Added NLS_UPPER function as per DOCS-295

product_docs/docs/epas/17/reference/sql_reference/03_functions_and_operators/nls_upper.mdx

@@ -0,0 +1,31 @@
+---
+title: "NLS_UPPER function"
+---
+
+`NLS_UPPER` returns char with all letters in uppercase.
+
+```sql
+NLS_UPPER(char [, 'nlsparam'])
+```
+
+where char and 'nlsparam' can be any of the data types like CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB. The returned string is of VARCHAR2 data type if char is a character datatype and a LOB if char is a LOB data type. The return string is in the same character set as char.
+
+## Examples
+
+```sql
+SELECT nls_upper('abcDef', 'NLS_SORT = XGERMAN');
+__OUTPUT__
+ nls_upper 
+-----------
+ ABCDEF
+(1 row)
+```
+
+```sql
+SELECT nls_upper('Gloße', 'NLS_SORT = XDANISH');
+__OUTPUT__
+ nls_upper 
+-----------
+ GLOSSE
+(1 row)
+```