What does UNION do?What is the difference between UNION and UNION ALL?
UNION merges the contents of two structurally compatible tables into single combined table.The difference between UNION and UNION ALL is that UNION will omit duplicate records whereas UNION ALL will include duplicate records. It is important to notice that the performance of UNION ALL will typically be better than UNION Because UNION requires the server to do additional work by removing any duplicates.
How do you indicate the character set being used by an HTML 5 document?How does this differ from older HTML standards?
In HTML 5,the encoding used can be indicated with the charset attribute of a <meta>tag inside the document's <head> element. <!DOCTYPE html> <html> <head> ..... <meta charset="UTF-8"> ---- </head> ---- </html> Where as in HTML 4.01 document would use the <meta> tag as follows,it doesn't have charset attribute: <!DOCTYPE> <html> <head> ..... <meta http-equiv="Content-Type"> ---- </head> </html>
What are namespaces, and how they are used?
Namespaces are used to organize classes within .NET Framework.They dictate the logical structure of the code.They are analogous to Java Packages, with the key difference being Java packages define the physical layout of source files, While .NET namespaces do not.However, many developers follow this approach and organize their C# source files in directories that correlate with a namespace.