I have a management system, all CursorLocation ADOQUERY a component attribute is set to clUseClient, has been operating normally, I tried all Settings for clUseServer, system is not running, please help.

My way is:
1. Connect to the database, first set the ADOConnection CursorLocation to clUseServer
2. Call the form before, iterates through all ADOQUERY component form, and then set its CursorLocation to clUseServer

ADOQUERY. Open failure

CodePudding user response:

CursorLocation properties that specify the database pointer is pointing to the client or server, type TCursorLocation contains two values:
1, cluseServer: using server-side database pointer, applicable to the large amount of data data sets,
2, cluseClient: using client-side data pointer, the data will be downloaded to the local computer, and locally,
3, set CursorLocation:=cluseServer; Specify cursor, using the server terminal cursor has the advantage of using the server end, program to modify the database can be immediately reflected to the server, and other users to the operation of the database can also be reflected immediately, but brought high network traffic using the cursor on the server, each data access needs to exchange data through the network,
4, set CursorLocation:=cluseClient; Specified using client-side cursor, ADO provides the client cache data processing mechanism, therefore, ADO USES local data cache to reduce network traffic, although a loss on data access flexibility, but it greatly improves the performance of database access through the network,

Your software, using server-side database pointer, may use asynchronous retrieval multiple data sets, create network blocking,