Bad data - it's everywhere and a common problem is badly formatted dates. "conversion failed when converting date and/or time from character string" is the message returned in such situations. It's not unique to SQL and will be seen in other languages such as Python, C#, Java and others. In this post, we look at the why and how you can fix it. Getting to the bottom of … [Read more...] about How to fix “conversion failed when converting date and/or time from character string”
sql server
Using SQL GROUPING SETS for Multiple GROUP BY Queries in a Single Query
SQL GROUPING SETS is a feature of the SQL language that allows you to specify multiple group by sets in a single query. The best way to demonstrate this is with code and examples. So imagine you have table of sales data which contained the following fields: product region sale_amount A visual of this would look like: Now say you had a requirement to … [Read more...] about Using SQL GROUPING SETS for Multiple GROUP BY Queries in a Single Query
How To Use SQL to Convert a STRING to an INT
Using SQL to convert a string to an int is used in a variety of situations. You may have text data that you cannot alter at the source and you need to get some accurate answers from it. You may also have text data that you want to insert to an integer column. There could be other reasons too. There is an easy solution to this and I will show you examples in both SQL Server … [Read more...] about How To Use SQL to Convert a STRING to an INT
How to Use SQL CASE for Conditional Logic in Your SQL Queries
SQL CASE provides the author of the query with the ability to perform conditional logic in their SQL queries for SELECT, INSERT, UPDATE, DELETE. It is also possible to use it with SET, IN, HAVING, ORDER BY and WHERE. It comes in two formats: simple case search case Simple SQL CASE The simple CASE expression compares an expression to a set of simple expressions to det … [Read more...] about How to Use SQL CASE for Conditional Logic in Your SQL Queries
Using ISNULL in SQL Server to Replace NULL Values
There are different ways to handle NULL's and I wrote about one such way in my last post. In this post, we look at SQL ISNULL() and specifically at the SQL Server version. MySQL does have this function but it behaves a little differently as it returns a boolean value. Let's look at the syntax ISNULL(check_expression, replacement_value) check_expression - this is the … [Read more...] about Using ISNULL in SQL Server to Replace NULL Values