Szerkesztés

Megosztás a következőn keresztül:


ntext, text, and image (Transact-SQL)

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance

Fixed and variable-length data types for storing large non-Unicode and Unicode character and binary data. Unicode data uses the Unicode UCS-2 character set.

Important

The ntext, text, and image data types will be removed in a future version of SQL Server. Avoid using these data types in new development work, and plan to modify applications that currently use them. Use nvarchar(max), varchar(max), and varbinary(max) instead.

Arguments

ntext

Variable-length Unicode data with a maximum string length of 2^30 - 1 (1,073,741,823) bytes. Storage size, in bytes, is two times the string length that is entered. The ISO synonym for ntext is national text.

text

Variable-length non-Unicode data in the code page of the server and with a maximum string length of 2^31-1 (2,147,483,647). When the server code page uses double-byte characters, the storage is still 2,147,483,647 bytes. Depending on the character string, the storage size may be less than 2,147,483,647 bytes.

image

Variable-length binary data from 0 through 2^31-1 (2,147,483,647) bytes.

Remarks

The following functions and statements can be used with ntext, text, or image data.

Functions Statements
DATALENGTH READTEXT
PATINDEX SET TEXTSIZE
SUBSTRING UPDATETEXT
TEXTPTR WRITETEXT
TEXTVALID

Caution

When dropping columns using the deprecated ntext data type, the cleanup of the deleted data occurs as a serialized operation on all rows. The cleanup can require a large amount of time. When dropping an ntext column in a table with lots of rows, update the ntext column to NULL value first, then drop the column. You can run this option with parallel operations and make it much faster.

See also

Next steps