Sql updating table definition
The fields in a view are fields from one or more real tables in the database.You can add SQL functions, WHERE, and JOIN statements to a view and present the data as if the data were coming from one single table.Modifying the data type of a column that already contains data can result in the permanent loss of data when the existing data is converted to the new type.In addition, code and applications that depend on the modified column may fail.Many times, however, it is more efficient to use a set-based approach to create new rows.
A view contains rows and columns, just like a real table.When you modify the data type of a column, Table Designer applies the default length of the data type you selected, even if you have already specified another.Always set the data type length for to the desired value after specifying the data type.We recommend not updating statistics too frequently because there is a performance tradeoff between improving query plans and the time it takes to recompile queries. UPDATE STATISTICS can use tempdb to sort the sample of rows for building statistics.Transact-SQL Syntax Conventions -- Syntax for SQL Server and Azure SQL Database UPDATE STATISTICS table_or_indexed_view_name [ ] [ WITH [ FULLSCAN [ [ , ] PERSIST_SAMPLE_PERCENT = ] | SAMPLE number [ [ , ] PERSIST_SAMPLE_PERCENT = ] | RESAMPLE [ ON PARTITIONS ( [, …n] ) ] | is not specified, the query optimizer updates all statistics for the table or indexed view.
Specifies the temporary named result set or view, also known as common table expression (CTE), defined within the scope of the UPDATE statement.