Question

我正在使用ADODB在VB 2005中开发一个程序。考虑两个MS Access数据库。一个用table1，另一个用table2，table3。

当我们运行程序并选择两个数据库时。它将第二个数据库的table2，table3创建到第一个数据库中。

程序可以成功生成要生成的表列表。之后我有另一个函数来创建“CREATE TABLE”语句。

Function CreateCreateTableStatement(ByVal DBPath As String, ByVal TableName As String) As String
        On Error GoTo EndErr
        Dim cnn As New ADODB.Connection
        Dim TablesSchema, ColumnsSchema, PrimaryKeysSchema As ADODB.Recordset
        Dim tempsql, PrimaryKeyColumn As String
        Dim i As Integer = 0
        cnn.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source='" & DBPath & "';"
        cnn.Mode = ADODB.ConnectModeEnum.adModeShareExclusive
        DoLog("Getting tables list of " & DBPath)
        cnn.Open()
        TablesSchema = cnn.OpenSchema(ADODB.SchemaEnum.adSchemaTables)
        TablesSchema.Filter = "TABLE_NAME = '" & TableName & "'"
        PrimaryKeysSchema = cnn.OpenSchema(ADODB.SchemaEnum.adSchemaPrimaryKeys)
        PrimaryKeysSchema.Filter = "TABLE_NAME = '" & TableName & "'"
        If PrimaryKeysSchema.EOF = False Then PrimaryKeyColumn = PrimaryKeysSchema("COLUMN_NAME").Value
        PrimaryKeysSchema.Close()
        ColumnsSchema = cnn.OpenSchema(ADODB.SchemaEnum.adSchemaColumns)
        ColumnsSchema.Filter = "TABLE_NAME = '" & TableName & "'"
        tempsql = "CREATE TABLE " & TableName & " ("
        Do While Not ColumnsSchema.EOF
            tempsql = tempsql + ColumnsSchema("COLUMN_NAME").Value & " " & DataCodeToName(ColumnsSchema("DATA_TYPE").Value) & " " & " (" & ColumnsSchema("CHARACTER_MAXIMUM_LENGTH").Value & ") " '& ColumnsSchema("IS_NULLABLE").Value & ColumnsSchema("COLUMN_DEFAULT").Value & ", " & ColumnsSchema("IS_NULLABLE").Value & ", " & DataCodeToName(ColumnsSchema("DATA_TYPE").Value) & ", " & ColumnsSchema("CHARACTER_MAXIMUM_LENGTH").Value
            If PrimaryKeyColumn = ColumnsSchema("COLUMN_NAME").Value Then tempsql = tempsql + " PRIMARY KEY, " Else tempsql = tempsql + ", "
            ColumnsSchema.MoveNext()
        Loop
        tempsql = tempsql.Substring(0, Len(tempsql) - 2) + ");"
        cnn.Close()
        DoLog("Gotten tables list of " & DBPath)
        Return tempsql
        Exit Function
EndErr:
        cnn.Close()
        MsgBox(Err.Description)
    End Function

在更改之前输出功能：

CREATE TABLE Table2 (Column1 VARCHAR, Column11 UNSIGNED BYTE, Column12 SHORT, Column13 SINGLE, Column14 DOUBLE, Column15 Guid, Column16 NUMERIC, Column2 VARCHAR, Column3 LONG, Column4 DateTime, Column5 CURRENCY, Column6 LONG PRIMARY KEY, Column7 BIT, Column8 BINARY, Column9 VARCHAR);

但是在执行SQL之后，引发了错误“字段定义中的语法错误”。所以我稍微更改了函数并添加了最大长度，如上面的代码所示。上面的代码生成了SQL：

CREATE TABLE Table2 (Column1 VARCHAR  (255) , Column11 UNSIGNED BYTE  () , Column12 SHORT  () , Column13 SINGLE  () , Column14 DOUBLE  () , Column15 LONG  () , Column16 DECIMAL  () , Column2 VARCHAR  (0) , Column3 LONG  () , Column4 DateTime  () , Column5 CURRENCY  () , Column6 LONG  ()  PRIMARY KEY, Column7 BIT  (2) , Column8 BINARY  (0) , Column9 VARCHAR  (0) );

生成上述SQL后，错误是一样的。我想要的只是关于create table语句的帮助。下面是Table2的图像，其中create table语句是。 Table2 image

Answer 1

我的数据库中的代码在后端创建表并编辑表属性：

If IsNull(Me.tbxTestNum) Then
    MsgBox "Must enter test number.", vbCritical, "Error"
Else
    Set cn = New ADODB.Connection
    'connect to the backend database
    cn.Open "Provider=Microsoft.ACE.OLEDB.12.0; Data Source='" & gstrBasePath & "Data\LabData.accdb'"
    'create the test table
    cn.Execute "CREATE TABLE " & Me.tbxTestNum & " (LabNum text(12) PRIMARY KEY Not Null, method text(30) Not Null);"

    'set table link
    Set tdf = CurrentDb.CreateTableDef(Me.tbxTestNum)
    tdf.SourceTableName = Me.tbxTestNum
    tdf.Connect = "; DATABASE=" & gstrBasePath & "Data\LabData.accdb"
    CurrentDb.TableDefs.Append tdf

