Translate table values to text following a fixed pattern - sql

Question

We use software to store combinations of financial elements. Those elements are allowed in certain combinations. Exceptions of these combinations are SQL-like statements in the front-end, and are saved as numerical values in a database table like the following example:
+------+------+------+------+------+
| Col1 | Col2 | Col3 | Col4 | Col5 |
+------+------+------+------+------+
| 1 | 2 | 4 | 5 | 1 |
+------+------+------+------+------+
| -1 | 2 | 6 | 4 | 5 |
+------+------+------+------+------+
| 1 | 2 | 5 | 7 | 1 |
+------+------+------+------+------+
I would like to translate those numerical values back to a SQL-statement like the following example:
+------+-----------+------+-----------+------+-----------+------+-----------+------+-----------+
| Col1 | Col1Trans | Col2 | Col2Trans | Col3 | Col3Trans | Col4 | Col4Trans | Col5 | Col5Trans |
+------+-----------+------+-----------+------+-----------+------+-----------+------+-----------+
| 1 | ( | 2 | SELECT | 4 | CODE | 5 | LIKE | 1 | * |
+------+-----------+------+-----------+------+-----------+------+-----------+------+-----------+
| -1 | | 2 | SELECT | 6 | NUMBER | 4 | = | 5 | AND |
+------+-----------+------+-----------+------+-----------+------+-----------+------+-----------+
| 1 | ( | 2 | SELECT | 5 | TOOL | 7 | <> | 1 | * |
+------+-----------+------+-----------+------+-----------+------+-----------+------+-----------+
The numerical values differ in each column so I can only imagine the use of a lot of case...when statements which I doubt will be efficiënt. I don't want to create tables to hold the translation values. Are there ways to do this with arrays?
Are there any code samples to easily loop through table/columns and translate the contents of it?

Answer 1

You can use below code and add more case statement as per the requirement.
SELECT Col1
,CASE
WHEN Col1 = 1 THEN '('
ELSE '' END AS Col1Trans
,Col2
,CASE
WHEN Col2 = 2 THEN 'SELECT'
END AS Col2Trans
,Col3
,CASE
WHEN Col3 = 4 THEN 'CODE'
WHEN Col3 = 6 THEN 'NUMBER'
WHEN Col3 = 5 THEN 'TOOL'
END AS Col3Trans
,Col4
,CASE
WHEN Col4 = 5 THEN 'LIKE'
WHEN Col4 = 4 THEN '='
WHEN Col4 = 7 THEN '<>'
END AS Col4Trans
,Col5
,CASE
WHEN Col5 = 1 THEN '*'
WHEN Col5 = 5 THEN 'AND'
END AS Col5Trans

Answer 2

The best way to avoid so many case when and decode and etc is to use with as clause as following:
With col1trans (value, translation) as
(Select 1, '(' from dual union all
Select -1, null from dual),
Col2trans (value, translation) as
(Select 2, 'SELECT' from dual)
..
... till col5trans
Select m.col1, t1.translation as col1trans,
.... till m.col5, t5.translation
From your_table m join col1trans t1 m.col1=t1.value
join col2trans t2 m.col2=t2.value
... till col5trans
Cheers!!