gluesql · panarch · May 6, 2023 · May 2, 2023 · May 6, 2023 · May 6, 2023
diff --git a/docs/docs/sql-syntax/functions/text/ascii.md b/docs/docs/sql-syntax/functions/text/ascii.md
@@ -1 +1,90 @@
-# ASCII
+# ASCII
+
+The ASCII function in SQL returns the ASCII value for the first character of the specified string. 
+
+## Syntax
+
+The syntax for the ASCII function in SQL is:
+
+```sql
+ASCII ( single_character_text )
+```
+
+## Parameters
+
+- `single_character_text`: This is the string that the ASCII value should be returned for. It should be a single character string. 
+
+## Examples
+
+Let's consider a few examples to understand how to use the ASCII function.
+
+To get the ASCII value of a character:
+
+```sql
+VALUES(ASCII('A'));
+```
+
+This will return `65`, which is the ASCII value for 'A'.
+
+Please note that the ASCII function expects a single character value. If a string with more than one character is passed, it will throw an error. For instance:
+
+```sql
+VALUES(ASCII('AB'));
+```
+
+This will throw an error because 'AB' contains more than one character.
+
+You can also use the ASCII function in a SELECT statement. Consider the following table named 'Ascii':
+
+| id  | text |
+| --- | ---- |
+| 1   | 'F'  |
+
+```sql
+CREATE TABLE Ascii (
+    id INTEGER,
+    text TEXT
+);
+INSERT INTO Ascii VALUES (1, 'F');
+```
+
+You can select the ASCII value of the 'text' column:
+
+```sql
+SELECT ASCII(text) AS ascii FROM Ascii;
+```
+
+This will return `70`, which is the ASCII value for 'F'.
+
+The ASCII function can also take a string directly:
+
+```sql
+SELECT ASCII('a') AS ascii FROM Ascii;
+```
+
+This will return `97`, which is the ASCII value for 'a'.
+
+If a non-ASCII character is passed to the function, it will throw an error. For instance:
+
+```sql
+SELECT ASCII('ㄱ') AS ascii FROM Ascii;
+```
+
+This will throw an error because 'ㄱ' is not an ASCII character.
+
+If no argument is passed to the ASCII function, it will also throw an error:
+
+```sql
+SELECT ASCII() AS ascii FROM Ascii;
+```
+
+This will throw an error because the ASCII function expects one argument.
+
+Remember, the ASCII function expects a single character. If the column value contains more than one character, it will throw an error:
+
+```sql
+INSERT INTO Ascii VALUES (1, 'Foo');
+SELECT ASCII(text) AS ascii FROM Ascii;
+```
+
+This will throw an error because 'Foo' contains more than one character.
diff --git a/docs/docs/sql-syntax/functions/text/chr.md b/docs/docs/sql-syntax/functions/text/chr.md
@@ -1 +1,82 @@
-# CHR
+# CHR
+
+The CHR function in SQL returns the character represented by the specified ASCII value.
+
+## Syntax
+
+The syntax for the CHR function in SQL is:
+
+```sql
+CHR ( ascii_value )
+```
+
+## Parameters
+
+- `ascii_value`: This is the ASCII value for which the character should be returned. It should be an integer value between 0 and 255.
+
+## Examples
+
+Let's consider a few examples to understand how to use the CHR function.
+
+To get the character for an ASCII value:
+
+```sql
+VALUES(CHR(70));
+```
+
+This will return `'F'`, which is the character for the ASCII value 70.
+
+Please note that the CHR function expects an integer value between 0 and 255. If a value outside this range is passed, it will throw an error. For instance:
+
+```sql
+VALUES(CHR(7070));
+```
+
+This will throw an error because 7070 is not a valid ASCII value.
+
+You can also use the CHR function in a SELECT statement. Consider the following table named 'Chr':
+
+| id  | num |
+| --- | --- |
+| 1   | 70  |
+
+```sql
+CREATE TABLE Chr (
+    id INTEGER,
+    num INTEGER
+);
+INSERT INTO Chr VALUES (1, 70);
+```
+
+You can select the character for the 'num' column:
+
+```sql
+SELECT CHR(num) AS chr FROM Chr;
+```
+
+This will return `'F'`, which is the character for the ASCII value 70.
+
+The CHR function can also take an integer value directly:
+
+```sql
+SELECT CHR(65) AS chr FROM Chr;
+```
+
+This will return `'A'`, which is the character for the ASCII value 65.
+
+If a non-integer value is passed to the function, it will throw an error. For instance:
+
+```sql
+SELECT CHR('ukjhg') AS chr FROM Chr;
+```
+
+This will throw an error because 'ukjhg' is not an integer value.
+
+Remember, the CHR function expects an integer value between 0 and 255. If the column value is outside this range, it will throw an error:
+
+```sql
+INSERT INTO Chr VALUES (1, 4345);
+SELECT CHR(num) AS chr FROM Chr;
+```
+
+This will throw an error because 4345 is not a valid ASCII value.
diff --git a/docs/docs/sql-syntax/functions/text/concat-ws.md b/docs/docs/sql-syntax/functions/text/concat-ws.md
@@ -1 +1,60 @@
-# CONCAT_WS
+# CONCAT_WS
+
+The CONCAT_WS function in SQL concatenates two or more strings into one string with a separator. 
+
+## Syntax
+
+The syntax for the CONCAT_WS function in SQL is:
+
+```sql
+CONCAT_WS ( separator, string1, string2, ..., stringN )
+```
+
+## Parameters
+
+- `separator`: This is the string that will be placed between each string to be concatenated.
+- `string1`, `string2`, ..., `stringN`: These are the strings that you wish to concatenate together. 
