[Composite Datasource]: Handle Null/Empty Values in SQL

Elixir Repertoire Repertoire Designer
1

The attached User Guide shows how ’ ’ and a null value is handle in composite datasource.

Different datasources have different interpretations for EMPTY (’ ') and NULL value.

What is the differences between ’ ’ and NULL value?

  1. An ’ ’ value is a “field-formatted” value with no significant data in it.

  2. A NULL value represents the absence of a value for a record in a field.

  3. Null has no bounds; it can be used for string, integer, date, etc. fields in a database. An empty string is just regarding a string; it’s a string like ‘abcdef’ but without length.

Example on ’ ’ value:

SQL Statement:

CREATE TABLE Employee(empName VARCHAR(20), empTel VARCHAR(20), empAdd VARCHAR(20));
INSERT INTO Employee VALUES('Ken','','ABC');

Output:

Example on NULL value:

SQL Statement:

CREATE TABLE Employee(empName VARCHAR(20), empTel VARCHAR(20), empAdd VARCHAR(20));
INSERT INTO Employee VALUES('Ken',null,'ABC');

Output:

Note: It is recommended to use a Null value to indicate no data is available.

HowEmptyValueIsHandleInCMP.pdf (304.1 KB)