如何在MySQL中删除空白行？
使用delete命令删除MySQL中的空白行。
语法如下
delete from yourTableName where yourColumnName=' ' OR yourColumnName IS NULL;
上面的语法将删除空白行和NULL行。
为了理解这个概念，让我们创建一个表。创建表的查询如下
mysql> create table deleteRowDemo -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> StudentName varchar(20) -> );
使用insert命令在表中插入一些记录。
查询如下
mysql> insert into deleteRowDemo(StudentName) values('John');
mysql> insert into deleteRowDemo(StudentName) values('');
mysql> insert into deleteRowDemo(StudentName) values('');
mysql> insert into deleteRowDemo(StudentName) values(NULL);
mysql> insert into deleteRowDemo(StudentName) values('Carol');
mysql> insert into deleteRowDemo(StudentName) values('Bob');
mysql> insert into deleteRowDemo(StudentName) values('');
mysql> insert into deleteRowDemo(StudentName) values('David');使用select语句显示表中的所有记录。
查询如下
mysql> select *from deleteRowDemo;
以下是输出
+----+-------------+ | Id | StudentName | +----+-------------+ | 1 | John | | 2 | | | 3 | | | 4 | NULL | | 5 | Carol | | 6 | Bob | | 7 | | | 8 | David | +----+-------------+ 8 rows in set (0.00 sec)
这是删除空白行以及NULL的查询
mysql> delete from deleteRowDemo where StudentName='' OR StudentName IS NULL;
现在，让我们再次检查表记录。
查询如下
mysql> select *from deleteRowDemo;
以下是输出
+----+-------------+ | Id | StudentName | +----+-------------+ | 1 | John | | 5 | Carol | | 6 | Bob | | 8 | David | +----+-------------+ 4 rows in set (0.00 sec)