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Contents
Common Properties:
  Name *
Non-Visual Objects
  Action
  Collection
  Connection
  DataSource
  Head
  HTTP
  IniFile
  Message
  Query
    Active
    Connection
    Item
    Text
    Bof
    Bookmark
    ConnectionString
    Eof
    FieldCount
    FieldDefs
    Filter
    Filtered
    KeyField
    MaxRecords
    RecordCount
    Position
    RequestLive
    ParamCheck
    Params
    CachedUpdates
    ApplyUpdates
    CommitUpdates
    CancelUpdates
    RevertRecord
    UpdatesPending
    DeleteSQL
    InsertSQL
    ModifySQL
    UpdateParams
    ReadOnly
    MasterSource
    MasterFields
    RowsAffected
    SortedFields
    Lookup
    Locate
    Insert
    Delete
    Edit
    Cancel
    Post
    DisableControls
    EnableControls
    First
    Last
    Next
    Prior
    MoveBy
    Data
    Get
    PrimaryKey
    State
    OnScroll
    OnOpen
    OnClose
    OnPost
    OnInsert
    OnDelete
    Template
    StoredProc
    Exec
  Queue
  Registry
  Store
  Stream
  Template
  Thread
  Var
  XML
  XSL
Related Links:
  SQLStore
  DataSource
  Connection
  UpdateParams
  Active
  Bof
  ModifySQL
  Eof
  Filter
  ApplyUpdates
  CachedUpdates
  Params
  RequestLive
  ParamCheck
  InsertSQL
  Position
  DeleteSQL
  MasterSource
  MasterFields
  DisableControls
  EnableControls
  Data
  Get
  DataSource
Query [[zQuery]] 
NOTE: This Design document is subject to change at any time.
Query

Syntax: <QUERY property-list/>

Provides access to a database via Microsoft's ADO libraries. A Query should be associated with a particular Connection object that points to the actual database being accessed. Then the Text property is set to the SQL query that you wish to execute.

When used in the ZML layout file, a DataSource is used to point to the Query, and data-aware controls then point to the DataSource. zApp handles all of the internal database operations.

You can also create a Query object using the core.createobject("Query") method. Once the Connection and Text properties have been set, you can use the Open method to execute the query is and make the matching records available in the dataset. The Item property can then be used to retrieve or set values in the current record. Various other methods can be used to step through the records to manipulate the Dataset.

Example:

Using Dataset in the ZML file
Code:
<CONNECTION Name="MUDList" Filename="mudlist.mdb"/>
<QUERY Name="MUDData" Connection="MUDList"
  Text="SELECT * FROM mudlist WHERE Title LIKE 'a%'"/>
<DATASOURCE Name="MUDSource" Dataset="MUDData" Active="true"/>
<NAVIGATOR DataSource="MUDSource" Align="top"/>
<EDIT DataSource="MUDSource" Field="Title" Align="top"/>
<EDIT DataSource="MUDSource" Field="Host" Align="top"/>

This is a bit verbose, so zApp also allows to nest these objects and if the DataSource property of a control is missing, the last DataSource defined will be used. For example, the following code does the same thing as the previous example:
Code:
<CONNECTION Filename="mudlist.mdb">
  <QUERY Text="SELECT * FROM mudlist WHERE Title LIKE 'a%'">
    <DATASOURCE Name="MUDSource" Active="true"/>
  </QUERY>
</CONNECTION>
<NAVIGATOR Align="top"/>
<EDIT Field="Title" Align="top"/>
<EDIT Field="Host" Align="top"/>

Here is an example of using a Query object directly in a script.
Code:
Conn = core.AddControl("Connection", "MUDList")
Conn.Filename = "mudlist.mdb"
SQL = core.CreateObject( "Query", "MUDList")
SQL.Text = "SELECT * FROM mudlist WHERE Title LIKE 'a%'"
SQL.Open
Msgbox SQL.Item("Title")

Usage Tips

  • Remember that even when using the ZML layout, you need to activate your data connections somewhere. Typically you will need some sort of Script code like
    Code:
    DataSource.Active = true
    to make your datasource active and enable the data-aware controls that use the datasource. Or you can set the Active property in the <DATASOURCE> tag as we have done in these examples.
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