added files

Author: soyeric128

docs/en/sql-reference/20-sql-functions/06-string-functions/ltrim.md

@@ -7,6 +7,8 @@ import FunctionDescription from '@site/src/components/FunctionDescription';
 
 Removes specific characters from the beginning (left side) of a string.
 
+See also: [RTRIM](rtrim.md)
+
 ## Syntax
 
 ```sql

docs/en/sql-reference/20-sql-functions/06-string-functions/rtrim.md

@@ -7,6 +7,8 @@ import FunctionDescription from '@site/src/components/FunctionDescription';
 
 Removes specific characters from the end (right side) of a string.
 
+See also: [LTRIM](ltrim.md)
+
 ## Syntax
 
 ```sql

docs/en/sql-reference/20-sql-functions/06-string-functions/trim-both.md

@@ -0,0 +1,25 @@
+---
+title: TRIM_BOTH
+---
+
+Removes specific characters from both ends of a string.
+
+See also: [TRIM](trim.md)
+
+## Syntax
+
+```sql
+TRIM_BOTH(<string>, <trim_character>)
+```
+
+## Examples
+
+```sql
+SELECT TRIM_BOTH('xxdatabendxx', 'xx');
+
+┌─────────────────────────────────┐
+│ trim_both('xxdatabendxx', 'xx') │
+├─────────────────────────────────┤
+│ databend                        │
+└─────────────────────────────────┘
+```

docs/en/sql-reference/20-sql-functions/06-string-functions/trim-leading.md

@@ -0,0 +1,25 @@
+---
+title: TRIM_LEADING
+---
+
+Removes specific characters from the beginning (left side) of a string.
+
+See also: [TRIM_TRAILING](trim-trailing.md)
+
+## Syntax
+
+```sql
+TRIM_LEADING(<string>, <trim_character>)
+```
+
+## Examples
+
+```sql
+SELECT TRIM_LEADING('xxdatabend', 'xx');
+
+┌──────────────────────────────────┐
+│ trim_leading('xxdatabend', 'xx') │
+├──────────────────────────────────┤
+│ databend                         │
+└──────────────────────────────────┘
+```

docs/en/sql-reference/20-sql-functions/06-string-functions/trim-trailing.md

@@ -0,0 +1,25 @@
+---
+title: TRIM_TRAILING
+---
+
+Removes specific characters from the end (right side) of a string.
+
+See also: [TRIM_LEADING](trim-leading.md)
+
+## Syntax
+
+```sql
+TRIM_TRAILING(<string>, <trim_character>)
+```
+
+## Examples
+
+```sql
+SELECT TRIM_TRAILING('databendxx', 'xx');
+
+┌───────────────────────────────────┐
+│ trim_trailing('databendxx', 'xx') │
+├───────────────────────────────────┤
+│ databend                          │
+└───────────────────────────────────┘
+```

docs/en/sql-reference/20-sql-functions/06-string-functions/trim.md

@@ -7,6 +7,8 @@ import FunctionDescription from '@site/src/components/FunctionDescription';
 
 Removes specific characters or spaces from a string, optionally specifying the position (BOTH, LEADING, or TRAILING).
 
+See also: [TRIM_BOTH](trim-both.md)
+
 ## Syntax
 
 ```sql