Question

我有一个小的访问工具，我想在其中读取链接表并更新本地表。导入新条目的工作原理很像，但是当我尝试更新现有条目时，总是会引发异常（运行时错误3073）。

这是我的代码

Sub UpdateBLPNR()
With CurrentDb
    Set tdf = .CreateTableDef("ext_BEL_PLZ")
    tdf.Connect = "ODBC;DSN=EasyProd PPS;DataDirectory=PATH;SERVER=NotTheServer;Compression= ;DefaultType=FoxPro;Rows=False;Language=OEM;AdvantageLocking=ON;Locking=Record;MemoBlockSize=64;MaxTableCloseCache=5;ServerTypes=6;TrimTrailingSpaces=False;EncryptionType=RC4;FIPS=False"
    tdf.SourceTableName = "BEL_PLZ"
    .TableDefs.Append tdf
    .TableDefs.Refresh
End With

Dim SQLUpdate As String
Dim SQLInsert As String
SQLUpdate = "UPDATE BEL_PLZ " & _
            "INNER JOIN ext_BEL_PLZ " & _
            "ON(BEL_PLZ.NR = ext_BEL_PLZ.NR) " & _
            "SET BEL_PLZ.BEZ = ext_BEL_PLZ.BEZ "
SQLInsert = "INSERT INTO BEL_PLZ (NR,BEZ) " & _
            "SELECT NR,BEZ FROM ext_BEL_PLZ t " & _
            "WHERE NOT EXISTS(SELECT 1 FROM BEL_PLZ s " & _
            "WHERE t.NR = s.NR) "
DoCmd.SetWarnings False
DoCmd.RunSQL (SQLUpdate)
DoCmd.RunSQL (SQLInsert)
DoCmd.SetWarnings True

DoCmd.DeleteObject acTable, "ext_BEL_PLZ"
End Sub

已经发现Access使用链接表更新本地表可能会遇到一些问题，但我无法解决。

（SQLInsert正在运行，SQLUpdate正在杀死我）

这是我的最终可行的解决方案（感谢ComputerVersteher）->

Sub UpdateBLPNR()
'Define Variables
Dim SQLUpdate As String
Dim SQLInsert As String
Dim qdf As DAO.QueryDef
'Create temporary table and update entries
With CurrentDb
    Set tdf = .CreateTableDef("ext_BEL_PLZ")
    tdf.Connect = "ODBC;DSN=EasyProd PPS;DataDirectory=PATH;SERVER=NotTheServer;Compression= ;DefaultType=FoxPro;Rows=False;Language=OEM;AdvantageLocking=ON;Locking=Record;MemoBlockSize=64;MaxTableCloseCache=5;ServerTypes=6;TrimTrailingSpaces=False;EncryptionType=RC4;FIPS=False"
    tdf.SourceTableName = "BEL_PLZ"
    .TableDefs.Append tdf
    .TableDefs.Refresh
     With .OpenRecordset("SELECT ext_BEL_PLZ.NR, ext_BEL_PLZ.BEZ " & _
                        "FROM ext_BEL_PLZ INNER JOIN BEL_PLZ ON BEL_PLZ.NR = ext_BEL_PLZ.NR", dbOpenSnapshot)
        Set qdf = .Parent.CreateQueryDef("")
        Do Until .EOF
             qdf.sql = "PARAMETERS paraBEZ Text ( 255 ), paraNr Text ( 255 );" & _
                       "Update BEL_PLZ Set BEL_PLZ.BEZ = [paraBEZ] " & _
                       "Where BEL_PLZ.NR = [paraNr]"
             qdf.Parameters("paraBez") = .Fields("BEZ").Value
             qdf.Parameters("paraNr") = .Fields("NR").Value
             qdf.Execute dbFailOnError
             .MoveNext
        Loop
    End With
End With
'Run SQL Query (Insert)
SQLInsert = "INSERT INTO BEL_PLZ (NR,BEZ) " & _
            "SELECT NR,BEZ FROM ext_BEL_PLZ t " & _
            "WHERE NOT EXISTS(SELECT 1 FROM BEL_PLZ s " & _
            "WHERE t.NR = s.NR) "
DoCmd.SetWarnings False
DoCmd.RunSQL (SQLInsert)
DoCmd.SetWarnings True
'Drop temporary table
DoCmd.DeleteObject acTable, "ext_BEL_PLZ"
End Sub

Answer 1

你不能那样做。

除Access本身以外的其他数据源上的链接表需要主键来支持更新。

通过GUI进行链接时，Access确实允许您指定一个备用键，如果没有主键，但如果有主键应唯一地标识行。

Answer 2

从只读表创建记录集以获取值。

#!/bin/bash

directory="/path/to/log_dir"
threshold=150
output="/path/to/log-$(date +"%Y-%m-%d").zip"

dir_size=$(du -k $directory | cut -f1)
if [ "$dir_size" -gt "$threshold" ]
then
    zip -r $output $directory
fi

访问-使用链接表更新本地表（但没有主键）

2 个答案: