/// <summary>
/// Executes a Query in the Database, synchronously only.
/// </summary>
/// <param name="credentialOptions">Object with data necessary to access the Linkar Server: Username, Password, EntryPoint, Language, FreeText.</param>
/// <param name="filename">Name of file on which the operation is performed. For example LK.ORDERS</param>
/// <param name="selectClause">Statement fragment specifies the selection condition. For example WITH CUSTOMER = '1'</param>
/// <param name="sortClause">Statement fragment specifies the selection order. If there is a selection rule, Linkar will execute a SSELECT, otherwise Linkar will execute a SELECT. For example BY CUSTOMER</param>
/// <param name="dictClause">Space-delimited list of dictionaries to read. If this list is not set, all fields are returned. For example CUSTOMER DATE ITEM. You may use the format LKFLDx where x is the attribute number.</param>
/// <param name="preSelectClause">An optional command that executes before the main Select</param>
/// <param name="selectOptions">Object with options to manage how records are selected, including calculated, dictionaries, conversion, formatSpec, originalRecords, onlyItemId, pagination, regPage, numPage.</param>
/// <param name="outputFormat">Indicates in what format you want to receive the data resulting from the Read, New, Update and Select operations: MV, XML, XML_DICT, XML_SCH, JSON, JSON_DICT or JSON_SCH.</param>
/// <param name="customVars">Free text sent to the database allows management of additional behaviours in SUB.LK.MAIN.CONTROL.CUSTOM, which is called when this parameter is set.</param>
/// <param name="receiveTimeout">Maximum time in seconds that the client will wait for a response from the server. Default = 0 to wait indefinitely.</param>
/// <returns>The results of the operation.</returns>
/// <remarks>
/// In the preSelectClause argument these operations can be carried out before executing the Select statement:
/// <list type="bullet">
/// <item>Previously call to a saved list with the GET.LIST command to use it in the Main Select input</item>
/// <item>Make a previous Select to use the result as the Main Select input, with the SELECT or SSELECT commands.In this case the entire sentence must be indicated in the PreselectClause. For example:SSELECT LK.ORDERS WITH CUSTOMER = '1'</item>
/// <item>Exploit a Main File index to use the result as a Main Select input, with the SELECTINDEX command. The syntax for all the databases is SELECTINDEX index.name.value. For example SELECTINDEX ITEM,"101691"</item>
/// </list>
/// </remarks>
public static string Select(CredentialOptions credentialOptions, string filename, string selectClause = "", string sortClause = "", string dictClause = "", string preSelectClause = "", SelectOptions selectOptions = null,
DATAFORMATCRU_TYPE outputFormat = DATAFORMATCRU_TYPE.MV,
string customVars = "", int receiveTimeout = 0)
{
string selectArgs = OperationArguments.GetSelectArgs(filename, selectClause, sortClause, dictClause, preSelectClause, selectOptions, customVars);
byte opCode = (byte)OPERATION_CODE.SELECT;
byte byteInputFormat = (byte)DATAFORMAT_TYPE.MV;
byte byteOutputFormat = (byte)outputFormat;
string result = Linkar.ExecuteDirectOperation(credentialOptions, opCode, selectArgs, byteInputFormat, byteOutputFormat, receiveTimeout);
return(result);
}