TRY CONVERT function in SQL Server 2012 скачать в хорошем качестве

TRY CONVERT function in SQL Server 2012

try convert function in sql sql server try_convert try_convert in sql server 2012 try convert sql try_parse vs try_convert sql server In this video we will discuss TRY_CONVERT function Difference between CONVERT and TRY_CONVERT functions Difference between TRY_PARSE and TRY_CONVERT functions Healthy diet is very important both for the body and mind. If you like Aarvi Kitchen recipes, please support by sharing, subscribing and liking our YouTube channel. Hope you can help.    / @aarvikitchen5572   TRY_CONVERT function Introduced in SQL Server 2012 Converts a value to the specified data type Returns NULL if the provided value cannot be converted to the specified data type If you request a conversion that is explicitly not permitted, then TRY_CONVERT fails with an error Syntax : TRY_CONVERT ( data_type, value, [style] ) Style parameter is optional. The range of acceptable values is determined by the target data_type. For the list of all possible values for style parameter, please visit the following MSDN article https://msdn.microsoft.com/en-us/libr... Example : Convert string to INT. As the string can be converted to INT, the result will be 99 as expected. SELECT TRY_CONVERT(INT, '99') AS Result Example : Convert string to INT. The string cannot be converted to INT, so TRY_CONVERT returns NULL SELECT TRY_CONVERT(INT, 'ABC') AS Result Example : Converting an integer to XML is not explicitly permitted. so in this case TRY_CONVERT fails with an error SELECT TRY_CONVERT(XML, 10) AS Result If you want to provide a meaningful error message instead of NULL when the conversion fails, you can do so using CASE statement or IIF function. Example : Using CASE statement to provide a meaningful error message when the conversion fails. SELECT CASE WHEN TRY_CONVERT(INT, 'ABC') IS NULL THEN 'Conversion Failed' ELSE 'Conversion Successful' END AS Result Output : As the conversion fails, you will now get a message 'Conversion Failed' instead of NULL Example : Using IIF function to provide a meaningful error message when the conversion fails. SELECT IIF(TRY_CONVERT(INT, 'ABC') IS NULL, 'Conversion Failed', 'Conversion Successful') AS Result What is the difference between CONVERT and TRY_CONVERT CONVERT will result in an error if the conversion fails, where as TRY_CONVERT will return NULL instead of an error. Since ABC cannot be converted to INT, CONVERT will return an error SELECT CONVERT(INT, 'ABC') AS Result Since ABC cannot be converted to INT, TRY_CONVERT will return NULL instead of an error SELECT TRY_CONVERT(INT, 'ABC') AS Result Example : Using TRY_CONVERT() function with table data. We will use the following Employees table for this example. SQL Script to create Employees table Create table Employees ( Id int primary key identity, Name nvarchar(10), Age nvarchar(10) ) Go Insert into Employees values ('Mark', '40') Insert into Employees values ('John', '20') Insert into Employees values ('Amy', 'THIRTY') Insert into Employees values ('Ben', '21') Insert into Employees values ('Sara', 'FIFTY') Insert into Employees values ('David', '25') Go The data type of Age column is nvarchar. So string values like (THIRTY, FIFTY ) are also stored. Now, we want to write a query to convert the values in Age column to int and return along with the Employee name. Notice TRY_CONVERT function returns NULL for the rows where age cannot be converted to INT. SELECT Name, TRY_CONVERT(INT, Age) AS Age FROM Employees If you use CONVERT instead of TRY_CONVERT, the query fails with an error. SELECT NAME, CONVERT(INT, Age) AS Age FROM Employees The above query returns the following error Conversion failed when converting the nvarchar value 'THIRTY' to data type int. Difference between TRY_PARSE and TRY_CONVERT functions TRY_PARSE can only be used for converting from string to date/time or number data types where as TRY_CONVERT can be used for any general type conversions. For example, you can use TRY_CONVERT to convert a string to XML data type, where as you can do the same using TRY_PARSE Converting a string to XML data type using TRY_CONVERT SELECT TRY_CONVERT(XML, '[root][child/][/root]') AS [XML] Text version of the video http://csharp-video-tutorials.blogspo... Slides http://csharp-video-tutorials.blogspo... All SQL Server Text Articles http://csharp-video-tutorials.blogspo... All SQL Server Slides http://csharp-video-tutorials.blogspo... All Dot Net and SQL Server Tutorials in English https://www.youtube.com/user/kudvenka... All Dot Net and SQL Server Tutorials in Arabic    / kudvenkatarabic