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DBEngine.CompactDatabase method (DAO)

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Applies to: Access 2013 | Access 2016

Copies and compacts a closed database, and gives you the option of changing its version, collating order, and encryption. (Microsoft Access workspaces only).

Note

When using encrypted linked tables for action, update, and SQL queries [such as a SQL UPDATE statement (CurrentDb.Execute "UPDATE...")], you must supply the encryption key. Also, linked tables have a 19-character limit for the encryption key. See the Encrypted linked tables section at the end of this topic.

Syntax

expression .CompactDatabase(SrcName, DstName, DstLocale, Options, password)

expression An expression that returns a DBEngine object.

Parameters

Name

Required/optional

Data type

Description

SrcName

Required

String

Identifies an existing, closed database. It can be a full path and file name, such as "C:\db1.mdb". If the file name has an extension, you must specify it. If your network supports it, you can also specify a network path, such as "\\server1\share1\dir1\db1.mdb"

DstName

Required

String

the file name (and path) of the compacted database that you're creating. You can also specify a network path. You can't use this argument to specify the same database file as SrcName.

DstLocale

Optional

Variant

A string expression that specifies a collating order for creating DstName, as specified in Remarks.

  • If you omit this argument, the locale of DstName is the same as SrcName.

  • You can also create a password for DstName by concatenating the password string (starting with ";pwd=") with a constant in the DstLocale argument, like this: dbLangSpanish & ";pwd=NewPassword".

  • If you want to use the same DstLocale as SrcName (the default value), but specify a new password, simply enter a password string for DstLocale: ";pwd=NewPassword"

Options

Optional

Variant

Optional. A constant or combination of constants that indicates one or more options, as specified in Remarks. You can combine options by summing the corresponding constants.

password

Optional

Variant

A string expression containing an encryption key, if the database is encrypted. The string ";pwd=" must precede the actual password. If you include a password setting in DstLocale, this setting is ignored.

NOTE: This is deprecated parameter and is not supported in .ACCDB format. To encrypt an .ACCDB file, use the "pwd=" option string. Use strong passwords that combine upper- and lowercase letters, numbers, and symbols. Weak passwords don't mix these elements. Strong password: Y6dh!et5. Weak password: House27. Use a strong password that you can remember so that you don't have to write it down.

Remarks

You can use one of the following constants for the DstLocale argument to specify the CollatingOrder property for string comparisons of text.

Constant

Collating order

dbLangGeneral

English, German, French, Portuguese, Italian, and Modern Spanish

dbLangArabic

Arabic

dbLangChineseSimplified

Simplified Chinese

dbLangChineseTraditional

Traditional Chinese

dbLangCyrillic

Russian

dbLangCzech

Czech

dbLangDutch

Dutch

dbLangGreek

Greek

dbLangHebrew

Hebrew

dbLangHungarian

Hungarian

dbLangIcelandic

Icelandic

dbLangJapanese

Japanese

dbLangKorean

Korean

dbLangNordic

Nordic languages (Microsoft Jet database engine version 1.0 only)

dbLangNorwDan

Norwegian and Danish

dbLangPolish

Polish

dbLangSlovenian

Slovenian

dbLangSpanish

Traditional Spanish

dbLangSwedFin

Swedish and Finnish

dbLangThai

Thai

dbLangTurkish

Turkish

You can use one of the following constants in the options argument to specify whether to encrypt or to decrypt the database while it's compacted.

Note

The constants dbEncrypt and dbDecrypt are deprecated and not supported in .ACCDB file formats.

Constant

Description

dbEncrypt

Encrypt the database while compacting.

dbDecrypt

Decrypt the database while compacting.

If you omit an encryption constant or if you include both dbDecrypt and dbEncrypt, DstName will have the same encryption as SrcName.

You can use one of the following constants in the options argument to specify the version of the data format for the compacted database. This constant affects only the version of the data format of DstName and doesn't affect the version of any Microsoft Access-defined objects, such as forms and reports.

