statement executed using the stmt statement handle.
#defined DEPT_NAME_LEN 40 SQLINTEGER cbDeptID = 0, cbDeptName = SQL_NTS, cbManagerID = 0; SQLCHAR deptName[ DEPT_NAME_LEN + 1 ]; SQLSMALLINT deptID, managerID; SQLCHAR insertstmt[ STMT_LEN ] = "INSERT INTO Departments " "( DepartmentID, DepartmentName, DepartmentHeadID )" "VALUES (?, ?, ?)"; SQLBindParameter( stmt, 1, SQL_PARAM_INPUT, SQL_C_SSHORT, SQL_INTEGER, 0, 0, &deptID, 0, &cbDeptID); SQLBindParameter( stmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR, DEPT_NAME_LEN, 0, deptName, 0,&cbDeptName); SQLBindParameter( stmt, 3, SQL_PARAM_INPUT, SQL_C_SSHORT, SQL_INTEGER, 0, 0, &managerID, 0, &cbManagerID);
Assign values to the parameters.
For example, the following lines assign values to the parameters for the fragment of step 2.
deptID = 201; strcpy( (char * ) deptName, "Sales East" ); managerID = 902;
Commonly, these variables would be set in response to user action.
Execute the statement using SQLExecDirect.
For example, the following line executes the statement string held in
insertstmt on the statement handle
SQLExecDirect( stmt, insertstmt, SQL_NTS) ;
Bind parameters are also used with prepared statements to provide performance benefits for statements that are executed more than once. For more information, see Executing prepared statements
The above code fragments do not include error checking. For a complete sample, including error checking, see samples-dir\SQLAnywhere\ODBCExecute\odbcexecute.cpp.
For more information about SQLExecDirect, see SQLExecDirect in the Microsoft ODBC Programmer's Reference.