In SQL Server, the sp_describe_first_result_set system stored procedure returns the metadata for a result set.
More specifically, it returns the metadata for the first possible result set of a T-SQL batch.
It accepts three parameters, the first of which is the T-SQL statement/s you’re analysing.
Continue readingIn SQL Server, a batch is a group of one or more T-SQL statements sent at the same time from an application to SQL Server for execution.
If you encounter an error like this:
Msg 111, Level 15, State 1, Line 2
'CREATE VIEW' must be the first statement in a query batch.It’s probably because you’re combining the statement with other statements in the same batch, which is not allowed in batches.
The first part of the error message will depend on the actual statement that you’re using in your batch. In my case it’s CREATE VIEW, but it could just as easily be CREATE PROCEDURE, CREATE FUNCTION, etc if those are the statements you’re using.
When you compress a partitioned table in SQL Server, you can compress all partitions, some, or just one partition.
To do this, use the REBUILD PARTITION syntax within the ALTER TABLE statement.
When doing this, you can rebuild just the specified partition or all partitions. Alternatively, you can rebuild all partitions, while compressing only a specific partition or list of partitions.
Continue readingWhen you create a table in SQL Server, you have the option of using data compression.
Data compression helps reduce the size of the database. It can also help improve performance of I/O intensive workloads due to the data being stored in fewer pages, therefore reducing the number of pages that queries need to read from disk.
To do this, use the DATA_COMPRESSION option when creating the table.
You can use the ALTER TABLE statement to enable compression on an existing table in SQL Server.
To do this, you need to use the REBUILD WITH option, while specifying your desired compression type.
SQL Server has a system stored procedure called sp_estimate_data_compression_savings, which allows you to check an object’s size and its estimated size with various levels of compression.
If the object is already compressed, you can use this procedure to estimate its size when recompressed.
Objects can be compressed by using row, page, columnstore or columnstore archive compression.
Compression can be evaluated for whole tables or parts of tables. This includes heaps, clustered indexes, nonclustered indexes, columnstore indexes, indexed views, and table and index partitions.
Continue readingSQL Server’s Database Mail has a stored procedure called sp_send_dbmail that you can use to send emails from SQL Server.
You can use this stored procedure to send query results formatted into an HTML table.
Continue readingWhen you use the sp_send_dbmail stored procedure to email the results of a query, the column headers are included by default.
You can include or exclude the column headers with the @query_result_header argument. To remove the column headers, use @query_result_header = 0.
Error message 110 is a commonly encountered error in SQL Server when inserting data into a table. The full error looks like this:
Msg 110, Level 15, State 1, Line 1 There are fewer columns in the INSERT statement than values specified in the VALUES clause. The number of values in the VALUES clause must match the number of columns specified in the INSERT statement.
This happens when you specify less columns in the INSERT statement than the number of values that you’re trying to insert with the VALUES clause.
This will occur if you accidentally omit one or more columns from the INSERT statement.
You’d get a similar (but technically different) error if you tried to do the opposite – specify more columns in the INSERT statement than you try to insert.
In SQL Server, you can create DML triggers that execute code only when a specific column is updated.
The trigger still fires, but you can test whether or not a specific column was updated, and then run code only if that column was updated.
You can do this by using the UPDATE() function inside your trigger. This function accepts the column name as its argument. It returns a boolean.