Updating table with values from another table
TOP ( ) Specifies one or more table hints that are allowed for a target table. @ Note When referencing the Unicode character data types nchar, nvarchar, and ntext, 'expression' should be prefixed with the capital letter 'N'.If 'N' is not specified, SQL Server converts the string to the code page that corresponds to the default collation of the database or column.Common table expressions can also be used with the SELECT, INSERT, DELETE, and CREATE VIEW statements.For more information, see WITH common_table_expression (Transact-SQL). For information about table hints, see Table Hints (Transact-SQL).All other references to the object in the FROM clause must include an object alias. Table1 (c1 int PRIMARY KEY NOT NULL, c2 int NOT NULL); GO CREATE TABLE dbo. Table2 WHERE CURRENT OF abc; GO SELECT c1, c2 FROM dbo.A view with an INSTEAD OF UPDATE trigger cannot be a target of an UPDATE with a FROM clause. Table2 (d1 int PRIMARY KEY NOT NULL, d2 int NOT NULL); GO INSERT INTO dbo. Table2 VALUES (1, 20), (2, 30); GO DECLARE abc CURSOR LOCAL FOR SELECT c1, c2 FROM dbo. Table1; GO Support for use of the READUNCOMMITTED and NOLOCK hints in the FROM clause that apply to the target table of an UPDATE or DELETE statement will be removed in a future version of SQL Server.
A positioned update using a WHERE CURRENT OF clause updates the single row at the current position of the cursor. To replace or modify large blocks of text, ntext, or image data, use WRITETEXT or UPDATETEXT instead of the UPDATE statement.
Note Any call to OPENDATASOURCE, OPENQUERY, or OPENROWSET in the FROM clause is evaluated separately and independently from any call to these functions used as the target of the update, even if identical arguments are supplied to the two calls. Avoid using these hints in this context in new development work, and plan to modify applications that currently use them.
In particular, filter or join conditions applied on the result of one of those calls have no effect on the results of the other. Table2; USE Adventure Works2012; GO IF OBJECT_ID ('dbo. All char and nchar columns are right-padded to the defined length.
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.