要在数据库中查找学生名字，可以使用SQL SELECT语句，从特定的表中筛选出学生名字列，并通过条件子句过滤所需的数据。以下是一些常用的方法：
查找所有学生名字
```sql
SELECT student_name FROM students;
```
根据学生的姓名进行查找
```sql
SELECT * FROM students WHERE name = '张三';
```
根据学生的学号进行查找
```sql
SELECT * FROM students WHERE student_id = 1001;
```
使用LIKE关键字进行模糊匹配
```sql
SELECT * FROM students WHERE name LIKE '刘%';
```
联合多个表通过JOIN操作获取数据
```sql
SELECT students.name
FROM students
JOIN classes ON students.student_id = classes.student_id
WHERE classes.class_name = '计算机科学';
```
查询同名学生的信息
```sql
SELECT * FROM students WHERE name IN (SELECT name FROM students GROUP BY name HAVING COUNT(name) > 1);
```
查询姓刘或姓李的学生情况
```sql
SELECT * FROM students WHERE name LIKE '刘%' OR name LIKE '李%';
```
查询所有选修过课程的学生学号（不重复）
```sql
SELECT DISTINCT student_id FROM student_courses;
```
查询考试不及格的学生学号（不重复）
```sql
SELECT DISTINCT student_id FROM scores WHERE grade = 18;
```
查询年龄在18-20岁（包括18岁和20岁）之间的学生的姓名和年龄
```sql
SELECT name, age FROM students WHERE age BETWEEN 18 AND 20;
```
查询所有女学生的姓名和出生年份
```sql
SELECT name, birth_year FROM students WHERE gender = '女';
```
查询通信系和计算机系学生的姓名和性别
```sql
SELECT name, gender FROM students WHERE department IN ('通信系', '计算机系');
```
查询既不是通信系也不是计算机系的学生的姓名和性别
```sql
SELECT name, gender FROM students WHERE department NOT IN ('通信系', '计算机系');
```
查询所有姓张的学生的姓名、学号和性别
```sql
SELECT student_id, name, gender FROM students WHERE name LIKE '张%';
```
查询全名为两个汉字的学生的姓名
```sql
SELECT name FROM students WHERE LENGTH(name) = 2;
```
查询所有不姓张的学生的姓名
```sql
SELECT name FROM students WHERE name NOT LIKE '张%';
```
查询名字中第2个字为“无”字的学生的姓名和学号
```sql
SELECT student_id, name FROM students WHERE name LIKE '_无%';
```
这些方法涵盖了从基本查询到复杂查询的多种场景，可以根据具体需求选择合适的查询方式。