Should I use != or <> for not equal in T

 

I have seen SQL that uses both != and <> for not equal . What is the preferred syntax and why?

I like != , because <> reminds me of Visual Basic .

Technically they function the same if you're using SQL Server AKA T-SQL. If you're using it in stored procedures there is no performance reason to use one over the other. It then comes down to personal preference. I prefer to use <> as it is ANSI compliant.

You can find links to the various ANSI standards at...

http://en.wikipedia.org/wiki/SQL

Most databases support != (popular programming languages) and <> (ANSI).

Databases that support both != and <> :

  • MySQL 5.1: != and <>
  • PostgreSQL 8.3: != and <>
  • SQLite: != and <>
  • Oracle 10g: != and <>
  • Microsoft SQL Server 2000/2005/2008/2012/2016: != and <>
  • IBM Informix Dynamic Server 10: != and <>
  • InterBase/Firebird: != and <>
  • Apache Derby 10.6: != and <>
  • Sybase Adaptive Server Enterprise 11.0: != and <>

    • Databases that support the ANSI standard operator, exclusively :

  • IBM DB2 UDB 9.5: <>
  • Microsoft Access 2010: <>

    • '<>' is from the SQL-92 standard and '!=' is a proprietary T-SQL operator. It's available in other databases as well, but since it isn't standard you have to take it on a case-by-case basis.

    In most cases, you'll know what database you're connecting to so this isn't really an issue. At worst you might have to do a search and replace in your SQL.

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