Database.Guide – Page 298

How to Fix “Conversion failed when converting the value to data type” in SQL Server

December 4, 2020 by Ian

SQL Server error Msg 245, Level 16 tells us that there was a problem when trying to convert a value to a specific data type.

You’ll get this error if you try to insert the wrong data type into a column.

To fix this issue, make sure the data type of the value you’re trying to insert, matches the column’s type.

3 Ways to Return the Number of Rows in Each Partition in SQL Server (T-SQL)

December 3, 2020 by Ian

If 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:

Query the sys.dm_db_partition_stats view
Query the sys.partitions view
Use the $PARTITION function in a query

Below are examples of all three.

SQL Greater Than (>) Operator for Beginners

December 3, 2020 by Ian

In SQL, the greater than operator (>) compares two expressions and returns TRUE if the left operand has a value higher than the right operand; otherwise, it returns FALSE.

SQL Greater Than or Equal To (>=) Operator for Beginners

December 3, 2020 by Ian

In SQL, the greater than or equal to operator (>=) compares two expressions and returns TRUE if the left operand has a value greater than or equal to the right operand; otherwise, it returns FALSE.

SQL Less Than or Equal To (<=) Operator for Beginners

December 2, 2020December 2, 2020 by Ian

In SQL, the less than or equal to operator (<=) compares two expressions and returns TRUE if the left operand has a value lower than or equal to the right operand; otherwise, the result is FALSE.

You can use it to determine whether a value is less than or equal to another value.

SQL Less Than (<) Operator for Beginners

December 2, 2020December 2, 2020 by Ian

In SQL, the less than operator (<) compares two expressions and returns TRUE if the left operand has a value lower than the right operand; otherwise, the result is FALSE.

SQL Not Equal To (<>) Operator for Beginners

December 2, 2020 by Ian

In SQL, the not equal to operator (<>) compares the non-equality of two expressions. That is, it tests whether one expression is not equal to another expression.

If either or both operands are NULL, NULL is returned.

SQL also has another not equal to operator (!=), which does the same thing. Which one you use may depend on your DBMS, which one you’re the most comfortable using, and perhaps also whether your organisation has any coding conventions that dictate which one should be used.

SQL Not Equal To (!=) Operator for Beginners

February 11, 2022December 2, 2020 by Ian

In SQL, the not equal to operator (!=) compares the non-equality of two expressions. That is, it tests whether one expression is not equal to another expression.

If either or both operands are NULL, NULL is returned.

SQL also has another not equal to operator (<>), which does the same thing. Which one you use may depend on your DBMS, which one you’re the most comfortable using, and perhaps also whether your organisation has any coding conventions that dictate which one should be used.

SQL Equals (=) Operator for Beginners

December 1, 2020December 1, 2020 by Ian

The equals operator (=) is probably the most commonly used operator in SQL. It compares the equality of two expressions. Even if you’ve only just begun your SQL journey, you’ll probably know this operator.

SQL NOT Operator for Beginners

December 1, 2020 by Ian

In SQL, the NOT operator negates a Boolean input (it reverses the value of any Boolean expression). Therefore it returns TRUE when the expression is FALSE.