Example Code :
public static server str ReleasePostingDate() { return SysComputedColumn::if( SysComputedColumn::isNullExpression(SysComputedColumn::returnField( tableStr(TIDAPUninvoiceConsignmentItem) , identifierStr(LedgerJournalTableRealease), fieldStr(LedgerJournalTable, PostedDateTime))), SysComputedColumn::cast(strFmt("'%1'",DateTimeUtil::date(DateTimeUtil::maxValue())),'NVARCHAR'), SysComputedColumn::cast(SysComputedColumn::returnField( tableStr(TIDAPUninvoiceConsignmentItem) , identifierStr(LedgerJournalTableRealease), fieldStr(LedgerJournalTable, PostedDateTime)),'NVARCHAR') ); }