Visual FoxPro 9 C＃OleDbAdapter插入-功能不可用

Question

How do I insert into a FoxPro table with a primary key whose default value is newid("tablename") using Microsoft's OLE DB Provider for Visual Foxpro 9.0 ?

I have two tables, one where the primary key has a default value of newid("tablename") , and the other whose data type is set to Integer (AutoInc) .

When I try to run the same insert command on the newid table, I get the following OleDbException :

Feature is not available

When I run insert on the table with Integer (AutoInc) as the primary key, it works.

Here is the code I am trying to execute:

public void InsertData()
{
    using(var connectionHandler = new OleDbConnection("Provider=VFPOLEDB.1;Data Source=\"C:\\path\\to\\db.dbc\";"))
    {
        var insertStatement = @"INSERT INTO mytable (mycol) values (?)";

        var insertCommand = new OleDbCommand(insertStatement, connectionHandler);

        insertCommand.Parameters.Add("mycol", OleDbType.Char).Value="blue";

        connectionHandler.Open();
        insertCommand.ExecuteNonQuery();
        connectionHandler.Close();
    }
}

Is there any reason OLE would not be able to execute an insert because of this newid() default value?

---

Another case that fixes my issue is if I manually specify an id in the insert clause. ex:

var insertStatement = @"INSERT INTO mytable (id, mycol) values (?, ?)";
insertCommand.Parameters.Add("id", OleDbType.Integer).Value = 199;
insertCommand.Parameters.Add("mycol", OleDbType.Char).Value = "blue";

Additionally, I am able to run a select * from tablename on this table.

select snippet:

public DataTable GetData()
{
    var myData = new DataTable();

    using(var connectionHandler = new OleDbConnection("Provider=VFPOLEDB.1;Data Source=\"C:\\path\\to\\db.dbc\";"))
    {       
        var da = new OleDbDataAdapter();
        var mySQL = "select * from mytable";

        var myQuery = new OleDbCommand(mySQL, connectionHandler);
        connectionHandler.Open();

        da.SelectCommand = myQuery;

        da.Fill(myData);

        connectionHandler.Close();
    }

    return myData;
}

newid() SP:

function newId
parameter thisdbf
regional keynm, newkey, cOldSelect, lDone
keynm=padr(upper(thisdbf),50)
cOldSelect=alias()
lDone=.f.
do while not lDone
    select keyvalue from main!idkeys where keyname=keynm into array akey
    if _tally=0
        insert into main!idkeys (keyname) value (keynm)
        loop
    endif
    newkey=akey+1
    update main!idkeys set keyvalue=newkey where keyname=keynm and keyvalue=akey
    if _tally=1
        lDone=.t.
    endif
enddo
if not empty(cOldSelect)
    select &cOldSelect
else
    select 0
endif
return newkey

In a separate stored procedure, I have tried the following to isolate the key word regional :

FUNCTION GetHello

regional hello

RETURN "HELLO WORLD"

Which seems to work (for example, setting the default value of a column to GetHello() then running an insert over OLEDB).

The following causes my stored procedure to fail with "Feature is not available" over OLEDB:

FUNCTION GetHello
LOCAL test
test="select * from customer"
&test
RETURN "hello"

Answer 1

Thanks for sharing the SP code! It shows what was the culprit.

Though my nerves tend to do many corrections on that code I will only modify enough to make it work from both VFP and C#:

function newId
parameter thisdbf
regional keynm, newkey, nOldSelect, lDone
keynm=padr(upper(thisdbf),50)
nOldSelect=select()
lDone=.f.
do while not lDone
    select keyvalue from main!idkeys where keyname=keynm into array akey
    if _tally=0
        insert into main!idkeys (keyname) value (keynm)
        loop
    endif
    newkey=akey+1
    update main!idkeys set keyvalue=newkey where keyname=keynm and keyvalue=akey
    if _tally=1
        lDone=.t.
    endif
enddo
Select (m.nOldSelect)
return newkey

The changed part is only related to that (if !empty(...)) block .

Answer 2

The issue is this variable declaration line in the stored procedure:

regional keynm, newkey, cOldSelect, lDone

The 'regional' keyword is a holdover from the old FoxPro 2.6 for DOS\\Windows. It was only used in programs generated by the screen builder tool. It obviously still lurks within Visual FoxPro to support functionality that migrates old FoxPro 2.6 projects to Visual FoxPro, because the code works fine in VFP. But the OLEDB driver doesn't support it.

Anyway, you need to change your stored procedure to use:

local keynm, newkey, cOldSelect, lDone

... and recompile it, for which you will need Visual FoxPro. Ensure there are no OLEDB or other connections to it and then in the Visual FoxPro command window:

compile c:\path\to\mydatabase.dbc