While converting my code (to make compatible with A, i, J) from using:
Private Cursor as Cursor
--- to:
Private Cursor as ResultSet
I found the need to determine if the dataset has any rows... (like: Cursor.RowCount - which does not exist in ResultSet).
I added this method to my DBUtils module. I noticed Erel used this:
If cur.NextRow = True - in other methods to determine if (rows > 0) in resultset.
Typical useage:
Thanks
Private Cursor as Cursor
--- to:
Private Cursor as ResultSet
I found the need to determine if the dataset has any rows... (like: Cursor.RowCount - which does not exist in ResultSet).
I added this method to my DBUtils module. I noticed Erel used this:
If cur.NextRow = True - in other methods to determine if (rows > 0) in resultset.
B4X:
'Executes the query and returns True if ResultSet has data
' Appends " LIMIT 1" to query passed to make it "light" (one record)
'
Public Sub HasRecords(SQL As SQL, Query As String, StringArgs() As String) As Boolean
Dim res As Boolean = False
Query = Query&" LIMIT 1"
Dim cur As ResultSet
If StringArgs <> Null Then
cur = SQL.ExecQuery2(Query, StringArgs)
Else
cur = SQL.ExecQuery(Query)
End If
Log("Execute this query for recs: " & Query)
If cur.NextRow = True Then
res = True
End If
cur.Close
Return res
End SubTypical useage:
B4X:
Sub GetDivs(id As Int) As Map
Dim ret As Map
ret.Initialize
Dim q As String = "SELECT * FROM message_mast where mast_id = "&id ' the query
If DBUtils.HasRecords(Starter.SQL1, q, Null) Then ' check if table has records before proceeding
Dim Cursor As ResultSet ' now get a full result set
Cursor = Starter.SQL1.ExecQuery( q )
Dim i As Int = 0 ' need a row position (index) - since ResultSet doesn't have one..
Do While Cursor.NextRow
Dim dd As Map
dd.Initialize
dd.Put("id",Cursor.GetInt("id"))
dd.Put("mast_id",Cursor.GetInt("mast_id"))
dd.Put("name",Cursor.GetString("name"))
dd.Put("topic_id",Cursor.GetString("topic_id"))
dd.Put("prime",Cursor.GetInt("prime"))
dd.Put("subscribed",Cursor.GetInt("subscribed"))
dd.Put("spare1",Cursor.GetString("spare1"))
dd.Put("spare2",Cursor.GetString("spare2"))
dd.Put("spare3",Cursor.GetString("spare3"))
ret.Put(i,dd)
i = i + 1
Loop
Cursor.Close ' close here - since we actually created a cursor...
End If
Return ret
End SubThanks
Last edited:
