How to do a Case Insensitive search on Azure DocumentDb?

问题

is it possible to perform a case insensitive search on DocumnetDb?

Let's say I have a record with 'name' key and value as "Timbaktu"

This will work:

select * from json j where j.name  = "Timbaktu"

This wont:

select * from json j where j.name  = "timbaktu"

So how do yo do a case insensitive search?

Thanks in advance.

Regards.

回答1:

There are two ways to do this. 1. use the built-in LOWER/UPPER function, for example,

select * from json j where LOWER(j.name) = 'timbaktu'

This will require a scan though. Another more efficient way is to store a "canonicalized" form e.g. lowercase and use that for querying. For example, the JSON would be

{ name: "Timbaktu", nameLowerCase: "timbaktu" }

Then use it for querying like:

select * from json j WHERE j.nameLowerCase = "timbaktu"

Hope this helps.

回答2:

Perhaps this is an ancient case, I just want to provide a workaround.

You could use UDF in azure cosmos db.

udf:

function userDefinedFunction(str){
    return str .toLowerCase();
}

And use below sql to query results:

SELECT c.firstName FROM c where udf.lowerConvert(c.firstName) = udf.lowerConvert('John')

来源：https://stackoverflow.com/questions/30512806/how-to-do-a-case-insensitive-search-on-azure-documentdb