Difference between revisions of "SQL Relational operators"
From Lianjapedia
Yvonne.milne (Talk | contribs) m (1 revision: SQL) |
Helen.george (Talk | contribs) |
||
| (2 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
==Purpose== | ==Purpose== | ||
Relational Operators | Relational Operators | ||
| − | |||
==Syntax== | ==Syntax== | ||
<expression1> operator <expression2> | <expression1> operator <expression2> | ||
| − | |||
==See Also== | ==See Also== | ||
[[SQL INSERT|INSERT]], [[SQL OPERATORS]], [[SQL SELECT|SELECT]], [[SQL UPDATE|UPDATE]] | [[SQL INSERT|INSERT]], [[SQL OPERATORS]], [[SQL SELECT|SELECT]], [[SQL UPDATE|UPDATE]] | ||
| − | |||
==Description== | ==Description== | ||
Relational Operators compare two expressions and evaluate to either True or False. | Relational Operators compare two expressions and evaluate to either True or False. | ||
| − | + | {| class="wikitable" width="100%" | |
| − | + | ||
| − | {| class="wikitable" | + | |
!Operator||Description | !Operator||Description | ||
|- | |- | ||
| − | |=||True if <expression1> and <expression2> are equal, otherwise False | + | |valign="top"|=||True if <expression1> and <expression2> are equal, otherwise False |
|- | |- | ||
| − | |<||True if <expression1> is less than <expression2>, otherwise False | + | |valign="top"|<||True if <expression1> is less than <expression2>, otherwise False |
|- | |- | ||
| − | |<=||True if <expression1> is less than or equal to <expression2>, otherwise False | + | |valign="top"|<=||True if <expression1> is less than or equal to <expression2>, otherwise False |
|- | |- | ||
| − | |>||True if <expression1> is greater than the <expression2>, otherwise False | + | |valign="top"|>||True if <expression1> is greater than the <expression2>, otherwise False |
|- | |- | ||
| − | |>=||True if <expression1> is greater than or equal to <expression2>, otherwise False | + | |valign="top"|>=||True if <expression1> is greater than or equal to <expression2>, otherwise False |
|- | |- | ||
| − | |<>||True if <expression1> and <expression2> are not equal, otherwise False | + | |valign="top"|<>||True if <expression1> and <expression2> are not equal, otherwise False |
|- | |- | ||
| − | |!=||True if <expression1> and <expression2> are not equal, otherwise False | + | |valign="top"|!=||True if <expression1> and <expression2> are not equal, otherwise False |
|- | |- | ||
| − | |#||True if <expression1> and <expression2> are not equal, otherwise False | + | |valign="top"|#||True if <expression1> and <expression2> are not equal, otherwise False |
|- | |- | ||
| − | |$||True if <expression1> is a sub string of <expression2>. Both <expression1> and <expression2>must be character strings. | + | |valign="top"|$||True if <expression1> is a sub string of <expression2>. Both <expression1> and <expression2>must be character strings. |
|- | |- | ||
| − | |<nowiki>|</nowiki>||True if <expression2> is a sub string of <expression1>. Both <expression1> and <expression2>must be character strings. | + | |valign="top"|<nowiki>|</nowiki>||True if <expression2> is a sub string of <expression1>. Both <expression1> and <expression2>must be character strings. |
|- | |- | ||
| − | |==||True if <expression1> and <expression2> match, otherwise False. Both <expression1> and <expression2>must be character strings. The <expression2> can contain the wildcards below. | + | |valign="top"|==||True if <expression1> and <expression2> match, otherwise False. Both <expression1> and <expression2>must be character strings. The <expression2> can contain the wildcards below. |
|- | |- | ||
|} | |} | ||
| − | |||
Wildcards for == pattern matching: | Wildcards for == pattern matching: | ||
| − | + | {| class="wikitable" width="100%" | |
| − | + | ||
| − | {| class="wikitable" | + | |
!Operator||Description | !Operator||Description | ||
|- | |- | ||
| Line 56: | Line 48: | ||
|- | |- | ||
|} | |} | ||
| − | |||
==Example== | ==Example== | ||
| Line 92: | Line 83: | ||
| − | |||
| − | |||
[[Category:Documentation]] | [[Category:Documentation]] | ||
[[Category:SQL|Operators,Relational]] | [[Category:SQL|Operators,Relational]] | ||
Latest revision as of 11:37, 30 January 2013
Contents
Purpose
Relational Operators
Syntax
<expression1> operator <expression2>
See Also
INSERT, SQL OPERATORS, SELECT, UPDATE
Description
Relational Operators compare two expressions and evaluate to either True or False.
| Operator | Description |
|---|---|
| = | True if <expression1> and <expression2> are equal, otherwise False |
| < | True if <expression1> is less than <expression2>, otherwise False |
| <= | True if <expression1> is less than or equal to <expression2>, otherwise False |
| > | True if <expression1> is greater than the <expression2>, otherwise False |
| >= | True if <expression1> is greater than or equal to <expression2>, otherwise False |
| <> | True if <expression1> and <expression2> are not equal, otherwise False |
| != | True if <expression1> and <expression2> are not equal, otherwise False |
| # | True if <expression1> and <expression2> are not equal, otherwise False |
| $ | True if <expression1> is a sub string of <expression2>. Both <expression1> and <expression2>must be character strings. |
| | | True if <expression2> is a sub string of <expression1>. Both <expression1> and <expression2>must be character strings. |
| == | True if <expression1> and <expression2> match, otherwise False. Both <expression1> and <expression2>must be character strings. The <expression2> can contain the wildcards below. |
Wildcards for == pattern matching:
| Operator | Description |
|---|---|
| _ | Any single character |
| % | Zero or more characters |
Example
SELECT name, address, balance, cost*1.15; FROM accounts; WHERE paid_date = date(); ORDER BY name, paid_date SELECT name, address, balance, cost*1.15; FROM accounts; WHERE paid_date <= date(); ORDER BY name, paid_date SELECT name, address, balance, cost*1.15; FROM accounts; WHERE paid_date <> date(); ORDER BY name, paid_date SELECT name, address, balance, cost*1.15; FROM accounts; WHERE name == "%inc%"; ORDER BY name, paid_date SELECT name, address, balance, cost*1.15; FROM accounts; WHERE name | "inc"; ORDER BY name, paid_date SELECT name, address, balance, cost*1.15; FROM accounts; WHERE name $ "BigCo inc, BigCo plc"; ORDER BY name, paid_date
