faramarz_s
شنبه 27 دی 1382, 21:45 عصر
در مورد چند سطر زیر بزرگواری توضیح می دهد؟
If an update query could alter more than one row while updating both the clustering key and one or more text, image, or Unicode columns, the update operation fails and SQL Server returns an error message.
Modifying a text, ntext, or image column with UPDATE initializes the column, assigns a valid text pointer to it, and allocates at least one data page unless updating the column with NULL.
Note The UPDATE statement is logged. If you are replacing or modifying large blocks of text, ntext, or image data, use the WRITETEXT or UPDATETEXT statement instead of the UPDATE statement. The WRITETEXT and UPDATETEXT statements (by default) are not logged.
If an update query could alter more than one row while updating both the clustering key and one or more text, image, or Unicode columns, the update operation fails and SQL Server returns an error message.
Modifying a text, ntext, or image column with UPDATE initializes the column, assigns a valid text pointer to it, and allocates at least one data page unless updating the column with NULL.
Note The UPDATE statement is logged. If you are replacing or modifying large blocks of text, ntext, or image data, use the WRITETEXT or UPDATETEXT statement instead of the UPDATE statement. The WRITETEXT and UPDATETEXT statements (by default) are not logged.