How many main clauses are there in SQL?

Which program represents the MySQL server?

The following statement is valid.

SELECT abc, xyz FROM table1 UNION abc, def FROM table2;

If the following keyword is used with UNION, then duplicate rows are retained.

To measure the length of a string in bytes, the operator used is _________ 

 What is abc in the following statement? 

DELETE FROM xyz WHERE abc = 11;

A [_____] column allocates a string with a variable amount of space depending on the data length that is actually stored.

 Which character set variable indicates the character set used for storing identifiers?
 

What column names are displayed when this command is executed?

 SHOW COLUMNS FROM tbl_name LIKE '%name';   

  What is the meaning of the “WHERE” clause in Mysql?