MariaDB Calculated Fields

MariaDB Calculated Fields

合并查询列

(jlive)[crashcourse]>SELECT Concat(RTrim(vend_name), ' (', RTrim(vend_country), ')') AS vend_title FROM vendors ORDER BY vend_title;

+-------------------------+

| vend_title              |

+-------------------------+

| ACME (USA)              |

| Anvils R Us (USA)       |

| Furball Inc. (USA)      |

| Jet Set (England)       |

| Jouets Et Ours (France) |

| LT Supplies (USA)       |

+-------------------------+

6 rows in set (0.01 sec)

数学计算

MariaDB Mathematical Operators

--------------------------------

Operator Description

--------------------------------

+ Addition       

- Subtraction

* Multiplication

/ Division

 

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(jlive)[crashcourse]>SELECT prod_id, LTrim(quantity), LTrim(item_price), LTrim(quantity*item_price) AS expanded_price FROM orderitems WHERE order_num = 20005;

+---------+-----------------+-------------------+----------------+

| prod_id | LTrim(quantity) | LTrim(item_price) | expanded_price |

+---------+-----------------+-------------------+----------------+

| ANV01   | 10              | 5.99              | 59.90          |

| ANV02   | 3               | 9.99              | 29.97          |

| TNT2    | 5               | 10.00             | 50.00          |

| FB      | 1               | 10.00             | 10.00          |

+---------+-----------------+-------------------+----------------+

 

4 rows in set (0.01 sec)