Read Tables from SAP R/3 using SAP.NET Connector（C#）
|
|
||
IntroductionUsing SAP's .NET Connector is very easy, all it takes to manage it is a little work and effort. This article provides you an introductory example on how to use the Connector within C#.
The example will teach you:
Any GUI stuff is omitted to keep the example as simple as possible and to focus on the Connector's use. BackgroundYou should have some experiences with ABAP/4 and function modules and the SAP.NET Connector installed. Any project that uses the Connector must have a reference to Using the codeIf you want to use
If you want to see how it works, download and unzip the demo file to disk. Either run DBReaderDemo.exe in the bin subfolder of the demo project from console directly, or open DBReaderDemo.sln into Visual Studio and run the demo. The SELECT TABNAME, TABCLASS
FROM DD02L
WHERE TABNAME LIKE 'NP%'
AND ( TABCLASS EQ 'TRANSP' OR
TABCLASS EQ 'CLUSTER' OR
TABCLASS EQ 'POOL' OR
TABCLASS EQ 'VIEW' )
The equivalent code to achieve this with  Collapse public void demoTableReader(){
// Show the available destinations and let the user select one.
string destName = this.askForDestination();
if(destName == null)
return;
// Get the selected destination object.
SAP.Connector.Destination dest = this.saplogon.getDestinationByName(
destName);
Console.WriteLine("Connecting to '" + destName + "'");
// Information like system number, SAPServer etc. are already
// obtained by the .Net Connector from the c:\windows\saplogon.ini file.
// It remains to add these information:
dest.Client = 1;
Console.Write("User: ");
dest.Username = Console.ReadLine();
Console.Write("Password: ");
dest.Password = Console.ReadLine();
dest.Language = "EN";
// Setup the TableReader
SAPReader.TableReader tabReader = new TableReader(dest);
// Specify the table to read.
// The table DD02L contains metadata of all the available
// tables on a SAP system.
tabReader.QueryTable = "DD02L";
// How many rows of the table should be skipped.
tabReader.RowSkip = 10;
// How many rows should be selected (at most, if available).
tabReader.RowCount = 6;
// Yes, we want to see data.
// Default is NoData=true, i.e., only table information is retrieved.
tabReader.NoData = false;
// Select FOI (fields of interest)
SAPReader.SAPKernel.RFC_DB_FLD tabNameField =
tabReader.addQueryField("TABNAME");
SAPReader.SAPKernel.RFC_DB_FLD tabClassField =
tabReader.addQueryField("TABCLASS");
//
// Add the WHERE clause
string pattern = "NP%";
// Select the names of all the transparent, cluster, pool
// and view tables containing the pattern:
tabReader.addWhereClause("TABNAME LIKE '" + pattern + "'");
tabReader.addWhereClause("AND ( TABCLASS EQ 'TRANSP' OR");
tabReader.addWhereClause(" TABCLASS EQ 'CLUSTER' OR");
tabReader.addWhereClause(" TABCLASS EQ 'POOL' OR");
tabReader.addWhereClause(" TABCLASS EQ 'VIEW' )");
// Force to read the table from SAP
string abapException = tabReader.read();
if(abapException == null){
// Output the result:
SAPReader.ResultSet RS = tabReader.getResultSet();
Console.WriteLine("\n\nTableData read:");
Console.WriteLine(tabNameField.Fieldname + "\t\t" +
tabClassField.Fieldname);
Console.WriteLine(
"-----------------------------------------------------");
for(int i = 0; i < RS.LineCount; i++){
Console.Write(RS.getEntryAt(tabNameField.Fieldname, i).Trim());
Console.Write("\t\t" +
RS.getEntryAt(tabClassField.Fieldname, i).Trim());
Console.WriteLine();
}
}
else{
Console.WriteLine("ABAP-Exception: " + abapException );
}
// That's it!
}
After the table was read successfully, the Points of InterestThe fragmented screenshot below shows the console output for this example.
