1 week Ago
SQL is a language used to get data from databases. It helps websites, apps, and reports work. Even social media and online shopping use SQL behind the scenes.
The basic rules are easy to learn. But a few smart tricks can make SQL faster, neater, and more useful. Here are six simple SQL tricks that help write better queries.
There are tables or columns with lengthy names. Repeating them every time is time-consuming and makes queries difficult to read. Aliases are shortened names that replace longer ones.
This keeps things tidy and easy to read, particularly in large queries with lots of tables. At times, one might need to display custom labels in a query . Scores can be converted to "Pass" or "Fail" as an example.
CASE statements assist in adding such logic. They test conditions and output other values depending on the information. It's an easy method to sort out results without modifying the original table.
Some tables contain thousands of rows. All of them can be slow to load. LIMIT only returns a limited number of rows.
OFFSET skips some rows before displaying the rest. They are useful in displaying data in small pieces, such as 10 items per time on a webpage. Data is usually stored in multiple tables.
Joins are what pull that data together. An inner join displays just corresponding rows from both tables. A left join displays all in exactly the first table, and matches in the second.
A right join displays all in the second table. Selecting the correct join ensures the query displays the correct data. Sometimes it’s better to group data than to see each row.
For example, to find out how much each customer spent, group orders by customer. Then total the amounts. GROUP BY helps find sums, averages, and counts.
This is useful for reports, dashboards, and data summaries. Some rows have missing data. These show up as NULL.
If left alone, they can cause confusion or errors. COALESCE replaces NULL with a backup value. For example, if a phone number is missing , the query can show Not Given instead.
This keeps the results clear. These six tricks make SQL easier to use. They help clean up messy queries, speed up results, and improve reports.
Whether learning SQL for school or using it for work, these tips help turn basic queries into smart ones..
