To find duplicate records, we can use a combination of GROUP BY and HAVING clause to check the count of records. Whenever the COUNT is greater than 1, it is a duplicate record. Here is an example for the same: SELECT name, email, COUNT(*) FROM customers GROUP BY name, email HAVING ...
Ans:In PostgreSQL, a predefined set of tables and indexes are stored in an area called the table space on the computer's file system. The same concept can be found in several other database management systems. Doing this enhances performance and security because each table has its own files ...
When indexes have been built on a column, these indexes are used to find all the matching rows for aWHEREclause, and then scanning happens through only those subsets of the data to discover the matches in the table. We can add an index in the following way: CREATEINDEXINDEX_EMAILONEMPLOYE...
Table: OrdersImage created by the author. We can find duplicate records is by using GROUP BY and HAVING clauseSyntaxSELECT order_id, customer_id, order_date, COUNT(*) as duplicate_count FROM orders GROUP BY order_id, customer_id, order_date HAVING COUNT(*) > 1...
Where clause, Group By clause, Having clause, Order By clause & Select.Read More 15 :: What is sql Synonyms? Synonyms is the alias name for table, views, sequences & procedures and are created for reasons of Security and Convenience.Two levels are Public - created by DBA & accessible to...
Aggregation functions are those that perform a mathematical operation on a result set. Some examples include AVG, COUNT, MIN, MAX, and SUM. Often, you’ll need GROUP BY and HAVING clauses to complement these aggregations. One useful aggregation function is AVG, which you can use to compute ...
WHERE Clause HAVING Clause It is used to filter out the records from a table on the basis of a specified condition. It is used to filter out the records from a group on the basis of a specified condition. We can use the WHERE clause without using the GROUP BY clause. Also, the WHERE...
Google Share on Facebook indirect question (redirected fromindirect questions) n (Grammar) a question reported in indirect speech, as inShe asked why you came. Comparedirect question Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 199...
Generally, aggregate functions are used in conjunction with GROUP BY or HAVING clauses. That separates the rows into groups or filters them to ensure relevancy, allowing you to limit the data points factored into the calculation.” 4. Tell me how you would store images in an Oracle database...
SQL (Structured Query Language)Aptitude Questions and Answers contain Aptitude Questions and Answers on Basic SQL, SQL Query Syntaxes, SQL Query Examples, Advance SQL with Join, Group By, Having Clauses. This section contains many Query Statements. ...