The Collapse public SAP.Connector.Destination getDestinationByName(string name){
// Map the name used for displaying the available destination,
// e.g. at SAPLogon, to the internal name used to address this item.
// BTW, the internal name (key) is derived from saplogon.ini.
string destName = this.GetDestinationNameFromPrintName(name);
// null returned if the destination does not exist.
if(destName == null || destName == "" ){
Console.WriteLine(this.GetType().ToString()
+ ".getDestinationByName: Destination " + name +
" does not exist."
);
Console.WriteLine("Available Destinations are: ");
this.printAvailableDestinations(Console.Out);
Environment.Exit(0);
}
// This is the key statement for selecting the
// desired destination item:
this.DestinationName = destName;
// Now all information is retrieved from the SAPLogon's ini file
// to the respective variables of 'this' destination object.
// (The ini file is stored in the private variable:
// SAP.Connector.SAPLogonDestination.saplogon.fileName)
return (SAP.Connector.Destination)this;
}
The RFC call is performed by Collapse public string read(){
if(this.proxy.connected() == false){
this.proxy.connectSAP();
}
try {
// Force the proxy to make the rfc call synchronously
// See documentation for RFC_READ_TABLE Function Module at
// your SAP system for further details (Transaction SE37).
this.proxy.SAPProxy.Rfc_Read_Table(this.delim, this.noData,
this.qTable, this.rowCount, this.rowSkip,
ref this.data, ref this.fields, ref this.options);
// Check if data found
if( this.NoData == false && this.data.Count == 0 ){
return "No data found";
}
// NoData set
if(this.NoData == true){
for( int i = 0; i < this.fields.Count; i++){
this.results.addEntry(this.fields[i], "NoData");
}
}
// NoData not set
// Save data to the column-wise ResultSet.
else if(this.data.Count > 0 ){
//Loop over data rows
for( int i = 0; i < this.data.Count; i++){
//Loop over fields
for(int j = 0; j < this.fields.Count; j++){
string val = this.parseTableRow(this.fields[j], this.data[i]);
this.results.addEntry(this.fields[j], val);
}
}
}//else
}
catch (SAP.Connector.RfcSystemException ex) {
System.Text.StringBuilder msg = new System.Text.StringBuilder();
msg.Append("Table: " + this.qTable);
foreach(SAPKernel.RFC_DB_FLD field in this.fields){
msg.Append("\nFields: " + field.Fieldname);
}
foreach(SAPKernel.RFC_DB_OPT opt in this.options){
msg.Append("\nOptions: " + opt.Text);
}
Console.WriteLine(msg + "\n"
+ "Error calling SAP RFC \n" + ex.ToString() + "\n" + ex.ErrorCode,
"Problem with SAP"
);
return ex.ErrorCode;
}
catch(SAP.Connector.RfcAbapException ex){
return ex.ErrorCode;
}
return null;
}
Data returned by the RFC call is stored row-wise. A value of a field in a certain row can be extracted by using the offset and length stored in each field structure returned: Collapse public string parseTableRow(SAPReader.SAPKernel.RFC_DB_FLD field,
SAPReader.SAPKernel.TAB512 dataRow ){
// Length of the field
int len = int.Parse(field.Length);
// Position where the field's value starts in the data row
int offset = int.Parse(field.Offset);
// The data row, containing all the field values concatenated
// by SAP's rfc_read_table
string row = dataRow.Wa;
string retValue = "";
try{
if(offset < row.Length){
// Read the field's value starting at the position specified
// by offset.
if(offset + len > row.Length)
// Read until the end of the row string
retValue = dataRow.Wa.Substring(offset);
else
// Read only len characters, otherwise.
retValue = dataRow.Wa.Substring(offset,len);
}
}catch(System.ArgumentOutOfRangeException e){
Console.WriteLine(e.ToString());
Environment.Exit(0);
}
return retValue;
}
|