+
+## Examples
+
+Let's consider a few examples to understand how to use the CONCAT_WS function.
+
+To concatenate strings with a comma separator:
+
+```sql
+VALUES(CONCAT_WS(',', 'AB', 'CD', 'EF'));
+```
+
+This will return `'AB,CD,EF'`.
+
+You can also concatenate more than two strings:
+
+```sql
+SELECT CONCAT_WS('/', 'ab', 'cd', 'ef') AS myconcat;
+```
+
+This will return `'ab/cd/ef'`.
+
+The CONCAT_WS function will skip any NULL values:
+
+```sql
+SELECT CONCAT_WS('', 'ab', 'cd', NULL, 'ef') AS myconcat;
+```
+
+This will return `'abcdef'`.
+
+The CONCAT_WS function can also take non-string arguments:
+
+```sql
+SELECT CONCAT_WS('', 123, 456, 3.14) AS myconcat;
+```
+
+This will return `'1234563.14'`. In this case, the integers and float values are implicitly converted to strings before concatenation.
+
+However, the CONCAT_WS function expects at least two arguments. If fewer than two arguments are passed to the CONCAT_WS function, it will throw an error:
+
+```sql
+SELECT CONCAT_WS() AS myconcat;
+```
+
+This will throw an error because the CONCAT_WS function expects at least two arguments.
diff --git a/docs/docs/sql-syntax/functions/text/concat.md b/docs/docs/sql-syntax/functions/text/concat.md
@@ -1 +1,59 @@
-# CONCAT
+# CONCAT
+
+The CONCAT function in SQL concatenates two or more strings into one string.
+
+## Syntax
+
+The syntax for the CONCAT function in SQL is:
+
+```sql
+CONCAT ( string1, string2, ..., stringN )
+```
+
+## Parameters
+
+- `string1`, `string2`, ..., `stringN`: These are the strings that you wish to concatenate together. 
+
+## Examples
+
+Let's consider a few examples to understand how to use the CONCAT function.
+
+To concatenate two strings:
+
+```sql
+SELECT CONCAT('ab', 'cd') AS myconcat;
+```
+
+This will return `'abcd'`.
+
+You can also concatenate more than two strings:
+
+```sql
+SELECT CONCAT('ab', 'cd', 'ef') AS myconcat;
+```
+
+This will return `'abcdef'`.
+
+If any string in the CONCAT function is NULL, the function will return NULL:
+
+```sql
+SELECT CONCAT('ab', 'cd', NULL, 'ef') AS myconcat;
+```
+
+This will return NULL.
+
+The CONCAT function can also take non-string arguments:
+
+```sql
+SELECT CONCAT(123, 456, 3.14) AS myconcat;
+```
+
+This will return `'1234563.14'`. In this case, the integers and float values are implicitly converted to strings before concatenation.
+
+However, the CONCAT function expects at least one argument. If no arguments are passed to the CONCAT function, it will throw an error:
+
+```sql
+SELECT CONCAT() AS myconcat;
+```
+
+This will throw an error because the CONCAT function expects at least one argument.
diff --git a/docs/docs/sql-syntax/functions/text/find-idx.md b/docs/docs/sql-syntax/functions/text/find-idx.md
@@ -1 +1,83 @@
-# FIND_IDX
+# FIND_IDX
+
+The `FIND_IDX` function in SQL is used to return the position of the first occurrence of a substring in a string, optionally after a specified position.
+
+## Syntax
+
+The syntax for the `FIND_IDX` function in SQL is:
+
+```sql
+FIND_IDX ( string, substring, [ start_position ] )
+```
+
+## Parameters
+
+- `string`: The string where the search will take place.
+- `substring`: The substring to find.
+- `start_position` (optional): The position at which to start the search. The first position in the string is 0. If the `start_position` is not specified, the search starts from the beginning of the string.
+
+## Examples
+
+Let's consider a few examples to understand how to use the `FIND_IDX` function.
+
+Find the position of 'rg' in 'pork':
+
+```sql
+SELECT FIND_IDX('pork', 'rg') AS test;
+```
+
+This will return 0, as 'rg' is not found in 'pork'.
+
+Find the position of 'rg' in 'burger':
+
+```sql
+SELECT FIND_IDX('burger', 'rg') AS test;
+```
+
+This will return 3, as the first occurrence of 'rg' in 'burger' is at position 3.
+
+Find the position of 'r' in 'pork', starting from position 4:
+
+```sql
+SELECT FIND_IDX('pork', 'r', 4) AS test;
+```
+
+This will return 0, as 'r' is not found in 'pork' after position 4.
+
+Find the position of 'r' in 'burger', starting from position 4:
+
+```sql
+SELECT FIND_IDX('burger', 'r', 4) AS test;
+```
+
+This will return 6, as the first occurrence of 'r' in 'burger' after position 4 is at position 6.
+
+Find the position of an empty string in 'cheese':
+
+```sql
+SELECT FIND_IDX('cheese', '') AS test;
+```
+
+This will return 0, because the search starts at the first position by default and the empty string is considered to be found at the start of any string.
+
+Find the position of 's' in 'cheese':
+
+```sql
+SELECT FIND_IDX('cheese', 's') AS test;
+```
+
+This will return 5, as the first occurrence of 's' in 'cheese' is at position 5.
+
+Find the position of 'e' in 'cheese burger', starting from position 5:
+
+```sql
+SELECT FIND_IDX('cheese burger', 'e', 5) AS test;
+```
+
+This will return 6, because the search starts from position 5 and the next 'e' is at position 6.
+
+Using a NULL value as the substring will return NULL:
+
+```sql
+SELECT FIND_IDX('cheese', NULL) AS test;
+```