Running a case-insensitive cypher query

Question

Is it possible to run a case-insensitive cypher query on neo4j?

When I type into this:

start n=node(*) 
match n-[]->m 
where (m.name="Neo") 
return m

it returns one row. But when I type into this:

start n=node(*) 
match n-[]->m 
where (m.name="neo") 
return m

it does not return anything; because the name is saved as "Neo". Is there a simple way to run case-insensitive queries?

score 60 · Accepted Answer · edited Dec 05 '19 at 19:36

60

Yes, by using case insensitive regular expressions:

WHERE m.name =~ '(?i)neo'

https://neo4j.com/docs/cypher-manual/current/clauses/where/#case-insensitive-regular-expressions

edited Dec 05 '19 at 19:36

vaer-k

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answered Nov 18 '12 at 10:54

Volker Pacher

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8

1

=~ operator does not use Indexes – Abhi Apr 12 '17 at 11:23
2

how can I pass parameter here? `'(?i)$param'` and `'(?!)'+$param` doesn't work – vladkras Nov 21 '17 at 10:22
I think you have to use the entire regex string as the parameter. – mcv Jul 30 '20 at 22:03

rotgers · Answer 2 · 2017-01-05T16:01:54.457

10

Another way would be:

WHERE LOWER(m.Name) = LOWER("Neo")

And if you are using the Neo4j Client (.NET):

Client.Cypher.Match("(m:Entity)")
    .Where("LOWER(m.Name) = LOWER({name})")
    .WithParam("name", inputName)
    .Return(m => m.As<Entity>())
    .Results
    .FirstOrDefault();

edited Jan 05 '17 at 16:01

answered Jan 05 '17 at 15:46

rotgers

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This solution is easier to apply for parameter – thangdc94 Mar 09 '18 at 07:44
@rotgers Wouldn't using the LOWER() function affect index lookups defined on the actual string? – Partha Aug 25 '18 at 01:33
@Partha, no idea, I haven't touched Neo4j for over a year. – rotgers Aug 28 '19 at 12:53
4

FYI - LOWER() has been replaced with toLower(). [Doc link for string operators](https://neo4j.com/docs/cypher-manual/current/functions/string/#functions-tolower) – Jalakoo May 02 '20 at 16:33

score 2 · Answer 3 · edited Nov 21 '18 at 12:54

2

If anybody is looking on how to do this with a parameter, I managed to do it like this.

query = "{}{}{}".format('Match (n) WHERE n.pageName =~ "'"(?i)", name, '" RETURN n')

and "name" is the variable or your parameter

edited Nov 21 '18 at 12:54

Suraj Rao

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answered Nov 21 '18 at 12:47

Mursy Alguineedy

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Can you explain how this works, or even how to read it? – mcv Jul 30 '20 at 22:04
`"{}{}{}"` looks like placeholders and `.format` is going to take in arguments in order or replacing placeholders. Readability is definitely one issue here but the larger issue seems to be this is just string concatenation not parametrisation. So in I could just do this `$"Match (n) WHERE n.pageName =~ {(?i)} name RETURN n` (C# string interpolation) – Piotr Kula Oct 09 '20 at 08:40

score 0 · Answer 4 · answered Nov 25 '20 at 06:46

0

You can pass a parameter to the case insensitive regular expression like:

WHERE m.name =~'(?i)({param})

answered Nov 25 '20 at 06:46

Nikhil Jacob

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1

Running a case-insensitive cypher query

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