Added SparQL

docs/SPARQL.md

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+# SparQL
+
+> [!NOTE]
+> Resources taken from [this website](https://sparql.dev/)
+
+## SQL Queries
+
+### SELECT
+
+```SQL
+SELECT ?var1, ?var2, ...
+```
+
+### WHERE
+
+```SQL
+WHERE {
+    pattern1 .
+    pattern2 .
+    ...
+}
+```
+
+### FILTER
+
+It's used to restrict [`WHERE`](#where) clauses
+
+```SQL
+WHERE {
+  ?person <http://example.com/hasCar> ?car .
+  FILTER (?car = <http://example.com/Car1>)
+}
+```
+
+### OPTIONAL
+
+It's used to fetch available content if exists
+
+```SQL
+SELECT ?person ?car
+WHERE {
+  ?person <http://example.com/hasCar> ?car .
+  OPTIONAL {
+    ?car <http://example.com/hasColor> ?color .
+  }
+}
+```
+
+### LIMIT
+
+Limits results
+
+```SQL
+LIMIT 10 -- Take only 10 results
+```
+
+## SparQL functions
+
+### COUNT
+
+```SQL
+SELECT (COUNT(?person) AS ?count)
+WHERE {
+  ?person <http://example.com/hasCar> ?car .
+}
+```
+