Microsoft KB Archive/176830

= How To Create a Connection Programmatically =

Article ID: 176830

Article Last Modified on 3/11/2005

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APPLIES TO


 * Microsoft Visual FoxPro 3.0 Standard Edition
 * Microsoft Visual FoxPro 3.0b Standard Edition
 * Microsoft Visual FoxPro 5.0 Standard Edition
 * Microsoft Visual FoxPro 5.0a
 * Microsoft Visual FoxPro 6.0 Professional Edition
 * Microsoft Visual FoxPro 3.0b for Macintosh
 * Microsoft Data Access Components 2.5

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This article was previously published under Q176830



SUMMARY
Under some circumstances, you may need to modify the properties of a connection at run time. This article describes each of the properties and the default values of a connection. The sample code illustrates how to create a connection and use the DBSETPROP function to set the properties of a connection programmatically.



MORE INFORMATION
The following table indicates the data types and default values associated with each of the properties of a connection.   Property       Connection Designer Label    Data Type   Default Value -

DispLogin       Display Login               Numeric        1 Asynchronous    Asynchronous Execution      Logical        .F.   DispWarnings     Display Warnings            Logical        .F.   BatchMode        Batch Processing            Logical        .T.   Transactions     Automatic Transactions      Numeric        1 PacketSize      Packet Size                 Numeric        4096 Comment                                     Character      '' ConnectTimeOut  Connection (sec)            Numeric        15 IdleTimeOut     Idle (min)                  Numeric        3 QueryTimeOut    Query (sec)                 Numeric        3 WaitTime        Wait Time (ms)              Numeric        100 The sample code below creates and modifies the properties of a connection:

Note You must change Username= and PWD= to the correct values before you run this code. Make sure that Username has the appropriate permissions to perform this operation on the database. *Begin code LOCAL lcconnstring, lcconname, lnconnections, lbconnexists lcconnstring   =  "'DSN=PUBS;DATABASE=pubs;Username= ;PWD= ;'" lcconnname     =   "VFPCONN" lnconnections  =   0 lbconnexists   =   .F.   IF !FILE('VFPCONN.DBC') CLOSE DATA ALL CREATE DATABASE VFPCONN ELSE OPEN DATABASE VFPCONN ENDIF lnconnections=ADBOBJECTS(CONNECTS,'CONNECTION') IF lnconnections>0 FOR i=1 TO ALEN(CONNECTS,1) IF UPPER(CONNECTS[i])=lcconnname lbconnexists=.T.  EXIT ENDIF NEXT ENDIF IF !lbconnexists CREATE CONNECTION &lcconnname CONNSTRING (lcconnstring) ENDIF * Set connection properties to custom values. =DBSETPROP('VFPCONN','Connection','DispLogin', 3) =DBSETPROP('VFPCONN','Connection','Asynchronous', .T.) =DBSETPROP('VFPCONN','Connection','DispWarnings', .T.) =DBSETPROP('VFPCONN','Connection','BatchMode', .F.) =DBSETPROP('VFPCONN','Connection','Transactions', 2) =DBSETPROP('VFPCONN','Connection','PacketSize',8192) =DBSETPROP('VFPCONN','Connection','Comment', 'Comment Added') =DBSETPROP('VFPCONN','Connection','ConnectTimeOut', 10) =DBSETPROP('VFPCONN','Connection','IdleTimeOut', 0) =DBSETPROP('VFPCONN','Connection','QueryTimeOut', 0) =DBSETPROP('VFPCONN','Connection','WaitTime',150) MODI CONNECTION VFPCONN RETURN *End code. After running the program code, a dialog appears titled "Connection Designer-VPFCONN." Click the Verify Connection button and a message indicating the connection was successful should appear.

NOTE: In order to use the connection, an ODBC Data source matching the Data source name specified in the connection string must exist.

If the ODBC Data source does not exist, the following ODBC error message is returned:

Connectivity error [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified.

