procedure GetRowColumn(const ColumnName: String; Params: TParams;
       var ContentType: String; var Data: TBytes; const DatabaseName:
      String='')

procedure GetRowColumn(Request: TEWBWebServerRequest; const
      ColumnName: String; var ContentType: String; var Data: TBytes;
      const DatabaseName: String='')

Usage

Use this method to retrieve the a BLOB column for the dataset as a raw string (byte per character with no translation).

When this method is called, the dataset adapter will:

• Trigger the OnGetSelectColumnParams event handler to get a list of parameters for the Select<Column> dataset command (where <Column> is the ColumnName parameter being passed into this method).



• Trigger the OnExecuteSelectColumn event handler to execute the Select<Column> dataset command. The TDataSet instance that is used for retrieving the BLOB column is returned in this event handler.

There are two versions of this method: one for Elevate Web Builder server module applications and one for non-Elevate Web Builder server module applications such as ISAPI modules.

• For Elevate Web Builder server module applications, the Request parameter indicates the incoming web server request, and is used to retrieve any incoming parameters that should be used when executing the Select dataset command, the ColumnName parameter is the name of the BLOB column to retrieve, and the DatabaseName parameter is a pass-through parameter that is passed to any event handlers in order to indicate that the operation is occurring for a specific database.



• For non-Elevate Web Builder server module applications, the Params parameter indicates the incoming parameters that should be used when executing the Select dataset command, the ColumnName parameter is the name of the BLOB column to retrieve, and the DatabaseName parameter is a pass-through parameter that is passed to any event handlers in order to indicate that the operation is occurring for a specific database.

If the dataset contains a column called <Column>_ContentType, then the value of that column will be returned in the variable ContentType parameter and should indicate the MIME type of the BLOB column for the row that matches the incoming request parameters.

Please see the Web Server Database Access API topic under the Using the Web Server section in the Elevate Web Builder manual for more information on how BLOB column access is performed.