Concept explainers
SELECT statement: It is used to retrieve information from the table or
SELECT * FROM table_Name;
WHERE clause: “WHERE” statement is used limit the number of rows.
For example: Consider a table “FTable” that has two columns named “FruitName” and “Color”. “WHERE” clause is used when there is a need to display the entire FruitName whose color is Red.
SELECT * FROM FTable WHERE color = 'red';
When the above statement is executed, red colored fruits get displayed.
“COUNT()” function: In SQL, the “COUNT()” function will return the total number of rows in the table with satisfying the criteria mentioned in the “WHERE” clause.
GROUP BY Clause: The GROUPBY clause is used to group the result of a SELECT statement done on a table where the tuple values are similar for more than one column
Syntax:
SELECT expression1, expression2, expression_n, aggregate_function(expression)FROM table_name WHERE conditions GROUP BY expression1, expression2, expression_n;
ORDER BY Clause:
SQL contains “ORDER BY” clause in order to sort rows. The values get sorted in ascending as well as descending order. The keyword used to sort values in ascending order is “ASC” and for descending order is “DESC”. By default, it sorts values by ascending order.
Syntax:
SELECT column_Name1, column_Name2 FROM table_Name ORDER BY column_Name2;
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EBK DATABASE SYSTEMS: DESIGN, IMPLEMENT
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