If you have a partitioned table or index in SQL Server, and you want to determine which partition a given value would be mapped to, you can do this nice and quickly with the $PARTITION system function.
All you need to know is the name of the partition function (and of course, the value you’re interested in).
Continue readingIf you’ve previously created a partitioned table in SQL Server, and you now want to know how many rows are being stored in each partition, here are three queries you can use.
In particular, you can:
sys.dm_db_partition_stats viewsys.partitions view$PARTITION function in a queryBelow are examples of all three.
Continue readingThe SQL CREATE TABLE ... AS SELECT statement enables you to insert the results of a query into a new table.
The SQL SELECT INTO statement is a Sybase extension that can be used to insert the results of a query into a table (or a variable, depending on the DBMS).
The SQL INSERT statement is most commonly used to insert individual rows into a table.
But you can also insert the results of a query into a table. This means that you can insert multiple rows at once (as long as they’re returned by the query).
Continue readingSQL Server has the UPDATE() function that you can use within your DML triggers to check whether or not a specific column has been updated.
While this function only accepts one column, there’s nothing to stop you from including multiple UPDATE() clauses with AND or OR to test for multiple column updates.
In SQL Server, you can query the sys.partitions system catalog view to find out whether or not a partition has been compressed.
In particular, the data_compression column tells you whether it’s compressed or not. The data_compression_desc column tells you what type of compression it uses. If it isn’t compressed, it returns NONE.
A SQL join is where you run a query that joins multiple tables.
This SQL joins tutorial presents basic examples of SQL joins, as well as an introduction to the various join types.
Continue readingThis article contains examples of basic SQL queries that beginners can use to retrieve data from their databases.
Continue readingThis article contains basic SQL DELETE statements that beginners can use to delete data from their database tables.