As always lets do things in steps.

1. Create necessary variables.
2. Open connection to database file already created.
3. Read schema from opened connection to database.

1. Create necessary variables

private var sqlConnection:SQLConnection;
private var dbFile:File;
private var sqlStatement:SQLStatement;

2. Open connection to database file already created

dbFile=new File();
dbFile=File.applicationStorageDirectory.resolvePath("myDatabase.db");

sqlConnection = new SQLConnection();
sqlConnection.addEventListener(SQLEvent.OPEN, onDBOpened);
sqlConnection.addEventListener(SQLErrorEvent.ERROR, onDBError);
sqlConnection.open(dbFile);

3. Read schema from opened connection to database

//event handler for SQLEvent.OPEN

private function onDBOpened(event:SQLEvent):void
{
 if (event.type == "open")
 {
  //successfully opened database connection

  //below statement loads schema
  sqlConnection.loadSchema();
  //below statement to access the schema
  var sqlSchemaResult:SQLSchemaResult=sqlConnection.getSchemaResult();
  //below statement returns all tables from loaded schema result that is array of SQLTableSchema
  var tables:Array=sqlSchemaResult.tables;			
  for each(var sqlTableSchema:SQLTableSchema in tables)
  {
   trace("Table name:"+sqlTableSchema.name);
   trace("Columns:"+sqlTableSchema.columns);
   //can explore SQLTableSchema Class for more.
  }
 }
}

Hi People, Its been a while i blogged, trying to make it back and hope this post helps someone.