Introduction to Duplicate Rows in SQLite

Introduction to Duplicate Rows in SQLite

Duplicate rows refer to entries within a database table that share identical values across all columns or a subset of columns. These duplicates can arise due to various reasons, such as data entry errors, data migration issues, or database design problems....

Setting Up Environment

Let’s create a table called employees and insert some data also to better understand....

Identifying Duplicate Rows

Before start removing, it is important to identify which rows are duplicates. It can be done using SQLite’s GROUP BY and HAVING clauses in conjunction with aggregate functions like COUNT(). Let’s run basic query to identify duplicates in the employees table...

Ways to Removing Duplicate Rows

When an duplicates records are identified or verified then the next step to retain only one instance of each duplicated row and removing the others. SQLite offers multiple method to solve this which include help of ROWID, temporary tables, subqueries, and Common Table Expressions (CTEs). Let’s understand each one of them with the help of example....

Conclusion

Overall, After reading whole article now we have good understanding of how to identify duplicate rows and also how to delete them. We can remove duplicate rows with the help of one of them method which is described above. The method we have discussed which are ROWID, temporary tables, subqueries, and Common Table Expressions (CTEs). The Duplicate rows in database is important to remove to maintain data integrity and optimizing performance....