Fix #38 - Created rule G-3195: Always use wildcards in a LIKE clause.

Author: kibeha

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

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+# G-3195: Always use wildcards in a LIKE clause.
+
+!!! tip "Minor"
+    Maintainability
+
+## Reason
+
+Using `like` without at least one wildcard (`%` or `_`) is unclear to a maintainer whether a wildcard is forgotten or it is meant as equality test. A common antipattern is also to forget that an underscore is a wildcard, so using `like` instead of equal can return unwanted rows. If the `char` datatype is involved, there is also the danger of `like` not using blank padded comparison where equal will. Depending on use case, you should either remember at least one wildcard or use normal equality operator.
+
+## Example (bad)
+
+``` sql
+select e.employee_id
+      ,e.last_name
+  from employees e
+ where e.last_name like 'Smith';
+```
+
+## Example (good)
+
+``` sql
+select e.employee_id
+      ,e.last_name
+  from employees e
+ where e.last_name like 'Smith%';
+```
+
+## Example (good)
+
+``` sql
+select e.employee_id
+      ,e.last_name
+  from employees e
+ where e.last_name = 'Smith';
+```