Updating a table in sql
Use the @@ROWCOUNT function to return the number of inserted rows to the client application. If ANSI_PADDING is set to OFF, all trailing spaces are removed from data inserted into varchar and nvarchar columns, except in strings that contain only spaces. If ANSI_PADDING is set to ON, trailing spaces are inserted.For more information, see @@ROWCOUNT (Transact-SQL). Variable names can be used in UPDATE statements to show the old and new values affected, but this should be used only when the UPDATE statement affects a single record. The Microsoft SQL Server ODBC driver and OLE DB Provider for SQL Server automatically set ANSI_PADDING ON for each connection.This can also be used to change the column to NULL if the column has no default and is defined to allow null values.Compound assignment operator: = Add and assign -= Subtract and assign *= Multiply and assign /= Divide and assign %= Modulo and assign &= Bitwise AND and assign ^= Bitwise XOR and assign |= Bitwise OR and assign Returns updated data or expressions based on it as part of the UPDATE operation.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.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).
After each exercise, we provide the solution so you can check your answer.
UPDATE summary_data SET current_category = (SELECT category_id FROM products WHERE products.product_id = summary_data.product_id) WHERE EXISTS (SELECT category_id FROM products WHERE products.product_id = summary_data.product_id); If you want to test your skills using the SQL UPDATE statement, try some of our practice exercises.
These exercises allow you to try out your skills with the UPDATE statement.
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.The SQL UPDATE Query is used to modify the existing records in a table.