Can we apply distinct on two columns?

Can we apply distinct on two columns?

Answer. Yes, the DISTINCT clause can be applied to any valid SELECT query. It is important to note that DISTINCT will filter out all rows that are not unique in terms of all selected columns.

How do you get the distinct combination of two columns in SQL?

If you want distinct values from only two fields, plus return other fields with them, then the other fields must have some kind of aggregation on them (sum, min, max, etc.), and the two columns you want distinct must appear in the group by clause.

How do I select two columns from two different tables in SQL?

Let’s see the example for the select from multiple tables: SELECT orders. order_id, suppliers.name. FROM suppliers….Example syntax to select from multiple tables:

1. SELECT p. p_id, p. cus_id, p.
2. FROM product AS p.
3. LEFT JOIN customer1 AS c1.
4. ON p. cus_id=c1.
5. LEFT JOIN customer2 AS c2.
6. ON p. cus_id = c2.

How do I get unique combinations in SQL?

When more than one expression is provided in the DISTINCT clause, the query will retrieve unique combinations for the expressions listed. In SQL, the DISTINCT clause doesn’t ignore NULL values. So when using the DISTINCT clause in your SQL statement, your result set will include NULL as a distinct value.

Does distinct in SQL apply to all columns?

Yes, DISTINCT works on all combinations of column values for all columns in the SELECT clause.

How can I get different columns in two tables in MySQL?

“how to select multiple columns from different tables in mysql” Code Answer

1. — MySQL.
2. — t1 = table1.
3. — dt2 = column of table.
4. SELECT t1. dt2, t2. dt4, t2. dt5, t2. dt3 #get dt3 data from table2.
5. FROM table1 t1, table2 t2 — Doesn’t need to have t1, or t2.
6. WHERE t1. dt2 = ‘asd’ AND t2. dt4 = ‘qax’ AND t2. dt5 = 456.
7. ​

How do I join two columns of different tables in MySQL?

However, if you want to join two different columns of two different tables into a single column without WHERE then you can do like: SELECT CONCAT( table1. col1 , table2. col2) AS colName FROM Table table1,Table table2.

Is distinct or group by better?

Group by is expensive than Distinct since Group by does a sort on the result while distinct avoids it. But if you want to make group by yield the same result as distinct give order by null ..

How to use distinct SQL?

Database:

Operators:

Problem: You’d like to query your data to return the result without duplicate rows.

Example: Our database has a table named books with data in the columns author_firstname,author_lastname,and book_title.

Solution: We’ll use the DISTINCT clause.

How do you sort columns in SQL?

You can sort by multiple columns by stating each column in the ORDER BY clause, separating each column name with a comma. SQL will first order the results by the first column, then the second, and so on for as many columns that are included in the ORDER BY clause.

How to compare two columns in SQL Server?

You can use COMPUTED COLUMN. Of course this is if you can modify table structure and if you will do that comparison very often. Inside the COMPUTED COLUMN you can calculate if all columns that you need to compare contains the same data with boolean value. After that you only compare that value in your queries.

What does select distinct mean in SQL?

The SQL SELECT DISTINCT Statement. The SELECT DISTINCT statement is used to return only distinct (different) values. Inside a table, a column often contains many duplicate values; and sometimes you only want to list the different (distinct) values.