Data cleaning: Difference between revisions

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* MySQL {{kbd | key = SELECT * FROM table WHERE column IS NULL;}}<ref>[http://dev.mysql.com/doc/refman/5.0/en/working-with-null.html MySQL :: MySQL 5.0 Reference Manual :: 3.3.4.6 Working with NULL Values]</ref>
* MySQL {{kbd | key = SELECT * FROM table WHERE column IS NULL;}}<ref>[http://dev.mysql.com/doc/refman/5.0/en/working-with-null.html MySQL :: MySQL 5.0 Reference Manual :: 3.3.4.6 Working with NULL Values]</ref>


Finds whether a variable is NOT NULL
* MySQL {{kbd | key = SELECT * FROM table WHERE column IS NOT NULL;}}


== references ==
== references ==

Revision as of 18:29, 8 January 2014

is null

Finds whether a variable is NULL

  • PHP is_null
  • Google spreadsheet:
    • ISERR(value) " value - The value to be verified as an error type other than #N/A." ex: #NULL!
    • If the value is exactly NULL not #NULL!, You may use EXACT(value, "NULL")
  • MySQL SELECT * FROM table WHERE column IS NULL;[1]

Finds whether a variable is NOT NULL

  • MySQL SELECT * FROM table WHERE column IS NOT NULL;

references