Use wildcard characters in conditions for string values

You can use wildcard characters with the following operators when you build queries that include conditions on string values:

FetchXml

like
not-like
begins-with
not-begin-with
ends-with
not-end-with

More information: Query data using FetchXml

QueryExpression

ConditionOperator.Like
ConditionOperator.NotLike
ConditionOperator.BeginsWith
ConditionOperator.DoesNotBeginWith
ConditionOperator.EndsWith
ConditionOperator.DoesNotEndWith

More information: Filter rows using QueryExpression

Web API

contains
not contains
startswith
not startswith
endswith
not endswith

More information: Use OData query functions

When you use these condition operators, you can use certain characters to represent wildcards in your search criteria. The following table describes the characters you can use.

Characters	Description	T-SQL Documentation and examples
%	Matches any string of zero or more characters. This wildcard character can be used as either a prefix or a suffix.	Percent character (Wildcard - Character(s) to Match) (Transact-SQL)
_	Matches any single character in a string comparison operation that involves pattern matching.	_ (Wildcard - Match One Character) (Transact-SQL)
[]	Matches any single character in the range or set that's specified between square brackets.	[ ] (Wildcard - Character(s) to Match) (Transact-SQL)
[^]	Matches any single character that isn't in the range or set that's specified between the square brackets.	[^] (Wildcard - Character(s) Not to Match) (Transact-SQL)

Search for strings that contain wildcard characters

You can use the wildcard pattern matching characters as literal characters. To use a wildcard character as a literal character, enclose the wildcard character in brackets. More information: Using Wildcard Characters As Literals.

Don't use leading wild cards

Queries which use condition operators with implicit leading wild cards (like ends-with) or explicit leading wild cards will be less performant and can lead to poor performance across the organization in certain scenarios. More information:

• Optimize performance using FetchXml
• Optimize performance using QueryExpression

Queries that use these anti-patterns introduce performance problems because the queries can't be optimized.

FetchXml

Don't use trailing wild cards in expressions using like, begins-with, not-begin-with, ends-with, or not-end-with. Here are some examples of trailing wildcards:

Bad Examples
<condition attribute='name' operator='like' value='%value' />
<condition attribute='name' operator='begins-with' value='%value' />
<condition attribute='name' operator='not-begins-with' value='%value' />
<condition attribute='name' operator='ends-with' value='value' />
<condition attribute='name' operator='not-ends-with' value='value' />

QueryExpression

Don't use leading wild cards in expressions using Like, BeginsWith, DoesNotBeginWith, EndsWith, or DoesNotEndWith. Here are some examples of excess wildcards:

Bad Examples
query.Criteria.AddCondition("name", ConditionOperator.Like, "%value");
query.Criteria.AddCondition("name", ConditionOperator.BeginsWith, "%value");
query.Criteria.AddCondition("name", ConditionOperator.DoesNotBeginWith, "%value");
query.Criteria.AddCondition("name", ConditionOperator.EndsWith, "value");
query.Criteria.AddCondition("name", ConditionOperator.DoesNotEndWith, "value");

Web API

Don't use leading wild cards in expressions using like, startswith, not startswith, endswith, or not endswith. Here are some examples of excess wildcards:

Bad Examples
like(name,'%value')
startswith(name,'%value')
not startswith(name,'%value')
endswith(name,'value%')
not endswith(name,'value%')

See also

Filter rows using FetchXml
Filter rows using QueryExpression
Query data using the Web API