Core functionality of HTML5 WebDatabases

WebDatabase.js

var db = openDatabase("short_name" // actual database name.  Opens existing or creates.
    , "1" // version number.  *Must* be correct.
    , "a long descriptiony thing" // I do not know where this is useful.  Nothing seems to see it...
    , 10 * 1024*1024); // for 10 megabytes

// also: db.readTransaction(); identical to below, but read-only access to the database.
db.transaction(function(tx){
    tx.executeSql("select * from your_table where aColumn = ?"
        , ["aParameter"] // ? + [data] guards against injection, and is the *only* safe way to do so.  One data item per ?, in order.
        , function(tx, results) { // success callback
            // results contains the num of rows affected, similar to other SQL engines
            console.log("Rows affected: " + results.rowsAffected);
            
            for(var i = 0; i < results.rows.length; i++){
                // Do things with the row item here
                var item = results.rows.item(i);
                // item = {column:value, column:value}
                
                // If you inserted:
                var last_inserted_rowid = results.insertId
                // otherwise this throws an exception!!!
            }
        }
        , function(tx, error) { // error callback
            console.error("code: " + error.code + "\n" + "message: " + error.message);
        }
    );
});