在 MySQL 中获取字段值小于 5 个字符的行?


要获取字段值小于 5 个字符的行,你需要使用 LENGTH() 函数。语法如下 −

SELECT *FROM yourTableName WHERE LENGTH(yourColumnName) < 5;

为了理解上述语法,让我们创建一个表。创建表的查询如下 −

mysql> create table fieldLessThan5Chars
   -> (
   -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   -> yourZipCode varchar(10)
   -> );
Query OK, 0 rows affected (0.52 sec)

现在你可以使用插入命令在表中插入一些记录。查询如下 −

mysql> insert into fieldLessThan5Chars(yourZipCode) values('35801');
Query OK, 1 row affected (0.10 sec)
mysql> insert into fieldLessThan5Chars(yourZipCode) values('3580');
Query OK, 1 row affected (0.20 sec)
mysql> insert into fieldLessThan5Chars(yourZipCode) values('90001');
Query OK, 1 row affected (0.40 sec)
mysql> insert into fieldLessThan5Chars(yourZipCode) values('100');
Query OK, 1 row affected (0.20 sec)
mysql> insert into fieldLessThan5Chars(yourZipCode) values('10');
Query OK, 1 row affected (0.17 sec)
mysql> insert into fieldLessThan5Chars(yourZipCode) values('0');
Query OK, 1 row affected (0.15 sec)
mysql> insert into fieldLessThan5Chars(yourZipCode) values('90209');
Query OK, 1 row affected (0.11 sec)
mysql> insert into fieldLessThan5Chars(yourZipCode) values('33124');
Query OK, 1 row affected (0.20 sec)

使用 select 语句显示表中的所有记录。查询如下 −

mysql> select *from fieldLessThan5Chars;

以下是输出 −

+----+-------------+
| Id | yourZipCode |
+----+-------------+
|  1 | 35801       |
|  2 | 3580        |
|  3 | 90001       |
|  4 | 100         |
|  5 | 10          |
|  6 | 0           |
|  7 | 90209       |
|  8 | 33124       |
+----+-------------+
8 rows in set (0.00 sec)

示例

下面是获取字段值小于 5 个字符的所有行的查询 −

mysql> select *from fieldLessThan5Chars where length(yourZipCode) < 5;

输出

+----+-------------+
| Id | yourZipCode |
+----+-------------+
|  2 |        3580 |
|  4 |         100 |
|  5 |          10 |
|  6 |           0 |
+----+-------------+
4 rows in set (0.00 sec)

更新于:2020-06-26

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