sql怎么转long
时间: 2024-09-06 15:06:03 浏览: 29
在SQL中,将字符串或者其他非数值类型转换为`LONG`类型(通常是整数类型,如bigint)通常涉及类型转换函数。具体的语法可能会因数据库系统而异,但以下是一些常见情况下的示例:
**MySQL:**
```sql
SELECT CAST(str_column AS BIGINT) AS long_value
FROM table_name;
```
在这里,`str_column`是你想要转换的列名,`BIGINT`是目标类型。
**PostgreSQL:**
```sql
SELECT CAST(str_column AS BIGINT) AS long_value
FROM table_name;
```
语法类似,只是关键字不同。
**Oracle:**
```sql
SELECT TO_NUMBER(str_column) AS long_value
FROM table_name;
```
`TO_NUMBER`函数可以解析字符串并转换为数字。
**SQL Server:**
```sql
SELECT TRY_CAST(str_column AS BIGINT) AS long_value
FROM table_name;
```
`TRY_CAST`会尝试转换,如果失败则返回NULL。
注意,如果字符串无法被解析为一个有效的长整型数字(例如含有非数字字符),上述转化可能会失败,并抛出错误。所以在转换之前,最好先验证输入数据的有效性。
相关问题
my sql longtext
MySQL `LONGTEXT` is a data type that allows you to store large amounts of text data, up to 4GB in size. It is often used to store large amounts of unstructured data such as text documents, blog posts, or even binary data such as images.
Here is an example of how to define a `LONGTEXT` column in a MySQL table:
```
CREATE TABLE my_table (
id INT PRIMARY KEY,
my_long_text LONGTEXT
);
```
You can then insert large amounts of text data into the `my_long_text` column using an `INSERT` statement:
```
INSERT INTO my_table (id, my_long_text)
VALUES (1, 'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed non risus. Suspendisse lectus tortor, dignissim sit amet, adipiscing nec, ultricies sed, dolor.');
```
You can also query the `LONGTEXT` column using a `SELECT` statement:
```
SELECT my_long_text FROM my_table WHERE id = 1;
```
sql里面ip地址转long型
可以通过MySQL内置的INET_ATON和INET_NTOA函数来实现IP地址和长整型之间的转换。
将IP地址转换为长整型:
SELECT INET_ATON('192.168.0.1');
将长整型转换为IP地址:
SELECT INET_NTOA(3232235521);
其中,3232235521是ip地址192.168.0.1转化为长整型的结果。
注意:在MySQL中,存储IP地址时可以使用int(10) UNSIGNED类型,用于存储转换后的长整型。
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