In SQL, the OR operator allows you to use alternative conditions when filtering your queries.
The OR operator combines two conditions, and returns TRUE when either of the conditions is TRUE.
SQL EXISTS Operator for Beginners
In SQL, the EXISTS operator specifies a subquery to test for the existence of rows. It returns TRUE when the subquery returns one or more rows.
A subquery is a query that is nested inside another query (or even another subquery)
This article contains some basic examples of the EXISTS operator.
SQL CREATE TABLE … AS SELECT Statement
The SQL CREATE TABLE ... AS SELECT statement enables you to insert the results of a query into a new table.
SQL INSERT INTO… SELECT Examples
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).
Execute a Trigger Only When Certain Columns are Updated (SQL Server)
SQL 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.
Find Out if a Partition is Compressed in SQL Server (T-SQL)
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.
How to Fix “The select list for the INSERT statement contains fewer items than the insert list”
SQL Server error 120 occurs when you don’t specify enough columns in your INSERT list when using a SELECT list for the values to insert.
To be more specific, it happens when you use a SELECT list in your INSERT statement, but the SELECT list doesn’t return as many columns as you’re specifying with the INSERT.
This is easy to fix. Simply make sure the number of columns match between your INSERT and SELECT list.