問題描述
這可能是一個(gè)菜鳥問題，但我發(fā)現(xiàn)了一些 T-SQL 查詢示例，可以使用 SELECT 和 WHERE 子句 驗(yàn)證數(shù)據(jù)庫(kù)大小.microsoft.com/en-us/library/ms176061.aspx" rel="nofollow">此處
It's maybe a noob question but I found some T-SQL query example to verify database size with SELECT and WHERE clause here
代碼如下:
SELECT name, size, size*1.0/128 AS [Size in MBs]
FROM sys.master_files
WHERE name = N'mytest';
我的問題是 WHERE name = N'keyword' 子句中的 N 前綴是什么意思?
My question is what does the N prefix mean in the WHERE name = N'keyword' clause?
我之前一直用WHERE name = 'keyword'，沒發(fā)現(xiàn)有什么不同(大家可以自己試一下).
I always use WHERE name = 'keyword' before, and I don't find the differences (you can try it by yourself).
我用谷歌搜索過，但我不知道我應(yīng)該搜索的關(guān)鍵字
I've googled that but I don't know the keyword I supposed to search
推薦答案
它將字符串聲明為 nvarchar 數(shù)據(jù)類型 (Unicode)，而不是 varchar(8 位編碼，包括 ASCII).
It's declaring the string as nvarchar data type (Unicode), rather than varchar (8-bit encoding, including ASCII).
僅供參考，這是問題的副本:前綴N是什么意思在 T-SQL 語句中?
FYI, this is a duplicate of the question: What is the meaning of the prefix N in T-SQL statements?
這篇關(guān)于字符串文字上的 SQL Server T-SQL N 前綴的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！