Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>I'll explain the complete scenario using <strong>AdventureWorks</strong> database for <strong>SQL Server 2008 R2</strong>. I'll also assume that you've already placed the <code>TSQLConnection</code> component and properly set its parameters to established connection with your database. For this example, I'll also assume the name for it to be <strong>Conn1</strong>.</p> <p>On a form, place 2 <code>TSQLTable</code> (named <strong>tableA</strong> and <strong>tableB</strong>), 2 <code>TDataSetProvider</code> (named <strong>dspA</strong> and <strong>dspB</strong>), 2 <code>TClientDataSet</code> (named <strong>cdsA</strong> and <strong>cdsB</strong>), 2 <code>TDataSource</code> (named <strong>dsA</strong> and <strong>dsB</strong>) and 2 <code>TDBGrid</code> (named <strong>gridA</strong> and <strong>gridB</strong>) components.</p> <p>Set properties as follows:</p> <pre><code>tableA.SQLConnection = Conn1 tableA.SchemaName = Sales tableA.TableName = Customer tableA.Active = True dspA.DataSet = tableA cdsA.ProviderName = dspA cdsA.Active = True dsA.DataSet = cdsA gridA.DataSource = dsA tableB.SQLConnection = Conn1 tableB.SchemaName = Sales tableB.TableName = SalesOrderHeader tableB.Active = True dspB.DataSet = tableB cdsB.ProviderName = dspB cdsB.MasterSource = cdsA cdsB.MasterFields = CustomerID cdsB.Active = True dsB.DataSet = cdsB gridB.DataSource = dsB </code></pre> <p>In <strong>gridA</strong> you should see all <strong>Customers</strong>, and in <strong>gridB</strong> you should see only <strong>Orders</strong> related to curently selected customer.</p> <p>This is the basic example of establishing master/detail relationship between two TClientDataSet components in Delphi. However, there are other ways to do this.</p>
    singulars
    1. This table or related slice is empty.
    1. PODelphi7, dbExpress and Master Detail relationship
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USLightBulb
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COI think the problem stay in the query. Using dbExpress I must specify the foreing key field in the query's column set, not only in it's where clause. Is this true? If (as I hope) not what did I miss?
      singulars
      1. PO
      1. USFrancesco
    2. CONo, you don't have to do that. I'd advise you start a new project and recreate what I've explained. That may help you to fully understand how to properly establish master/detail relations in Delphi. Also, take a look at the database itself. The structure of tables may help you to further understand how foreign keys work and may point you to possible problem in design of your database.
      singulars
      1. PO
      1. USLightBulb
    3. COIf I don't specify a `IndexFieldNames` value I get a `field index out of range`. If `TabA JOIN TabB on a = b`, I must specify `b` as value for detail's `IndexFieldNames` property. If not the grid does not show anything. I work on Vista, Delphi7, Oracle11g, Devart dbExpress driver (version 4.70).
      singulars
      1. PO
      1. USFrancesco
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload