How to combine two query sets in MySQL?

How to combine two query sets in MySQL?

SELECT column_list UNION [ DISTINCT | ALL ] SELECT column_list UNION [ DISTINCT | ALL ] SELECT column_list To combine result set of two or more queries using the UNION operator, these are the basic rules that you must follow: First, the number and the orders of columns that appear in all SELECT statements must be the same.

What happens when you Union two rows in MySQL?

Because the rows with value 2 and 3 are duplicates, the UNION removed them and kept only unique values. The following Venn diagram illustrates the union of two result sets that come from t1 and t2 tables: If you use the UNION ALL explicitly, the duplicate rows, if available, remain in the result.

Is it possible to combine two tables without a common column?

Yes, you can! The longer answer is yes, there are a few ways to combine two tables without a common column, including CROSS JOIN (Cartesian product) and UNION. The latter is technically not a join but can be handy for merging tables in SQL.

Can you add a column to a MySQL Query?

To differentiate between employees and customers, you can add a column as shown in the following query: MySQL also provides you with an alternative option to sort a result set based on column position using ORDER BY clause as follows: However, it is not a good practice to sort the result set by column position.

How to combine unrelated queries to one row in SQL?

Old question, but where others use JOIN to combine unrelated queries to rows in one table, this is my solution to combine unrelated queries to one row, e.g: (which tells me that our web server currently uses 14 Oracle sessions out of the total of 290 sessions; I log this output without headers in an sqlplus script that runs every so many minutes)

How to sort the result of a Union in MySQL?

MySQL UNION and ORDER BY. If you want to sort the result set of a union, you use an ORDER BY clause in the last SELECT statement as shown in the following example: ORDER BY fullname; Notice that if you place the ORDER BY clause in each SELECT statement, it will not affect the order of the rows in the final result set.