How do you use the LEFT function (or an equivalent) on a SQL Server NTEXT column?
如何在SQL Server NTEXT列上使用LEFT函数(或等效函数)?
Basically I'm building a GridView and I just want to return the first 100 or so characters from the Description column which is NTEXT.
基本上我正在构建一个GridView,我只想返回描述列中的前100个字符,即NTEXT。
3 个解决方案
#1
8
SELECT CAST(ntext_col AS nvarchar(100)) as ntext_substr FROM ...
SELECT CAST(ntext_col AS nvarchar(100))as ntext_substr FROM ...
[EDIT] Originally had it returning LEFT(N,100) of CAST to nvarchar(MAX), CASTing will truncate and since LEFT is wanted, that is enough.
[编辑]最初让它将CAST的LEFT(N,100)返回到nvarchar(MAX),CASTing将截断,因为LEFT是需要的,这就足够了。
#2
3
You would have to cast it to a VARCHAR(MAX) first.
您必须首先将其强制转换为VARCHAR(MAX)。
#3
3
You can use the SUBSTRING function, which "returns part of a character, binary, text, or image expression":
您可以使用SUBSTRING函数,该函数“返回字符,二进制,文本或图像表达式的一部分”:
SUBSTRING ( value_expression , start_expression , length_expression )
So, to select the first 100 characters from your Description NTEXT column, you would use something like the following:
因此,要从描述NTEXT列中选择前100个字符,您将使用以下内容:
SELECT SUBSTRING(Description, 1, 100) as truncatedDescription FROM MyTable;
#1
8
SELECT CAST(ntext_col AS nvarchar(100)) as ntext_substr FROM ...
SELECT CAST(ntext_col AS nvarchar(100))as ntext_substr FROM ...
[EDIT] Originally had it returning LEFT(N,100) of CAST to nvarchar(MAX), CASTing will truncate and since LEFT is wanted, that is enough.
[编辑]最初让它将CAST的LEFT(N,100)返回到nvarchar(MAX),CASTing将截断,因为LEFT是需要的,这就足够了。
#2
3
You would have to cast it to a VARCHAR(MAX) first.
您必须首先将其强制转换为VARCHAR(MAX)。
#3
3
You can use the SUBSTRING function, which "returns part of a character, binary, text, or image expression":
您可以使用SUBSTRING函数,该函数“返回字符,二进制,文本或图像表达式的一部分”:
SUBSTRING ( value_expression , start_expression , length_expression )
So, to select the first 100 characters from your Description NTEXT column, you would use something like the following:
因此,要从描述NTEXT列中选择前100个字符,您将使用以下内容:
SELECT SUBSTRING(Description, 1, 100) as truncatedDescription FROM MyTable;