What does `Type: IP (0x0800)` in the Ethernet II part of a ping packet mean?
The "Type" field in Ethernet II frames tells the OS what kind of data the frame carries – 0x0800 means that the frame has an IPv4 packet; there's a list of different EtherTypes.
This field is needed because there are many other protocols that go directly over Ethernet: for example, IPv6, IPX, ARP, AppleTalk...
This is explained in detail in the Wikipedia article about Ethernet frames, in particular the section about Ethernet frame types – Ethernet II ("DIX") frames have a "Type" field, but some networks (in particular the now-obsolete IPX) used to use IEEE 802.3 framing, which has "Packet size" instead, and uses separate 'LLC' (802.2) or even 'LLC'+'SNAP' headers between Ethernet header and protocol data.
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mohamed faisal
Updated on September 18, 2022Comments
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mohamed faisal almost 2 years
I have a two tables called 1.ReportTableDetails and 2.SecurityDetails
ReportTableDetails
ReportName | ColumnNames | FilterNames -------------------------------------- Total Sales | data1,data2 | data1,data2 Branch Sales | data1,data2 | data1,data2
SecurityDetails
SecurityLevel | ReportName | RColumn | RFilter -------------------------------------------------------- 1 | Total Sales | data1,data2 | data1,data2 4 | Total Sales | data1,data2 | data1,data2
I will search the records by
SecurityLevel from SecurityDetails
. The condition is, if the ReportName is not found in SecurityDetails, it should pick the data from ReportTableDetailsExpecting output
SecurityLevel | ReportName | RColumnNames| RFilterNames | ColumnNames | FilterNames --------------------------------------------------------------------------------------- 1 | Total Sales | data1,data2 | data1,data2 | | 1 | Branch Sales | | | data1,data2 | data1,data2
What I tried is inner join with SecurityDetails table. it retrieves when the report names are equal. But i want to retrieve which is not in SecurityDetails table also
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Dan Bracuk over 7 yearsA combination of outer join and isNull() should work.
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mohamed faisal over 7 years@DanBracuk can you show me some sample code?
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Yashveer Singh over 7 years@mohamedfaisal I answered but I have some question with our output I mentione din my answer that as well
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Arjan about 8 years@grawity, a bit late, but nice how you edited your answer in here! :-) (Will delete this comment soon.)
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mohamed faisal over 7 yearsActually when i execute your query, it's retrieving only one row, which is equal the report name from both table
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SqlZim over 7 years@mohamedfaisal Then you probably changed the query to use
where sd.SecurityLevel = @SecurityLevel
instead of leaving it as a join condition. Check the rextester link, it proves the query works for the provided test data. rextester.com/QGZHLO98381 -
mohamed faisal over 7 yearssorry. its working fine. But i don't want the columname and filternames values of first row record
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SqlZim over 7 years@mohamedfaisal Updated to return empty strings when
SecurityDetails
has column and filter values.