Constant

Description

dbVersion10

Creates a database that uses the Microsoft Jet database engine version 1.0 file format while compacting.

dbVersion11

Creates a database that uses the Microsoft Jet database engine version 1.1 file format while compacting.

dbVersion20

Creates a database that uses the Microsoft Jet database engine version 2.0 file format while compacting.

dbVersion30

Creates a database that uses the Microsoft Jet database engine version 3.0 file format (compatible with version 3.5) while compacting.

dbVersion40

Creates a database that uses the Microsoft Jet database engine version 4.0 file format while compacting.

dbVersion120

Creates a database that uses the Microsoft Access database engine version 12.0 file format while compacting.

You can specify only one version constant. If you omit a version constant, DstName will have the same version as SrcName. You can compact DstName only to a version that is the same or later than that of SrcName.

As you change data in a database, the database file can become fragmented and use more disk space than is necessary. Periodically, you can use the CompactDatabase method to compact your database to defragment the database file. The compacted database is usually smaller and often runs faster. You can also change the collating order, the encryption, or the version of the data format while you copy and compact the database.

You must close SrcName before you compact it. In a multiuser environment, other users can't have SrcName open while you're compacting it. If SrcName isn't closed or isn't available for exclusive use, an error occurs.

Because CompactDatabase creates a copy of the database, you must have enough disk space for both the original and the duplicate databases. The compact operation fails if there isn't enough disk space available. The DstName duplicate database doesn't have to be on the same disk as SrcName. After successfully compacting a database, you can delete the SrcName file and rename the compacted DstName file to the original file name.

The CompactDatabase method copies all the data and the security permission settings from the database specified by SrcName to the database specified by DstName.

Note

Because the CompactDatabase method doesn't convert Microsoft Access objects, you shouldn't use CompactDatabase to convert a database containing such objects.

Encrypted linked tables

Encrypted passwords are dependent on the file format of the database that you are using. If you are using an Access 2003 (.mdb) or earlier database, you will have one password to protect the database, and a separate password to encrypt the database. For Access 2007 (.accdb) and later (.mdb) databases, the only option is to encrypt and protect the database with one password, as the option to have two separate passwords has been removed.

Note

For Access 2007 (.accdb) databases, the password is the encryption key

You can use the following example VBA code for a command button:

    Private Sub Command0_Click()
    
    Dim strSourcePath As String
    Dim strDestPath As String
    
    strSourcePath = "<path>\sourceDb.accdb"
    strDestPath = "<path>\destDb.accdb"
    
    DBEngine.CompactDatabase strSourcePath, strDestPath, dbLangGeneral & ";pwd=Access", dbVersion120, ";pwd=Access"
    
    Set CurrentDatabase = CurrentDb
    Set LinkedTableDef = CurrentDatabase.CreateTableDef 
    ("My Linked Table")
    LinkedTableDef.Connect = "MS Access;pwd=Access";database=" & strDestPath
    LinkedTableDef.RefreshLink
    
    
    MsgBox "Finished"
    
    End Sub

The following code sample shows how to use CompactDatabase with a password (encryption key) and then link to a table in that compacted database. Note that a password must be supplied.

    Private Sub CompactAndLink_Click() 
     
    Dim strSourcePath As String
    Dim strDestPath As String
    Dim strSourceTableName As String
    Dim strDestTableName As String
    Dim tdf As TableDef
     
    strSourcePath = "<path>\<database>.accdb"
    strDestPath = "<path>\<database>.accdb"
    strSourceTableName = "<table name in destination database>"
    strDestTableName = "<linked table name>"
     
    ' Compact source database into new destination database with encrypted password
    DBEngine.CompactDatabase strSourcePath, strDestPath, dbLangGeneral & ";pwd=Access", dbVersion120, ";pwd=Access"
     
    ' Link to one of the tables in the destination database
    ' Password must be provided in the Connect property
     
    Set CurrentDatabase = CurrentDb
    Set tdf = CurrentDatabase.CreateTableDef(strDestTableName)
       
        With tdf
            .Connect = ";pwd=Access" & ";DATABASE=" & strDestPath
            .SourceTableName = strSourceTableName
        End With
        
    CurrentDatabase.TableDefs.Append tdf
     
    MsgBox "Database compacted and encrypted password applied. Link to table also completed."
     
    End Sub