Using Server-Side Javascript

A Datasource can be a server-side Javascript, and provides a way to process and get data from the server. The Javascript datasource executes on the server and gets the result back from the server.

Function Support for Javascript

• QExecutor.executeSql('sql_query'); The 'sql_query' will be executed and the result set will be converted to SqlResult. This method returns SqlResult.

• QExecutor.executeSql('sql_query', parameterList); The 'sql_query' is treated as prepared statement, parameterList should contain the values that should be used to set the variables of the prepared statement. The result set of execution will be converted to SqlResult. This method returns SqlResult.

• QExecutor.executeSql('sql_query', parameterList, convertToSqlResult); This is a convience function, the convertToSqlResult is a boolean variable which decides whether to convert the result set after execution to SqlResult or ignore it. Set to False, if don't need the SqlResult back. Converting result set to SqlResult might not be need if the result set is too large. This method returns SqlResult if convertToSqlResult is True otherwise it will return null.

• QExecutor.executeNQ('named_query_name', parameterMap); Executes other named query and will return the result.

Setting SQLRESULT

• You have to set SQLRESULT variable in Javascript which will be sent to the client. If it is not set (or null) then the 'out.println statement' from the Javascript will be captured and will be sent as text to client.

Handling Result on Client

• Javascript Named Query can return either SqlResultSet or JavascriptResultSet, here is a generic handler.

   function handler(resultSet, error) {
       if(error != null) {
           alert("Error:" + error.message);
           return;
       } else {
           if(resultSet.type() == "JAVASCRIPT") {
               alert("RESULT: " + resultSet.getResult());
           } else if(resultSet.type() == "SQL") {
               // ... handle sql result set
           } 
       }
    }

Example1

Type: Javascript

var insertnames = PARAM["insertnames"];
var picknames = PARAM["picknames"];

for(var index=0; index < insertnames.length; ++index) {
    QExecutor.executeSql("insert into NameTable(name) values(?)", [insertnames[index]]);
}

SQLRESULT = QExecutor.executeSql("select * from NameTable where name in (?)", [picknames]);

In Javascript Client:

/* var params = { insertnames : ["name1", "name2", "name3"], picknames : ["name2", "name4"] }; */

var params = new Object();
params["insertnames"] =  ["name1", "name2", "name3"];
params["picknames"] =  ["name2", "name4"];

var ajaxdb = new Applibase.db.AjaxDb();
ajaxdb.query("testSqlJavascript", params, true, handler);
function handler(resultSet, error) {
    if(error != null) { alert("Error: " + error.message); }
    else {
        if(resultSet.type() == "SQL") {
            while(resultSet.next()) {
                // ...
            }
        } else if(resultSet.type() == "JAVASCRIPT") {
            alert("Result: " + resultSet.getResult());
        }
    }
}