{{Warning| There are relation differences between {{IMSMANG}} 5.08.04 and 6.0 database meaning that FKeys constrains and cascading rules have been changed even for tables that existed in 5.08.04.}}
{{TOC right}}
== Introduction ==__NOEDITSECTION__
{{Note | If an column name in PostgreSQL is written with upper case but not enclosed into double quotes, it will be created in lower case in the database.}}
=== CAST AS CHAR CHARSET utf8 and _utf8 (mySQLMySQL) ===__NOEDITSECTION__
In some (older) MySQL versions, UTF-8 was not the default character set and strings thus needed to be explicitly converted to UTF-8. This is not the case in PostgreSQL and UTF-8 related syntax as used in MySQL does not work in PostgreSQL. Below are two examples encountered in {{IMSMANG}} views.
</pre>
=== IF and IFNULL (mySQLMySQL) / CASE (PostgreSQL) statements (conditional expressions) ===__NOEDITSECTION__
The statements IF() and IFNULL() do not exist in PostgreSQL. In PostgreSQL, the CASE statement is used for conditional expressions. The syntax of the CASE statement is as follows: