sql: select 空值问题
sql: select where problem with null value
学生table:
id name
0 NULL
1 John
查询:
SELECT * from students WHERE name != "John";
预期输出:
0 NULL
我的测试结果是空的,我该如何解决?
SELECT * from students WHERE name != "John" OR name == NULL;
学生table:
id name
0 NULL
1 John
查询:
SELECT * from students WHERE name != "John";
预期输出:
0 NULL
我的测试结果是空的,我该如何解决?
SELECT * from students WHERE name != "John" OR name == NULL;