IDalCommand.DescribeCursor

Syntax

DescribeCursor: IDalCursor;

Description

The DescribeCursor method creates a cursor, which contains only data fields. If there is an error in the text of the SQL query to the database, the exception is thrown. This method can be used to control the correctness of queries.

Example

Executing the example requires a form, a button with the Button1 identifier on the form and the Memo component with the Memo1 identifier. The repository must also contain a database with the DB identifier. This macro must be set as the OnClick event handler for the button.

Click the button to start executing the example.

Sub Button1OnClick(Sender: Object; Args: IMouseEventArgs);

Var

MB: IMetabase;

CrInf: IMetabaseObjectCreateInfo;

MObj: IMetabaseObject;

Query: IQuery;

DB_obj: IMetabaseObject;

DB_Inst: IDatabaseInstance;

DalComm: IDalCommand;

sql: String;

DalCur: IDalCursor;

Begin

MB := MetabaseClass.Active;

CrInf := Mb.CreateCreateInfo;

CrInf.ClassId := MetabaseObjectClass.KE_CLASS_QUERY;

CrInf.Id := "NEW_QUERY";

CrInf.Name := "NEW_QUERY";

CrInf.Parent := Mb.Root;

MObj := Mb.CreateObject(CrInf).Edit;

Query := MObj As IQuery;

DB_obj := Mb.ItemById("DB").Bind;

Query.Database := DB_obj As IDatabase;

sql := Memo1.Text;

Query.Sql := sql;

DB_Inst := DB_obj.Open(Null) As IDatabaseInstance;

DalComm := DB_Inst.Connection.CreateCommand(sql);

Try

DalCur := DalComm.DescribeCursor;

MObj.Save;

WinApplication.InformationBox("Query was created");

DalCur.Close;

Except

WinApplication.InformationBox("Query text contains error");

End Try;

DalComm.Close;

End Sub Button1OnClick;

After executing the example a query with the text specified in the Memo1 component is created in the repository. If there is an error in the query text, the information message is displayed. The query is not created.