Linux SQL statement Concise tutorial---UNION all

The purpose of the UNION all directive is to merge the results of the two SQL statements together. the union All and union differ in that union all lists each qualifying material, regardless of whether the data value is duplicated or not.

The syntax for UNION All is as follows:

[SQL Statement 1]
UNION All
[SQL statement 2];

We use the same example as the previous page to show the difference between union All and union . Also assume that we have the following two tables,

store_information Form

Store_name	Sales	Txn_date
Los Angeles	1500	05-jan-1999
San Diego	250	07-jan-1999
Los Angeles	300	08-jan-1999
Boston	700	08-jan-1999

Internet Sales table

Txn_date	Sales
07-jan-1999	250
10-jan-1999	33s
11-jan-1999	320
12-jan-1999	750

And we need to find out the days of store turnover and network turnover. To achieve this, we use the following SQL statement:

SELECT txn_date from Store_information
UNION All
SELECT txn_date from Internet_sales;

Results:

Txn_date

jan-05-1999

jan-07-1999

jan-08-1999

jan-08-1999

jan-07-1999

jan-10-1999

jan-11-1999

jan-12-1999

Linux is measured as follows:

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Linux SQL statement Concise tutorial---UNION all