同步两个数据库 MS Access 对象的程序

Question

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

当我们运行程序和select两个数据库。它会将第二个数据库的 table2,table3 创建到第一个数据库中。

Interface Image

程序可以成功生成待生成列表table。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

函数的输出是在更改之前：

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，出现了错误 "Syntax error in field definition"。所以我稍微改变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) );

在生成上面的 SQL 之后，错误是一样的。我想要的只是有关 create table 语句的帮助。下面是Table2的图片，其中的create table语句就是。 Table2 image

Answer 1

我的数据库中的代码，用于在后端创建 table 并编辑 table 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。但是今天我发现了创建 table.

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 SQL 创建的 table 与通过 MS Access Interface 创建的

之间存在一些差异。

同步两个数据库 MS Access 对象的程序

A program to synchronize the objects of two databases MS Access

database

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ms-access

adodb