Tag: t-sql

How to Convert a Comma-Separated List into Rows in SQL Server

Posted on by Ian

So you have a comma-separated list, and now you need to insert it into the database. But the thing is, you need to insert each value in the list into its own table row. So basically, you need to split the list into its separate values, then insert each one of those values into a new row.

T-SQL now has a STRING_SPLIT() function that makes this type of operation a breeze. This function was first available in SQL Server 2016, and is available on databases with a compatibility level of 130 or above (how to check your database compatibility level and how to change it).

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How to Check a Database’s Compatibility Level in SQL Server using T-SQL

Posted on by Ian

In SQL Server, you can use T-SQL to check the compatibility level of a database. All you need to do is query sys.databases to find the compatibility level for the database in question.

Here’s an example:

SELECT compatibility_level
FROM sys.databases
WHERE name = 'WideWorldImporters';

Result:

compatibility_level
-------------------
130

This example returns the compatibility level of the WideWorldImporters database.

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What’s the MySQL Equivalent of STUFF() in SQL Server?

Posted on by Ian

If you’re familiar with SQL Server,  you might know that you can use the T-SQL STUFF() function to insert a string within a string.  As it turns out, MySQL has a similar function – but with a different name.

MySQL’s INSERT() function does essentially the same thing that the T-SQL STUFF() function does.

With the exception of a couple of minor differences (see below), both functions work exactly the same.

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How to Insert a String into another String in SQL Server using STUFF()

Posted on by Ian

In SQL Server, you can use the T-SQL STUFF() function to insert a string into another string. This enables you to do things like insert a word at a specific position. It also allows you to replace a word at a specific position.

Here’s the official syntax:

STUFF ( character_expression , start , length , replaceWith_expression )
  • character_expression is the original string. This can actually be a constant, variable, or column of either character or binary data.
  • start specifies the start position (i.e. where the new string will be inserted).
  • length is how many characters are to be deleted from the original string.
  • replaceWith_expression is the string that’s being inserted. replaceWith_expression can be a constant, variable, or column of either character or binary data.

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What is T-SQL?

Posted on by Ian

Transact-SQL, often abbreviated to T-SQL or even TSQL, is Microsoft’s and Sybase’s proprietary extension to SQL. Transact-SQL expands on the SQL standard to include extra features that aren’t included in the SQL standard.

Here’s an example of a simple T-SQL statement:

CREATE DATABASE Movies;

This is as simple as a T-SQL example could get. This creates a new database called Movies.

However, T-SQL provides for other options to be included in this statement, such as where the database files should be located, the size of those files, what their maximum size should be, and more.

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CHARINDEX() vs PATINDEX() in SQL Server – What’s the Difference?

Posted on by Ian

In SQL Server, you can use either the CHARINDEX() function or the PATINDEX() function to find a string within a string. These are Transact-SQL string functions, and they’re also available on Azure databases.

On the surface, these functions appear to do exactly the same thing, and in many cases, you could use whichever you prefer to use.

However, there a a couple of distinctions that could dictate which function you decide to use in certain scenarios. These can be summarized by the following:

  • PATINDEX() allows you to use wildcard characters to search for patterns. CHARINDEX() doesn’t.
  • CHARINDEX() accepts a third argument which allows you to specify the start position of the search. PATINDEX() doesn’t.

More detail on these points below.

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How to Find a List Item at a Specified Position in SQL Server

Posted on by Ian

Starting from SQL Server 2012, you can use the T-SQL CHOOSE() function to find a list item at a specified index position within a list.

The syntax goes like this:

CHOOSE ( index, val_1, val_2 [, val_n ] )

Where index is an integer that represents the position within the list that you want to return.

Example

Here’s an example:

SELECT CHOOSE(3, 'Marge', 'Homer', 'Bart') AS 'Who is at 3?';

Result:

Who is at 3?
------------
Bart

In this case, we want to find the item at position 3. The item at position 3 is Bart.
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How to Format Numbers in SQL Server

Posted on by Ian

Starting from SQL Server 2012, you can format numeric types using the T-SQL FORMAT() function. This function accepts three arguments; the number, the format, and an optional “culture” argument.

It returns a formatted string of type nvarchar.

The format is supplied as a format string. A format string defines how the output should be formatted.

Here’s an example:

SELECT FORMAT(1, 'N');

Result:

1.00

In this case, I used N as the second argument. This is the standard numeric format specifier for Number. This particular format specifier (N) results in the output being formatted with integral and decimal digits, group separators, and a decimal separator with optional negative sign. This argument is case-insensitive, so either N or n is fine.

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How to Format the Date & Time in SQL Server

Posted on by Ian

In SQL Server, you can use the T-SQL FORMAT() function to format the date and/or time. Simply provide two arguments; the date/time and the format to use.

The format is supplied as a format string. A format string defines how the output should be formatted.

The FORMAT() function also accepts an optional “culture” argument, which allows you to specify a language/locale that the results should adhere to.

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