Sql Server Try_convert Function
SQL Server: TRY_CONVERT Function
In this post explains how to use the TRY_CONVERT function in SQL Server (Transact-SQL) with syntax and examples.
Description
In SQL Server (Transact-SQL), the TRY_CONVERT function tries to convert an expression from one datatype to another datatype. If the conversion fails, the function will return NULL. Otherwise, it will return the converted value.
Syntax
The syntax for the TRY_CONVERT function in SQL Server (Transact-SQL) is:
TRY_CONVERT( type [ (length) ], expression [ , style ] )Parameters or Arguments
- type
- length
- expression
- style
The datatype that you wish to convert expression to. It can be one of the following: bigint, int, smallint, tinyint, bit, decimal, numeric, money, smallmoney, float, real, datetime, smalldatetime, char, varchar, text, nchar, nvarchar, ntext, binary, varbinary, or image.
Optional. The length of the resulting data type for char, varchar, nchar, nvarchar, binary and varbinary.
The value to convert to another datatype.
Optional. The format used to convert between datatypes, such as a date format or string format. It can be one of the following values:
Converting datetime to character
| Value (without century) | Value (with century) | Explanation |
|---|---|---|
| 0 | 100 | mon dd yyyy hh:miAM/PM (Default) |
| 1 | 101 | mm/dd/yyyy (US standard) |
| 2 | 102 | yy.mm.dd (ANSI standard) |
| 3 | 103 | dd/mm/yy (British/French standard) |
| 4 | 104 | dd.mm.yy (German standard) |
| 5 | 105 | dd-mm-yy (Italian standard) |
| 6 | 106 | dd mon yy |
| 7 | 107 | Mon dd, yy |
| 8 | 108 | hh:mi:ss |
| 9 | 109 | mon dd yyyy hh:mi:ss:mmmAM/PM |
| 10 | 110 | mm-dd-yy (USA standard) |
| 11 | 111 | yy/mm/dd (Japan standard) |
| 12 | 112 | yymmdd (ISO standard) |
| 13 | 113 | dd mon yyyy hh:mi:ss:mmm (Europe standard - 24 hour clock) |
| 14 | 114 | hh:mi:ss:mmm (24 hour clock) |
| 20 | 120 | yyyy-mm-dd hh:mi:ss (ODBC canonical - 24 hour clock) |
| 21 | 121 | yyyy-mm-dd hh:mi:ss:mmm (ODBC canonical - 24 hour clock) |
| 126 | yyyy-mm-ddThh:mi:ss:mmm (ISO8601 standard) | |
| 127 | yyyy-mm-ddThh:mi:ss:mmmZ (ISO8601 standard) | |
| 130 | dd mon yyyy hh:mi:ss:mmmAM/PM (Hijri standard) | |
| 131 | dd/mm/yy hh:mi:ss:mmmAM/PM (Hijri standard) |
Converting float to real
| Value | Explanation |
|---|---|
| 0 | Maximum 6 digits (Default) |
| 1 | 8 digits |
| 2 | 16 digits |
Converting money to character
| Value | Explanation |
|---|---|
| 0 | No comma delimiters, 2 digits to the right of decimal (ie: 1234.56) |
| 1 | Comma delimiters, 2 digits to the right of decimal (ie: 1,234.56) |
| 2 | No comma delimiters, 4 digits to the right of decimal (ie: 1234.5678) |
Note
Applies To
The TRY_CONVERT function can be used in the following versions of SQL Server (Transact-SQL):
- SQL Server 2017, SQL Server 2016, SQL Server 2014, SQL Server 2012
Example
Let's look at some SQL Server TRY_CONVERT function examples and explore how to use the TRY_CONVERT function in SQL Server (Transact-SQL).
For example:
SELECT TRY_CONVERT(int, 14.85);
Output: 14
(result is a truncated int value)
SELECT TRY_CONVERT(float, 14.85);
Output: 14.85
(result is returned as a float value and is not truncated)
SELECT TRY_CONVERT(float, '14 Main St.');
Output: NULL
(result is NULL because conversion failed since this string value can not be converted to a float)
SELECT TRY_CONVERT(varchar, 15.6);
Output: '15.6'
(result is returned as a varchar)
SELECT TRY_CONVERT(varchar(2), 15.6);
Output: NULL
(result is NULL because conversion failed since the value will not fit in a 2 character varchar)
SELECT TRY_CONVERT(datetime, '2018-09-13');
Output: '2018-09-13 00:00:00.000'
(result is returned as a datetime)
SELECT TRY_CONVERT(varchar, '2018-09-13', 101);
Output: '09/13/2018'
(result is returned as a varchar with a style of 101 - mm/dd/yyyy (US standard) )