Sql queries for updating a column
Specifies the temporary named result set or view, also known as common table expression (CTE), defined within the scope of the UPDATE statement.
The CTE result set is derived from a simple query and is referenced by UPDATE statement.
Table1 VALUES(1, 10.0), (1, 20.0); INSERT INTO dbo. 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. ) clause to perform a partial or full update of varchar(max), nvarchar(max), and varbinary(max) data types.
FROM Specifies that a table, view, or derived table source is used to provide the criteria for the update operation. If the object being updated is the same as the object in the FROM clause and there is only one reference to the object in the FROM clause, an object alias may or may not be specified.
If the object being updated appears more than one time in the FROM clause, one, and only one, reference to the object must not specify a table alias.
If the UPDATE statement affects multiple records, to return the old and new values for each record, use the OUTPUT clause. This can be configured in ODBC data sources or by setting connection attributes or properties.
The search condition can also be the condition upon which a join is based.The results of an UPDATE statement are undefined if the statement includes a FROM clause that is not specified in such a way that only one value is available for each column occurrence that is updated, that is if the UPDATE statement is not deterministic. 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 the column is being updated with NULL.For example, in the UPDATE statement in the following script, both rows in USE Adventure Works2012; GO IF OBJECT_ID ('dbo. To replace or modify large blocks of text, ntext, or image data, use WRITETEXT or UPDATETEXT instead of the UPDATE statement.Any characters not found in this code page are lost.DEFAULT Specifies that the default value defined for the column is to replace the existing value in the column.