Question

我有一个dbf文件，我想执行查询。这是我的代码（.net 4.0，C＃Windows Forms）：

oconn.ConnectionString = "Provider=vfpoledb.1;Data Source=" + path + ";Collating Sequence=machine";
oconn.Open();
OleDbCommand ocmd = oconn.CreateCommand();
string na = TBNazwaKonta.Text.Replace("\n","");
na = na.Replace("\r","") ;
string ks2 = ks.Replace("\n","");
ks2 = ks2.Replace("\r", "");
string zapytanie = @"insert into " + path + " (rk, Na,Ks,Ss,So,Wyr,Bw,Bm,Ow,Om,Wm,Mm,Pm,Pw,Ks1,Ks2,Ks3,Ks4,Llx,Wn01,Ma01,L01,Wn02,Ma02,L02,Wn03,Ma03,L03,Wn04,Ma04,L04,Wn05,Ma05,L05,Wn06,Ma06,L06,Wn07,Ma07,L07,Wn08,Ma08,L08,Wn09,Ma09,L09,Wn10,Ma10,L10,Wn11,Ma11,L11,Wn12,Ma12,L12) values (0,'Z-Dz PROD.OPAKOWAŃKIEWICZA 108   38-200 ', '200 02 000212',0,0,'',0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,'','','','',0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0,0.0,0.0,0)";
ocmd.CommandText = zapytanie;
ocmd.ExecuteNonQuery();
oconn.Close();

连接很好，插入查询也很好，但我想知道为什么这个dbf不接受空值。

我在哪里可以检查dbf是否接受空值？当我使用程序读取dbfs并执行查询时，dbf接受null。它只在我使用ado.net时才接受。感谢您解决我的问题的任何帮助

Answer 1

您可以创建一个新命令并在插入之前执行它。

OleDbCommand dbCmdNull = oconn.CreateCommand();
dbCmdNull.CommandText = "SET NULL OFF";
dbCmdNull.ExecuteNonQuery();

Answer 2

您可以将列设置为不接受空值。

如果您使用的是visual foxpro，请打开您的dbf，转到View＆gt;表设计师您将看到列的列表，最后一列表示它是否接受空值。

那里有一个Null按钮。取消选中该列，您的列将不接受空值。

这将确保您不会写入空值。但是如果有空值，那么你就是在某处写它们。你将不得不修复那段代码。

插入到dbf文件不接受空值

2 个答案: