Querying a Public Window in C/C++

Sybase CEP Server supports public windows, which you can query from outside the server.

Public windows are created with the CREATE PUBLIC WINDOW statement. For an overview of public windows, see Public Windows. For syntax and other information about the CREATE PUBLIC WINDOW statement, see Sybase CEP CCL Reference Guide .

The API functions for querying a public window are shown below:

C8WindowQueryResultSet *C8QueryWindow(const char *i_mgr_uri, const char *i_workspace_name, const char *i_project_name, const char *i_sql); – Purpose: Submits a query of a public window and returns the result set.
Parameters:
- i_mgr_uri: The URI of the server/manager.
- i_workspace_name: The name of the workspace that contains the public window.
- i_project_name: The name of the project that defines the window.
- i_sql: A string that contains the text of the query to execute.
Returns: The result/set or NULL. The returned result/set needs to be destroyed with C8WindowQueryResultDestroy().
C8WindowQueryResultSet *C8QueryWindowA(const char *i_mgr_uri, const char *i_workspace_name, const char *i_project_name, const char *i_sql, const C8UserCredentials *i_credentials); – Purpose: Submits a query of a public window and returns the result set. This function includes a parameter that allows you to specify the credentials of the user whom you want to act as. For general information about user authentication, see the Sybase CEP Installation Guide . For more information about user authentication and the Sybase CEP C/C++ SDK, see User Authentication.
Parameters:
- i_mgr_uri: The URI of the server/manager.
- i_workspace_name: The name of the workspace that contains the public window.
- i_project_name: The name of the project that defines the window.
- i_sql: A string that contains the text of the query to execute.
- i_credentials: Credentials (user name and password).
Returns: The result/set or NULL.

Important: The returned result/set needs to be destroyed with C8WindowQueryResultDestroy().
void C8WindowQueryResultDestroy(C8WindowQueryResultSet *i_result); – Purpose: Frees the given public window query result/set.
Parameters:
- i_result: A valid pointer to a query result/set.
Returns: Nothing.
const C8Schema *C8WindowQueryResultGetSchema(C8WindowQueryResultSet *i_result); – Purpose: Returns the schema corresponding to the result of the public window query. The returned schema remains valid while the C8WindowQueryResultSet remains valid.
Parameters:
- i_result: A valid pointer to a query result/set.
Returns: The result/set's schema if successful, NULL otherwise.
C8SizeType C8WindowQueryResultGetSize(C8WindowQueryResultSet *i_result); – Purpose: Returns the number of rows in result/set.
Parameters:
- i_result: A valid pointer to a query result/set.
Returns: The number of rows in the result set.
C8WindowQueryGetRowByPos(C8WindowQueryResultSet *i_result, C8SizeType i_pos); – Purpose: Gets a message by position. This represents a row in query result/set.
Parameters:
- i_result: A valid pointer to a query result/set.
- i_pos: A valid row number. The number should be between 0 and C8WindowQueryResultGetSize() -1 (inclusive).
Returns: The requested message.

The message must be deleted with C8MessageDestroy().

The following code provides an example of querying a public window:

/* Example: Query a public window */ 
... 
/* Submit the query and get the result set */ 
C8WindowQueryResultSet *res = C8QueryWindow( 
        "http://manager:12345", 
        "Default", 
        "MyPublicWindowProject", 
        "SELECT * FROM MyPublicWindow" 
        ); 
/* If there is a result set (res is not NULL)...*/ 
if (res) { 
    /* Get the number of rows in the resultset */ 
    C8SizeType row_count = C8WindowQueryResultGetSize(res); 
    /* For each row/message in the resultset ... */ 
    for (C8SizeType ii = 0; ii < row_count; ++ii) { 
        /* Get the message out of the resultset */ 
        C8Message *msg = C8WindowQueryGetRowByPos(res, ii); 
        /* use the message here 
        ... 
        */ 
        /* Destroy message when done using it */ 
        C8MessageDestroy(msg); 
    } 
    /* destroy result set when it's no longer needed */ 
    C8WindowQueryResultDestroy(res); 
} 
...