Is unique in SQL?

SQL UNIQUE Constraint. The UNIQUE constraint ensures that all values in a column are different. Both the UNIQUE and PRIMARY KEY constraints provide a guarantee for uniqueness for a column or set of columns. A PRIMARY KEY constraint automatically has a UNIQUE constraint.Click to see full answer. Likewise, is unique SQL query? Introduction to SQL Server SELECT DISTINCT clause table_name; The query returns only distinct values in the specified column. In other words, it removes the duplicate values in the column from the result set. In other words, the DISTINCT clause treats all NULL “values” as the same value.Furthermore, what is the difference between unique and distinct in SQL? Unique and Distinct are two SQL constraints. The main difference between Unique and Distinct in SQL is that Unique helps to ensure that all the values in a column are different while Distinct helps to remove all the duplicate records when retrieving the records from a table. Just so, how do I get unique records in SQL? SQL SELECT DISTINCT Statement SELECT DISTINCT returns only distinct (different) values. SELECT DISTINCT eliminates duplicate records from the results. DISTINCT can be used with aggregates: COUNT, AVG, MAX, etc. DISTINCT operates on a single column. DISTINCT for multiple columns is not supported. What is unique key in SQL with example?The UNIQUE Constraint prevents two records from having identical values in a particular column. In the CUSTOMERS table, for example, you might want to prevent two or more people from having identical age. Example: For example, the following SQL creates a new table called CUSTOMERS and adds five columns.