Add more examples to the where command doc

docs/user/ppl/cmd/where.rst

@@ -20,8 +20,10 @@ where <boolean-expression>
 
 * bool-expression: optional. any expression which could be evaluated to boolean value.
 
-Example 1: Filter result set with condition
-===========================================
+Examples
+========
+
+**Example 1: Filter result set with condition**
 
 The example show fetch all the document from accounts index with .
 
@@ -36,3 +38,142 @@ PPL query::
     | 13             | F      |
     +----------------+--------+
 
+**Example 2: Basic Field Comparison**
+
+The example shows how to filter accounts with balance greater than 40000.
+
+PPL query::
+
+    os> source=accounts | where balance > 40000 | fields account_number, balance;
+    fetched rows / total rows = 2/4
+    +----------------+---------+
+    | account_number | balance |
+    |----------------+---------|
+    | 1              | 45000   |
+    | 6              | 42000   |
+    +----------------+---------+
+
+**Example 3: Pattern Matching with LIKE**
+
+Pattern Matching with Underscore (_)
+
+The example demonstrates using LIKE with underscore (_) to match a single character.
+
+PPL query::
+
+    os> source=accounts | where LIKE(state, 'N_') | fields account_number, state;
+    fetched rows / total rows = 2/6
+    +----------------+-------+
+    | account_number | state |
+    |----------------+-------|
+    | 4              | NY    |
+    | 7              | NJ    |
+    +----------------+-------+
+
+Pattern Matching with Percent (%)
+
+The example demonstrates using LIKE with percent (%) to match multiple characters.
+
+PPL query::
+
+    os> source=accounts | where LIKE(state, 'CA%') | fields account_number, state;
+    fetched rows / total rows = 2/6
+    +----------------+-------+
+    | account_number | state |
+    |----------------+-------|
+    | 2              | CA    |
+    | 8              | CAL   |
+    +----------------+-------+
+
+**Example 4: Multiple Conditions**
+
+The example shows how to combine multiple conditions using AND operator.
+
+PPL query::
+
+    os> source=accounts | where age > 30 AND gender = 'F' | fields account_number, age, gender;
+    fetched rows / total rows = 2/5
+    +----------------+-----+--------+
+    | account_number | age | gender |
+    |----------------+-----+--------|
+    | 13             | 32  | F      |
+    | 24             | 36  | F      |
+    +----------------+-----+--------+
+
+**Example 5: Using IN Operator**
+
+The example demonstrates using IN operator to match multiple values.
+
+PPL query::
+
+    os> source=accounts | where state IN ('CA', 'NY') | fields account_number, state;
+    fetched rows / total rows = 3/6
+    +----------------+-------+
+    | account_number | state |
+    |----------------+-------|
+    | 2              | CA    |
+    | 4              | NY    |
+    | 8              | CA    |
+    +----------------+-------+
+
+**Example 6: NULL Checks**
+
+The example shows how to filter records with NULL values.
+
+PPL query::
+
+   os> source=accounts | where ISNULL(employer) | fields account_number, employer;
+   fetched rows / total rows = 2/8
+   +----------------+----------+
+   | account_number | employer |
+   |----------------+----------|
+   | 7              | null     |
+   | 15             | null     |
+   +----------------+----------+
+
+**Example 7: Complex Conditions**
+
+The example demonstrates combining multiple conditions with parentheses and logical operators.
+
+PPL query::
+
+    os> source=accounts | where (balance > 40000 OR age > 35) AND gender = 'M' | fields account_number, balance, age, gender;
+    fetched rows / total rows = 2/7
+    +----------------+---------+-----+--------+
+    | account_number | balance | age | gender |
+    |----------------+---------+-----+--------|
+    | 1              | 45000   | 38  | M      |
+    | 16             | 38000   | 39  | M      |
+    +----------------+---------+-----+--------+
+
+
+**Example 8: NOT Conditions**
+
+The example shows how to use NOT operator to exclude matching records.
+
+PPL query::
+
+    os> source=accounts | where NOT state = 'CA' | fields account_number, state;
+    fetched rows / total rows = 4/6
+    +----------------+-------+
+    | account_number | state |
+    |----------------+-------|
+    | 3              | TX    |
+    | 4              | NY    |
+    | 11             | FL    |
+    | 19             | WA    |
+    +----------------+-------+
+
+**Example 9: Field-to-Field Comparison**
+
+The example demonstrates comparing two fields from the same record.
+
+PPL query::
+
+    os> source=accounts | where employer_id = manager_id | fields account_number, employer_id, manager_id;
+    fetched rows / total rows = 1/5
+    +----------------+-------------+------------+
+    | account_number | employer_id | manager_id |
+    |----------------+-------------+------------|
+    | 4              | 101         | 101        |
+    +----------------+-------------+------------+