我們可以在一個 MySQL 查詢中使用 WHERE、AND 和 OR 嗎?
是的,我們可以在一個查詢中使用它們。首先,讓我們建立一個表——
mysql> create table DemoTable ( StudentId int, StudentFirstName varchar(20), StudentLastName varchar(20), StudentAge int ); Query OK, 0 rows affected (0.53 sec)
使用插入命令向表中插入記錄——
mysql> insert into DemoTable values(100,'John','Smith',23); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(101,'Carol','Taylor',24); Query OK, 1 row affected (0.62 sec) mysql> insert into DemoTable values(103,'John','Doe',22); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable values(104,'Adam','Smith',23); Query OK, 1 row affected (0.18 sec)
使用選擇語句顯示錶中的所有記錄——
mysql> select *from DemoTable;
這將產生以下輸出——
+-----------+------------------+-----------------+------------+ | StudentId | StudentFirstName | StudentLastName | StudentAge | +-----------+------------------+-----------------+------------+ | 100 | John | Smith | 23 | | 101 | Carol | Taylor | 24 | | 103 | John | Doe | 22 | | 104 | Adam | Smith | 23 | +-----------+------------------+-----------------+------------+ 4 rows in set (0.00 sec)
以下是使用 MySQL WHERE、AND 和 OR 在一個 MySQL 查詢中獲取記錄的查詢——
mysql> select *from DemoTable where StudentFirstName='John' AND StudentLastName='Doe' OR StudentAge=26;
這將產生以下輸出——
+-----------+------------------+-----------------+------------+ | StudentId | StudentFirstName | StudentLastName | StudentAge | +-----------+------------------+-----------------+------------+ | 103 | John | Doe | 22 | +-----------+------------------+-----------------+------------+ 1 row in set (0.00 sec)
廣告
資料結構
網路
RDBMS
作業系統
Java
iOS
HTML
CSS
Android
Python
C 程式設計
C++
C#
MongoDB
MySQL
Javascript
PHP