Concept explainers
DISTINCTROW Keyword:
The “DISTINCTROW” keyword omits data based entire duplicate records, not like just duplicate fields. The syntax for “DISTINCT” keyword is as follows:
Syntax:
SELECT DISTINCTROWcol_Name FROM table_Name1 INNER JOIN table_Name2 ON table_Name1.col_Name = table_Name2.col_Name ORDER BY table_Name1;
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;
SUM function:
The “SUM” function is used to add the value and then return the sum of the expression in a “SELECT” statement.
Syntax:
SELECT SUM (exp) FROM table_Name [WHERE condition];
INNER JOIN keyword:
“INNER JOIN” keyword is used to select all the matching records of both the table.
Syntax:
SELECT col_Name FROM table_Name1 INNER JOIN table_Name2 ON table_Name1.col_Name = table_Name2.col_Name;
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Database Systems: Design, Implementation, & Management
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