Microsoft KB Archive/107596

FIX: DBCols() with Large Number of Columns Causes GPF ID: Q107596 2.5x 2.6x | 2.5x 2.6x WINDOWS | MS-DOS kbprg kbfixlist kbbuglist The information in this article applies to: Microsoft FoxPro for Windows, versions 2.5x, 2.6x Microsoft FoxPro for MS-DOS, versions 2.5x, 2.6x SYMPTOMS When you are using FoxPro with the Connectivity Kit (CK), executing a DBCols() statement on a SQL Server table with approximately 200 columns in FoxPro for Windows or 150 columns in FoxPro for MS-DOS will cause a general protection (GP) fault in FoxPro for Windows and will cause FoxPro for MS- DOS to hang or crash. STATUS Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was corrected in Visual FoxPro 3.0 for Windows. MORE INFORMATION Steps to Reproduce Problem CAUTION: Save your work and close all other programs before following these steps. This procedure may result in lost data and/or corrupted files. To reproduce the problem, you must have the CK and SQL Server installed. Follow the steps at the top of the following program, and then run the program. ************************************************************************ * SQLTB.PRG * Generates a GP fault in FoxPro for Windows 2.5, 2.5a, 2.5b * Crashes or Locks FoxPro for MS-DOS 2.5, 2.5a, 2.5b * Build a 200 (Windows) or 150 (MS-DOS) column table & execute DBCols() * * Assumes: FPSQL.FLL (Windows) or FPSQL.PLB (MS-DOS) Loaded *  : A valid connection handle to SQL Server *  : In "pubs" database * * Example: From the command window enter the following: *  : SET LIBRARY TO FPSQL.FLL (PLB) *  : mhandle = dbconnect("<DataSource>","<user>","<password>","") *  : mresult = dbexec(mhandle,"use pubs") *  : DO sqltb WITH "<tabletocreate>" ************************************************************************ PARAMETERS p_table IF PARAMETERS()=0 WAIT WINDOW "You must pass a table name to this procedure.." RETURN ENDIF SET TALK OFF * Initialize variables PUBLIC msqlc PUBLIC msqle PUBLIC mresult PUBLIC mtable STORE SPACE(10) TO msqlc,msqle STORE 0 TO mresult IF TYPE("mhandle") = "U" STORE 1 TO mhandle ENDIF mtable = "dbo."+p_table * Build SQL CREATE TABLE command string msqlc = "create table &mtable (" WAIT WINDOW "Command string:"+msqlc+" will be created" TIMEOUT 2 WAIT WINDOW NOWAIT "Creating SQL command string.." FOR i = 1 TO IIF(_WINDOWS,200,150) mvar = "C" + ukey(9)+" char(10)," msqlc = msqlc + mvar ENDFOR msqlc = LEFT(msqlc, LEN(msqlc)-1)+")" WAIT WINDOW NOWAIT "Create table string built.." mresult = dbexec(mhandle,msqlc) IF mresult = 1 WAIT WINDOW "Table created.." TIMEOUT 2 ELSE WAIT WINDOW "Error - table not created.." timeout 5  ? alltrim(sqe()) ENDIF IF mresult = 1 WAIT WINDOW "Attempt dbcols() on new table.." TIMEOUT 2 mresult = dbcols(mhandle,mtable)  ? mresult ELSE WAIT WINDOW "Please clear error condition and rerun" TIMEOUT 5 ENDIF SET TALK ON FUNCTION ukey * Return unique key of length <lenkey> PARAMETER lenkey IF PARAMETERS()=0 lenkey=8 ENDIF IF lenkey=1 RETURN RIGHT(SYS(3),1) ENDIF len1=FLOOR(lenkey/2) len2=lenkey-len1 key1= RIGHT(SYS(3),len1) key2= RIGHT(SYS(2015),len2) RETURN key1+key2 * EOF ukey FUNCTION sqe * Evaluate and display ODBC Error PRIVATE num,msg,mresult STORE 0 TO num,mresult STORE "" TO msg mresult = dberror(1,@msg,@num) RETURN msg+"/"+ALLTRIM(STR(num,6,0)) * EOF sqe ** EOP sqltb REFERENCES For more information on the Ukey function, please see the following article in the Microsoft Knowledge Base: ARTICLE-ID: Q106708 TITLE  : How to Generate Unique Key Field Values Additional reference words: FoxDos FoxWin VFoxWin 2.50 2.50a 2.50b 2.60 2.60a gpf fixlist 3.00 buglist2.50 buglist2.50a buglist2.50b buglist2.60 buglist2.60a lock up freeze halt stop responding KBCategory: kbprg kbfixlist kbbuglist KBSubcategory: FxtoolCk Keywords  : FxtoolCk kbbuglist kbfixlist Version  : 2.5x 2.6x | 2.5x 2.6x Platform  : MS-DOS WINDOWS Solution Type  : kbfix

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