The select-clause defines defines the structure of the query result. It has the following syntax:

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<selectClause> ::=
  Select <alias> [With(VersionInfoOnly)]
  | Select New [<targetIdentifier>] With { <memberDeclarator> [, <memberDeclarator>...] }

<memberDeclarator> ::=
  <memberAccess>
  | .<targetColumnIdentifier> = <expression>

<memberAccess> ::=
  <identifier>.<identifier>[.<identifier>...]
alias
Alias of the source entity as defined in the from-clause. The query's result will consist of instances of the type that is represented by the alias.
targetIdentifier
Name of the target entity. The target entity has to exist in time cockpit's metadata respository. The target identifier is optional. If you specify it the query's result will consist of instances of this type. If you do not specify it the result will consist of instances of a dynamically generated anonymous type.
memberAccess
Identifies a property or a relation of the source entity or of entities referenced by it.
targetColumnIdentifier
Name of the property in the dynamically generated anonymous result type.
expression
Expression that defines the result column. See TCQL Expression Language for details.
Anmerkung

The VersionInfoOnly-attribute can be used in scripts or applications that sync data from or into time cockpit. If you specify this attribute the TCQL runtime will not read any data except version information about the corresponding rows. This versioning data can be used to identify new, changed or deleted rows that may have to be included in a sync process.

Anmerkung
Keywords in TCQL are case sensitive. Therefore you have to write From, you cannot write from. Additionally identifiers have to start with a capital letter. Therefore you cannot write From p In Project.... Instead you have to write From P In Project... . This behavior may change in future versions of time cockpit so that TCQL may be case insensitive in the future.

Dieses Thema enthält die folgenden Abschnitte.

Beispiele

The following example shows a simple select-clause:

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// Return all Project entities
From P In Project Select P

The following example shows a select-clause resulting in a dynamically generated anonymous result type:

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From P In Project.Include('CustomerRelation')
Order By P.ProjectName, P.CustomerRelation.CustomerName Asc
Select New With
{
        P.ProjectName,
        P.CustomerRelation.CustomerName
}
Anmerkung

If the select-clause contains references to relations TCQL includes the referenced entities automatically. Therefore you need not explicitly add an Include element in the from-clause (see TCQL From Clause for details). However, you can add the include-clause explicitly if you want.

The following example shows a select-clause that creates a list of Project entities:

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From C In Customer
Select New Project With {
        .ProjectName = "Project " + C.CustomerName,
        .NumberOfHours = 0
}

Siehe auch