11/19/2023 0 Comments Mysql union select syntax![]() Inside a table, a column often contains many duplicate values and sometimes you only want to list the different (distinct) values. So here using union we can get a record set of two select statements into a single record by selecting the columns and aliasing it for our advantage and using the WHERE clause to get a certain release year. The SELECT DISTINCT statement is used to return only distinct (different) values. The two SELECT statements must have the same number of columns and the the columns must have compatible data types. In a UNION query, there are at least two SELECT statements. Select show_id as id, show_title as title, initial_year as release_date from shows where initial_year <= 2000 Here are some rules that govern the way UNION operator is used in a query. So that's what we are gonna use so for this we will be using tables movies and shows so here's what they look like.Įxample select movie_id as id, movie_title as title,year as release_date from movies where year <= 2000 In our example, both the EmployeeUK and EmployeeUSA. In the following example we are retrieving all the values using the UNION ALL. MySQL UNION Operator Example: The following query combines two select statements using the UNION operator. Say I want a recordset of two tables with information about movie titles, id, and release year where the year of the release date should be less than or equal to 2000. Syntax of UNION ALL mysql> SELECT columnname FROM tablea UNION ALL SELECT columnname FROM tableb Where, columnname must be of same type and same order in both the SELECT statements. If you wanna a query recordset of tables with duplicate values too then UNION ALL is used. Syntax SELECT column names from TableName select from t1 union select from t2 intersect select from t3 order by c1 You can use parentheses () to change the calculation sequence of these operators. The respective columns should have similar data types too. ![]() ![]()
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