• Chrome,
• Safari,
• Opera 11, ...

1. Use SQLConnect in browser code to connect to the local database. For example:
   

   // Connection to a browser database named "LocalDatabase"
   // The database is created if it does not exist
   SQLConnect("LocalDatabase", "", "", "", "Web SQL database")

2. Use SQLExec to run queries on the local database.
   Please note SQL queries are executed asynchronously. Therefore, the syntax of SQLExec uses a specific procedure. This procedure is started at the end of real query execution (regardless of the query result). This browser procedure is used to:
   • check the proper execution of the query. SQLInfo is automatically run during the call to the procedure. Therefore, all the SQL variables are positioned. If an error occurred, SQL.Error will differ from "00000". The error message is returned by the SQL.MesError variable.
   • browse the query result.
   If new queries are run in this procedure (to add records for example), you can:
   • use the same procedure: the parameter of this procedure is used to find out the query currently run.
   • use a different browser procedure to test the result of these new queries.

• During the exit from the browser procedure, the values returned by SQLInfo are restored. If these values have been modified in the browser procedure, they are overwritten.
• To find out the SQL commands that can be used, see the documentation about the "Web SQL databases".

Available SQL functions

Steps

1. Connecting to the database
   The connection to the database is established with SQLConnect. For example:
   

   SQLConnect("","","", "APTCustomers", "Web SQL database")

2. Creating the local database
   The local database must be created before it can be used. To do so, all you have to do is use a CREATE TABLE query. This query must be run by SQLExec. For example:
   

   sQuery is string
   // Code for creating the table
   sQuery = [
   CREATE TABLE IF NOT EXISTS "Appointments" 
   ("AppointmentID"  INTEGER PRIMARY KEY , "StartDateTime" VARCHAR(16) , 
   "Customer" VARCHAR(100) , "Address" VARCHAR(200) , "Summary" LONGVARCHAR ); 
   ]
   // Execute query 
   SQLExec(sQuery, "QRY_CREATION", _cbQuery)

   
   When the "QRY_CREATION" query is completed, the _cbQuery procedure is run.
   In this example, this procedure is used to manage all the queries run and to perform an appropriate process after the query.
   The creation query must be used once, at the beginning of the day for example. For example, the database can be created only if a specific parameter ("First" for example) is not passed to the pages.
3. Accessing the local or remote data
   In this example, the site can be used in online mode or in offline mode. You must be able to access the local database (in offline mode) or to the remote database (in online mode).
   All the accesses (creation, modification, deletion, ...) to the local database must be performed via the SQLExec procedure.
   The accesses to the remote database can always be performed via the Hxxx functions. However, you must:
   • run these functions in a browser code, therefore in AJAX, via AJAXExecute.
   • make sure that the browser is connected (BrowserIsConnected).
   For example:
   

   sQuery is string 
   // The browser is connected 
   IF BrowserIsConnected() = True THEN 
   	// Saves in the remote database (server) 
   	AJAXExecute(SaveData, EDT_ID, EDT_SUMMARY) 
   END 
   sQuery = [
   	UPDATE Appointment 
   	SET Summary='%2' 
   	WHERE AppointmentID=%1 
   ]
   
   // In any case, save in the local database 
   SQLExec(StringBuild(sQuery, gnBrwAPTID, EDT_SUMMARY), "QRY_BACKUP", _cbQuery)

Retrieving the records found in the remote database

1. Read the records and store the items as strings, in a server procedure.
   

   PROCEDURE GetRec() 
   FOR EACH MyFile1 
   	sList += [CR]+ MyFile1.Item1 + TAB + ...
   		MyFile1.Item2 + TAB + MyFile1.Item3
   END 
   RETURN sList

2. Retrieve this list in browser code:
   

   // Retrieves the list 
   sList = AJAXExecute(GetRec)

3. Browse the string and extract the information with ExtractString. Therefore, the records can be easily added with an addition query (INSERT).

Retrieving the local data to update the remote database

1. Run a query locally to retrieve the records. For example, to retrieve the appointments of the day:
   

   // Runs the query that selects the appointments of the day
   sQuery is string
   sQuery = StringBuild("SELECT AppointmentID,Summary FROM APPOINTMENT " + ...
   	"WHERE StartDateTime LIKE '%1%' ORDER BY StartDateTime ASC;", Today()) 
   // Starts the query
   SQLExec(sQuery, "QRY_SYNCHRONIZEAPT", _cbQuery)

2. In the check procedure started by SQLExec, simply run a procedure for updating the remote database via AJAXExecute. In our example, the browser procedure named __SynchonizeDatabase is started:
   

   PROCEDURE _SynchronizeDatabase(sQuery)
   
   // As long as there are appointments to synchronize
   WHILE SQLFetch(sQuery) = 0
   	// Synchronizes the appointment
   	AJAXExecute(_SynchronizeARemoteAppointment, SQLGetCol(sQuery, 1), SQLGetCol(sQuery, 2))
   END

   Note Remote database update can be triggered when reconnecting to the server. During the reconnection to the server, the "Switch to online mode" event is run. This process is an optional process of the page.

• Display the code of the page.
• Click on the "Add more events to xxx" link at the end of the code window, after the last event.
  
  All the optional events available for the page are displayed.
• Select the "Switch to online mode" event.
• Validate.
• Enter the code for updating the remote database.