Question

ADO VB 如何用语句将ACCESS数据库某字段的"必填"属性设置为"假"

VB ADO 如何用语句将ACCESS数据库某字段的"必填"属性设置为"假"
我用ADX建立数据库和数据表:
Dim cat As New ADOX.Catalog
Dim tbl As New ADOX.Table
Dim pstr As String
Dim DB As String

DB = App.Path & "\" & "department.mdb"
pstr = "Provider=Microsoft.Jet.OLEDB.4.0;" '数据库驱动 4.0 For Office 2k/2003, 3.5.1 For Office 97
pstr = pstr & "Data Source=" & DB

cat.Create pstr '建立数据库存
cat.ActiveConnection = pstr

tbl.Name = "单位" '定义表名

tbl.Columns.Append "编号", adInteger '定义字段
tbl.Columns.Append "上级单位编号", adInteger '定义字段
tbl.Columns.Append "铁路局", adVarWChar, 20 '定义字段
tbl.Columns.Append "工务段", adVarWChar, 20 '定义字段
tbl.Columns.Append "车间", adVarWChar, 20 '定义字段
tbl.Columns.Append "巡养站", adVarWChar, 20 '定义字段
tbl.Columns.Append "起点里程", adDouble
tbl.Columns.Append "终点里程", adDouble
cat.Tables.Append tbl '建立表
建立后我要把"编号"字段设为"必填"且"无重复",其它字段设为非必填.请高手指教.

Answer 1

你把字段1设置为自动编号就行了吗!
CREATE TABLE MyCustomers (CustID int IDENTITY (100,1) PRIMARY KEY, CompanyName nvarchar (50)):CustID 设为主键且以1的步长自动递增.