How to combine/merge multiple queries in mysql?

by arnoldo.moen , in category: MySQL , 5 months ago

How to combine/merge multiple queries in mysql?

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1 answer

by cali_green , 3 months ago

@arnoldo.moen 

To combine or merge multiple queries in MySQL, you can use the UNION operator.


The UNION operator is used to combine the result sets of two or more SELECT statements into a single result set.


Here's an example of how to use UNION to merge multiple queries:

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SELECT column1, column2 FROM table1
UNION
SELECT column1, column2 FROM table2
UNION
SELECT column1, column2 FROM table3


In this example, we have three SELECT statements that select column1 and column2 from different tables. The UNION operator is used to combine the result sets of these three SELECT statements into a single result set.


Note that when using UNION, the columns selected in each SELECT statement must be of the same data type and in the same order. In case the column names are different in different SELECT statements, you can use aliases to make them consistent.