我用下面的代码更改表名为”分层数据表“中的某字段“主层号”大小为100,运行后提示错误:“ALTER TABLE语句中语法错误”,但哪里错了呢? Private Sub Command1_Click() Dim wb As Database Set wb = OpenDatabase("c:\11.mdb") wb.Execute "alter TABLE 分层数据表 MODIFY 主层号 DBTEXT(50)" wb.Close End Sub 若更改其数据类型为数值型integer ,大小不变,又如何写语句?急。
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Private Sub Command1_Click()
Dim wb As Database
Set wb = OpenDatabase("c:\11.mdb")
wb.Execute "alter TABLE 分层数据表 MODIFY 主层号 DBTEXT(50)"
wb.Close
End Sub
若更改其数据类型为数值型integer ,大小不变,又如何写语句?急。
GZ!
ADD | ALTER [COLUMN] FieldName1
FieldType [(nFieldWidth [, nPrecision])]
[NULL | NOT NULL]
[CHECK lExpression1 [ERROR cMessageText1]]
[DEFAULT eExpression1]
[PRIMARY KEY | UNIQUE]
[REFERENCES TableName2 [TAG TagName1]]
[NOCPTRANS] – Or –ALTER TABLE TableName1
ALTER [COLUMN] FieldName2
[NULL | NOT NULL]
[SET DEFAULT eExpression2]
[SET CHECK lExpression2 [ERROR cMessageText2]]
[DROP DEFAULT]
[DROP CHECK] – Or –ALTER TABLE TableName1
[DROP [COLUMN] FieldName3]
[SET CHECK lExpression3 [ERROR cMessageText3]]
[DROP CHECK]
[ADD PRIMARY KEY eExpression3 TAG TagName2]
[DROP PRIMARY KEY]
[ADD UNIQUE eExpression4 [TAG TagName3]]
[DROP UNIQUE TAG TagName4]
[ADD FOREIGN KEY [eExpression5] TAG TagName4
REFERENCES TableName2 [TAG TagName5]]
[DROP FOREIGN KEY TAG TagName6 [SAVE]]
[RENAME COLUMN FieldName4 TO FieldName5]
[NOVALIDATE]ALTER [COLUMN] FieldName1Specifies the name of an existing field to modify.
没有MODIFY ,有ALTER [COLUMN] FieldName1,可以修改表的字段
你的数据丢不丢失跟你所改的数据类型类型有关
Insert Into new_Tb_Name (Fd1,fd2,...fdx) Select Old_Tb_name.Fd1,Old_Tb_name.Fd2,...Old_Tb_name.Fdx From Old_Table_name Order by Fd_Key
其中 Fd 是一一对应的.切记!