Modern SharePoint CAML query with multiple criteria - sharepoint

Question

I am new to CAML. CAML seems like a great way to filter lists, but I am struggling to write nested and/or statements.
I am trying to start out small and write one CAML query with only two conditions so I can get the hang of it. Below is my failed attempt.
<View>
<Query>
<Where>
<and>
<Contains>
<FieldRef Name='PracticeArea_x0028_s_x0029_' />
<Value Type='Text'>Lean</Value>
</Contains>
<NotInclude>
<FieldRef Name='PracticeArea_x0028_s_x0029_' />
<Value Type='Text'>,</Value>
</NotInclude>
</and>
</Where>
</Query>
</View>
Any help, support, and/or insight this community can provide is greatly appreciated.

Answer 1

NotInclude used for Lookup field that allows multiple values, so won't work if you filter against a text field.
https://learn.microsoft.com/en-us/sharepoint/dev/schema/notincludes-element-query
You could filter by Contains first and then filter by Linq or similar approach.
SPList list = web.Lists.TryGetList("TestFilter");
SPQuery spQuery = new SPQuery();
spQuery.Query = #"<Where>
<Contains>
<FieldRef Name='PracticeArea' />
<Value Type='Text'>Lean</Value>
</Contains>
</Where>";
var items = list.GetItems(spQuery);
var filterItems=items.Cast<SPListItem>().Where(item => string.Format("{0}",item["PracticeArea"]).IndexOf(',') <0);
Console.WriteLine(filterItems.Count());