database - How to select unique records by SQL - Stack Overflow
With the distinct keyword with single and multiple column names, you get distinct records: SELECT DISTINCT column 1, column 2, ... FROM table_name;
SQL SELECT DISTINCT Statement - W3Schools
The SELECT DISTINCT statement is used to return only distinct (different) values. Select all the different countries from the "Customers" table: Inside a table, a column often contains many duplicate values; and sometimes you only want to list the different (distinct) values. SELECT DISTINCT column1, column2, ...
sql server - SQL: How do I SELECT only the rows with a unique …
2015年5月5日 · SELECT distinct contract, activity from @t a WHERE (SELECT COUNT(DISTINCT activity) FROM @t b WHERE b.contract = a.contract) = 1 And here's another one -- shorter/cleaner without subquery. select contract, max(activity) from @t group by contract having count(distinct activity) = 1
SQL Server SELECT DISTINCT
This tutorial shows you how to use the SQL Server SELECT DISTINCT clause to retrieve the only distinct values in a specified list of columns.
What’s the Difference Between UNIQUE and DISTINCT in SQL?
2021年5月20日 · Despite the words unique and distinct being synonyms, they cover very different things in SQL. The UNIQUE keyword in SQL plays the role of a database constraint; it ensures there are no duplicate values stored in a particular column or a set of columns.
SELECT DISTINCT SQL Command Examples - MSSQLTips.com - SQL …
2023年2月23日 · Learn about the SELECT DISTINCT SQL command to return a unique list of values from SELECT queries along with several examples.
How to Use DISTINCT in SQL - LearnSQL.com
Master using the DISTINCT in SQL with our tutorial. Learn to remove duplicates from your query results effectively.
How to Use the DISTINCT Clause in SQL - Database.Guide
2023年10月21日 · We use the DISTINCT keyword to return only unique rows. It eliminates duplicates from the results. If we have two or more rows with exactly the same data, we’ll only see one row in the results.
SQL DISTINCT: A Detailed Guide With Examples
In SQL, the DISTINCT keyword is used in the SELECT statement to eliminate duplicate rows from the result set, allowing only unique values to be displayed. The UNIQUE keyword is a constraint applied to a table column that ensures that all values in …
How to Use Select Distinct in SQL: A Simple Guide for Efficient ...
2023年9月24日 · If you’re not familiar already, SELECT DISTINCT is a handy tool in our SQL arsenal that helps to return unique values within a database column. Here’s how we can use it in its simplest form: SELECT DISTINCT column_name FROM table_name;
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