Fix #103 - Consistent use of Example subchapters

Author: kibeha

docs/4-language-usage/3-dml-and-sql/1-general/g-3120.md

@@ -21,6 +21,19 @@ select last_name
  where extract(month from hire_date) = extract(month from sysdate);
 ```
 
+If the `jobs` table has no `employee_id` column and `employees` has one this query will not raise an error but return all rows of the `employees` table as a subquery is allowed to access columns of all its parent tables - this construct is known as correlated subquery.
+
+``` sql
+select last_name
+      ,first_name
+  from employees
+ where employee_id in (
+          select employee_id
+            from jobs
+           where job_title like '%Manager%'
+       );
+```
+
 ## Example (better)
 
 ``` sql
@@ -47,23 +60,6 @@ select emp.last_name
  where extract(month from emp.hire_date) = extract(month from sysdate);
 ```
 
-## Example Subquery (bad)
-
-If the `jobs` table has no `employee_id` column and `employees` has one this query will not raise an error but return all rows of the `employees` table as a subquery is allowed to access columns of all its parent tables - this construct is known as correlated subquery.
-
-``` sql
-select last_name
-      ,first_name
-  from employees
- where employee_id in (
-          select employee_id
-            from jobs
-           where job_title like '%Manager%'
-       );
-```
-
-## Example Subquery (good)
-
 If the `jobs` table has no `employee_id` column this query will return an error due to the directive (given by adding the table alias to the column) to read the `employee_id` column from the `jobs` table.
 
 ``` sql
@@ -75,4 +71,4 @@ select emp.last_name
             from jobs j
            where j.job_title like '%Manager%'
        );
-```
+```

docs/4-language-usage/3-dml-and-sql/1-general/g-3195.md

@@ -18,14 +18,16 @@ select e.employee_id
 
 ## Example (good)
 
+Using a wildcard:
+
 ``` sql
 select e.employee_id
       ,e.last_name
   from employees e
  where e.last_name like 'Smith%';
 ```
 
-## Example (good)
+Change to equality operator instead:
 
 ``` sql
 select e.employee_id

docs/4-language-usage/3-dml-and-sql/3-transaction-control/g-3310.md

@@ -67,7 +67,7 @@ end;
 /
 ```
 
-## Example (better)
+## Example (best)
 
 (Assuming suitable foreign key relationship exists to allow updating a join.)
 

docs/4-language-usage/5-exception-handling/g-5040.md

@@ -33,7 +33,7 @@ end;
 /
 ```
 
-## Example (exception to the rule)
+An exception to the rule where `when others` can be good to log the error and then re-raise it:
 
 ``` sql
 begin

docs/4-language-usage/8-patterns/3-validating-input-parameter-size/g-8310.md

@@ -49,7 +49,7 @@ end department_api;
 /
 ```
 
-## Function call
+The exception should be handled where the function is called, like this:
 
 ``` sql
 ...