TDbOdbc / TDbOdbcDirect

Fuente: source/classes/tdbodbc.prg / source/classes/tdbodbcd.prg

TDbOdbc provides RDD-compatible ODBC access to SQL databases. It wraps ODBC statement handles and presents a DBF-like interface (GoTop, Skip, FieldGet, etc.), making it possible to browse SQL tables using the same navigation patterns as DBF files. TDbOdbcDirect is a lighter alternative that works directly with TDatabase-compatible ODBC connections without the full RDD emulation layer.

TDbOdbc - Key DATA Members

DATA	Type	Description
`hStmt`	Handle	ODBC statement handle
`oOdbc`	Object	TODBC connection object
`aFields`	Array	Array of field definition arrays
`aFldPrimary`	Array	Primary key field names
`aBuffer`	Array	Current record buffer
`aIndex`	Array	Index/sort order definition
`cSource`	Character	Source table name or SQL
`cSelect`	Character	Generated SELECT statement
`cOrder`	Character	Current ORDER BY clause
`cFilter`	Character	Current WHERE filter
`nRecno`	Numeric	Current record number
`nFields`	Numeric	Number of fields
`lBof / lEof`	Logical	Boundary indicators
`lReadOnly`	Logical	Read-only mode
`lFound`	Logical	Result of last Seek

TDbOdbc - Methods

Method	Description
`New( cSource, oOdbc, nArea, cAlias, lShared, lReadOnly )`	Create and open ODBC table access
`End()`	Close statement handle and release resources
`Execute( cCommand )`	Execute an SQL command directly
`GoTop() / GoBottom()`	Navigate to first/last record
`Skip( nRecs )`	Move relative by n records
`GoTo( nRecNo )`	Go to a specific record by ID
`FieldGet( nField )`	Get field value from current buffer
`FieldPut( nField, uValue )`	Set field value (marks for update)
`FieldName( nField )`	Get SQL column name
`FieldType( nField )`	Get DBF-compatible field type
`FieldLen( nField )`	Get field length
`FieldDec( nField )`	Get field decimal places
`FieldPos( cFieldName )`	Get field position by name
`FCount()`	Number of fields
`Seek( cExpression )`	Seek for expression in current order
`SetOrder( cOrder )`	Set ORDER BY clause
`SetFilter( cFilter )`	Set WHERE filter clause
`Update( lForced )`	Write pending changes to database
`Append()`	Add a new empty record
`Delete()`	Delete current record
`GenDbf( cFile, lWithData, cRdd )`	Generate a DBF file from the SQL result set
`Refresh( lComplete )`	Re-fetch data from server

TDbOdbcDirect - Key DATA and Methods

Member	Description
`New( cSelect, oConnect )`	Create object with SELECT statement and TODBC connection
`Open()`	Open the cursor and start fetching
`Execute( cCommand )`	Execute SQL through the connection object
`FieldGet( nField )`	Get field value via DBF alias
`FieldName( nField )`	Get field name
`FieldType( nField )`	Get field type
`FieldLen( nField )`	Get field length
`FieldPos( cField )`	Get field position by name
`FCount()`	Number of fields
`GoTop() / GoBottom() / Skip( nRecs )`	Navigation
`RecNo() / GoTo( nRecNo )`	Position by record number
`AddNew() / Edit() / Update()`	Record editing
`Refresh()`	Re-fetch data from server
`AutoFill( oWnd, nInterval, bEval )`	Auto-refresh data on a timer
`End()`	Close cursor and release

Example: ODBC Table Browse

#include "FiveWin.ch"

function Main()

   local oOdbc, oTable, oWnd, oBrw

   oOdbc := TODBC():New( "MyDB" )  // ODBC data source name

   if oOdbc == nil
      MsgStop( "Cannot connect to ODBC source" )
      return nil
   endif

   oTable := TDbOdbc():New( "Employees", oOdbc )

   if oTable:lError
      MsgStop( "Cannot open table" )
      return nil
   endif

   DEFINE WINDOW oWnd TITLE "Employees from ODBC"

   @ 0, 0 XBROWSE oBrw OF oWnd AUTOSORT
   oBrw:SetRdd()
   oBrw:SetADO( oTable )     // link TDbOdbc to XBrowse
   oBrw:CreateFromCode()

   ACTIVATE WINDOW oWnd MAXIMIZED

   oTable:End()

return nil

Notes