Query’s GetADORecordSet method returns an ADO (ActiveX Data Object) type Recordset, resulting from the execution of the configured query.
The ADO Recordset object is used to access a chart’s record in the database. It has the following properties and methods:
Properties:
BOF: Returns true if the position of the pointer is previous to the first record.
EOF: Returns true if the position of the pointer is posterior to the last record.
RecordCount: Returns the number of records in the chart.
Methods:
MoveFirst: Moves the pointer to the first record.
MoveLast: Moves the pointer to the last record.
MoveNext: Moves the pointer to the next record.
MovePrevious: Moves the pointer to the previous record.
To access the records individually, we use Fields (“FieldName”) command.
Example:
set RS = Screen.Item(“Query1”).GetADORecordset()
for i=1 to RS.RecordCount
Field1 = RS.Fields(“Field1”).Value
Field2 = RS.Fields(“Field2”).Value
Field3 = RS.Fields(“Field3”).Value
MsgBox Field1 &vbTab& Field2 &vbTab& Field3
next
Exercises:
1. Insert a Database object in the project and configure it.
2. Create 3 demonstration tags and record them in the Database using the Historic object. In the Historic, set recording time to 0 seconds.
3. Insert a button on screen that when clicking records a register in the Historic. (WriteRecord)
4. Insert a query object on screen that searches the data saved by the Historic.
5. Create a button on screen that when clicking, displays every row in the Historic. Use the While command to repeat the script until it has not reached the end of the chart.
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