SQLite_Exec_Callback

[Eddy Larsson]

Hi
Maybe I misunderstand the function but I do not get the SQLite_Exec_Callback function to work.

It returns only the first column name with value even if there are more columns in the table.
Accompany modified code with a table of 4 kolummer from 'sqllite execute' example.

regards
Eddy

Code Select Expand

' ########################################################################################
' Microsoft Windows
' File: CSQLITE_Exec.bas
' Contents: CSQLite class example
' Connects to a database and reads records.
' Copyright (c) 2012 José Roca. Freeware. Use at your own risk.
' Portions Copyright (c) Microsoft Corporation. All Rights Reserved.
' THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
' EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF
' MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
' ########################################################################################

#COMPILE EXE
#DIM ALL
#INCLUDE ONCE "CSQLite.INC"

' ========================================================================================
' Main
' ========================================================================================
FUNCTION PBMAIN

   ' // Create an instance of the class
   LOCAL pSQL AS ISQLite
   pSQL = CLASS "CSQLite"
   IF ISNOTHING(pSQL) THEN EXIT FUNCTION

   ' // Create a connection object
   LOCAL pDbc AS ISQLiteConnection
   pDbc = pSQL.Connection
   IF ISNOTHING(pDbc) THEN EXIT FUNCTION

   TRY
      ' // Delete our test database if it exists
      IF ISFILE(EXE.PATH$ & "TestA.sdb") THEN KILL EXE.PATH$ & "TestA.sdb"
      ' // Create a new database
      pDbc.OpenDatabase(EXE.PATH$ & "TestA.sdb")
      ' // Create a table
      LOCAL sql AS STRING
      Sql = "CREATE TABLE t (xyz text,A text ,B text, C text)"
      pDbc.Exec(sql)
      ' // Prepare the statement
      sql = "INSERT INTO t (xyz,A,B,C) VALUES ('fruit','A1','B1','C1')" 'Add more colums
      LOCAL pStmt AS ISQLiteStatement
      pStmt = pDbc.Prepare(sql)
      ' // Bind the text
     ' pStmt.BindText(1, "Cfruit")
   
      pStmt.Step
      ? "Row id was" & STR$(pDbc.LastInsertRowId)
      ' // Delete the prepared statement
      pStmt = NOTHING
      ' // Close the database
      pDbc.CloseDatabase
      ' // Open existing database for reading
      pDbc.OpenDatabase2(EXE.PATH$ & "TestA.sdb", %SQLITE_OPEN_READONLY)
      ' // Create a table
      Sql = "SELECT * FROM t"
     
     pDbc.Exec(sql, CODEPTR(SQLite_Exec_Callback))
     
   CATCH
     ' // Display error information
      ? pSql.OleErrorInfo
   END TRY

   ' // Cleanup
   pDbc = NOTHING   ' // Closes the database
   pSQL = NOTHING

   #IF %DEF(%PB_CC32)
      WAITKEY$
   #ENDIF

END FUNCTION
' ========================================================================================

' ========================================================================================
' Callback function for the Exec method.
' Return value:
' If returns non-zero, the Exec method returns SQLITE_ABORT without invoking the callback
' again and without running any subsequent SQL statements.
' ========================================================================================
FUNCTION SQLite_Exec_Callback CDECL(BYVAL pData AS DWORD, BYVAL numCols AS LONG, BYVAL pszColValues AS ASCIIZ PTR, BYVAL pszColNames AS ASCIIZ PTR) AS LONG

   LOCAL i AS LONG
   FOR i = 0 TO numCols - 1
      ? "Column name: " & @@pszColNames[i]
      ? "Column value: " & @@pszColValues[i]
   NEXT
   ? "Number of col: "str$(numCols) & " <----------------"
END FUNCTION

[José Roca]

Then use:

Code Select Expand


' ========================================================================================
' Callback function for the Exec method.
' Return value:
' If returns non-zero, the Exec method returns SQLITE_ABORT without invoking the callback
' again and without running any subsequent SQL statements.
' ========================================================================================
FUNCTION SQLite_Exec_Callback CDECL(BYVAL pData AS DWORD, BYVAL numCols AS LONG, BYVAL pszColValues AS ASCIIZ PTR, BYVAL pszColNames AS ASCIIZ PTR) AS LONG

   LOCAL i AS LONG

   REDIM ColValues (0 TO numCols) AS ASCIIZ PTR AT pszColValues
   REDIM ColNames (0 TO numCols) AS ASCIIZ PTR AT pszColNames
   
   FOR i = 0 TO numCols - 1
      ? "Column name: " & @ColNames(i)
      ? "Column value: " & @ColValues(i)
   NEXT

END FUNCTION
' ========================================================================================


[Eddy Larsson]

Thanks for the code. It works fine.

Regards
Eddy