Sql-concat (string join function)

Sometimes, we need to concatenate the data obtained from different fields. Each database provides a way to achieve this:

• Mysql:concat ()
• Oracle:concat (), | |
• SQL Server: +

The syntax for CONCAT () is as follows:

CONCAT (String 1, String 2, String 3, ...): concatenates strings 1, Strings 2, strings 3, and so on.

Please note that Oracle's concat () only allows two parameters;

In other words, you can concatenate only two strings at a time. However, in Oracle, we can use the ' | | ' To concatenate multiple strings at once.

Take a look at some examples. Suppose we have the following table:

Geography form

Region_name	Store_name
East	Boston
East	New York
West	Los Angeles
West	San Diego

Example 1:

mysql/oracle:
SELECT CONCAT (region_name,store_name) from Geography
WHERE store_name = ' Boston ';

Results :

' Eastboston '

Example 2:

Oracle:
SELECT Region_name | | "| | Store_name from Geography
WHERE store_name = ' Boston ';

Results :

' East Boston '

Example 3:

SQL Server:
SELECT region_name + "+ store_name from Geography
WHERE store_name = ' Boston ';

Results :

' East Boston '

Transferred from: http://blog.sina.com.cn/s/blog_4b93170a0100biyp.html

Sql-concat (string join function)