如何从 MySQL 中的 SELECT 查询中获取特定列记录?
让我们首先创建一个表 -
mysql> create table DemoTable1837 ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentName varchar(20) ); Query OK, 0 rows affected (0.00 sec)
使用 insert 命令向表中插入一些记录 -
mysql> insert into DemoTable1837(StudentName) values('Chris'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1837(StudentName) values('David'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1837(StudentName) values('Bob'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1837(StudentName) values('Mike'); Query OK, 1 row affected (0.00 sec)
使用 select 语句从表中显示所有记录 -
mysql> select * from DemoTable1837;
这将产生以下输出 -
+-----------+-------------+ | StudentId | StudentName | +-----------+-------------+ | 1 | Chris | | 2 | David | | 3 | Bob | | 4 | Mike | +-----------+-------------+ 4 rows in set (0.00 sec)
以下是获取特定列记录的查询
mysql> select StudentName from DemoTable1837;
这将产生以下输出 -
+-------------+ | StudentName | +-------------+ | Chris | | David | | Bob | | Mike | +-------------+ 4 rows in set (0.00 sec)
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