    Set rs = New ADODB.Recordset
    rs.Open "SELECT * FROM BuildTable;", CurrentProject.Connection, adOpenStatic, adLockPessimistic
    Set db = DBEngine.OpenDatabase(gstrBasePath & "Data\LabData.accdb")
    While Not rs.EOF
        If rs!DataField <> "LabNum" And rs!DataField <> "method" Then
            'create field in new table
            cn.Execute "ALTER TABLE " & Me.tbxTestNum & " ADD COLUMN " & _
                        rs!DataField & " " & IIf(rs!DataType = "Boolean", "Bit", rs!DataType) & _
                        IIf(rs!DataType = "Text", "(" & rs!FieldSize & ")", "") & ";"
        End If
        'must use DAO to set AllowZeroLength property, I don't allow zero length fields and Access defaults to Yes
        If rs!DataType = "Text" Then
            'change the AllowZeroLength default Yes to No
            db.TableDefs(Me.tbxTestNum).Fields(rs!DataField).AllowZeroLength = False
        End If
        rs.MoveNext
    Wend

    rs.Close
    cn.Close
    db.Close

End If

Answer 2

Function CreateCreateTableStatement(ByVal DBPath As String, ByVal TableName As String) As String
        'CREATE [TEMPORARY] TABLE table (field1 type [(size)] [NOT NULL] [WITH COMPRESSION | WITH COMP] [index1] [, field2 type [(size)] [NOT NULL] [index2]
        ' [, …]] [, CONSTRAINT multifieldindex [, …]])
        On Error GoTo EndErr
        Dim cnn As New ADODB.Connection
        Dim TablesSchema, ColumnsSchema, PrimaryKeysSchema As ADODB.Recordset
        Dim tempsql, PrimaryKeyColumn, ColLen As String
        Dim i As Integer
        cnn.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source='" & DBPath & "';"
        cnn.Mode = ADODB.ConnectModeEnum.adModeShareExclusive
        DoLog("Getting tables list of " & DBPath)
        cnn.Open()
        TablesSchema = cnn.OpenSchema(ADODB.SchemaEnum.adSchemaTables)
        TablesSchema.Filter = "TABLE_NAME = '" & TableName & "'"
        PrimaryKeysSchema = cnn.OpenSchema(ADODB.SchemaEnum.adSchemaPrimaryKeys)
        PrimaryKeysSchema.Filter = "TABLE_NAME = '" & TableName & "'"
        If PrimaryKeysSchema.EOF = False Then PrimaryKeyColumn = PrimaryKeysSchema("COLUMN_NAME").Value
        PrimaryKeysSchema.Close()
        ColumnsSchema = cnn.OpenSchema(ADODB.SchemaEnum.adSchemaColumns)
        ColumnsSchema.Filter = "TABLE_NAME = '" & TableName & "'"
        'ColumnsSchema.Sort = "`ORDINAL_POSITION`"
        tempsql = "CREATE TABLE `" & TableName & "` ("
        Do While Not ColumnsSchema.EOF
            If ColumnsSchema("CHARACTER_MAXIMUM_LENGTH").Value.ToString = "" Or ColumnsSchema("CHARACTER_MAXIMUM_LENGTH").Value.ToString = "0" Then ColLen = "" 'Else ColLen = "(" & ColumnsSchema("CHARACTER_MAXIMUM_LENGTH").Value & ")"
            tempsql = tempsql & "`" & ColumnsSchema("COLUMN_NAME").Value & "` " & DataCodeToName(ColumnsSchema("DATA_TYPE").Value) & " " & ColLen ' & ColumnsSchema("IS_NULLABLE").Value & ColumnsSchema("COLUMN_DEFAULT").Value & ", " & ColumnsSchema("IS_NULLABLE").Value & ", " & DataCodeToName(ColumnsSchema("DATA_TYPE").Value) & ", " & ColumnsSchema("CHARACTER_MAXIMUM_LENGTH").Value
            If PrimaryKeyColumn = ColumnsSchema("COLUMN_NAME").Value Then tempsql = tempsql + " NOT NULL IDENTITY PRIMARY KEY, " Else tempsql = tempsql + ", "
            ColumnsSchema.MoveNext()
        Loop
        tempsql = tempsql.Substring(0, Len(tempsql) - 2) + ");"
        cnn.Close()
        DoLog("Gotten tables list of " & DBPath)
        Return tempsql
        Exit Function
EndErr:
        cnn.Close()
        MsgBox(Err.Description)
    End Function

谢谢你们。但是今天我发现了用于创建表格的正确SQL。

CREATE TABLE `Table3` (`Column1` VARCHAR , `Column11` BYTE , `Column12` SHORT , `Column13` SINGLE , `Column14` DOUBLE , `Column15` GUID , `Column16` DECIMAL , `Column2` VARCHAR , `Column3` LONG , `Column4` DateTime , `Column5` CURRENCY , `Column6` LONG  NOT NULL IDENTITY PRIMARY KEY, `Column7` BIT , `Column8` OLEOBJECT , `Column9` VARCHAR );

一切正常，但上面的SQL创建的表与通过MS Access Interface创建的表之间存在一些差异。

一个程序，用于同步两个数据库MS Access的对象

2 个答案: