{"id":799,"date":"2014-12-08T17:39:40","date_gmt":"2014-12-09T00:39:40","guid":{"rendered":"https:\/\/blogs.ubc.ca\/coetoolbox\/?page_id=799"},"modified":"2016-10-24T11:02:26","modified_gmt":"2016-10-24T18:02:26","slug":"comparison-keywords","status":"publish","type":"page","link":"https:\/\/blogs.ubc.ca\/coetoolbox\/databases\/comparison-keywords\/","title":{"rendered":"Comparison Keywords"},"content":{"rendered":"

IS NULL<\/h2>\n

A column value is NULL if it does not exist. The IS NULL operator is used to display all the rows for columns that do not have a value.<\/p>\n

SELECT *
\nFROM Students
\nWHERE StudentName IS NULL<\/span><\/p>\n

Note: it is not possible to test for NULL values with comparison operators such as =. The result of any arithmetic expression involving null is null.<\/p>\n

BETWEEN<\/h2>\n

The BETWEEN\u00a0operator is used to compare data for a range of values.<\/p>\n

SELECT *
\nFROM Students
\nWHERE Year BETWEEN<\/span> 2000 AND<\/span> 2015<\/p>\n

IN<\/h2>\n

The IN operator is used when you want to match a column with one of several possible values.<\/p>\n

SELECT *
\nFROM Students
\nWHERE Program IN<\/span> (‘MM’, ‘MMOR’)<\/p>\n

LIKE<\/h2>\n

The LIKE keyword is used to search entries with a given pattern. For example, the following query returns all the courses with id starting with BAMS.<\/p>\n

SELECT *
\nFROM Courses
\nWHERE CourseID LIKE<\/span> ‘BAMS%<\/span>‘\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 (‘BAMS*<\/span>‘ for MS Access)<\/span><\/em><\/p>\n

The syntax for a condition with LIKE operator is:<\/p>\n

expression<\/em> LIKE pattern<\/em><\/p>\n

where expression<\/em> is a character expression such as a column or field, and pattern<\/em> is a character expression that contains pattern searched. The patterns are expressed using wildcard characters:<\/p>\n