How Empty Strings are Processed
Ingres allows empty strings such as '' (also known as zero-length strings) to be stored in character data types, which is not allowed by Oracle (see Note). Applications such as OpenROAD rely on the ability to insert a zero-length character into a char or varchar field.
Note: Oracle treats empty strings ('') as NULL.
For Oracle and Microsoft SQL Server, the gateway handles empty strings as follows:
• If an empty string is received from the client, the gateway stores it as a single blank character.
• When data is retrieved, if the data type is character and if it contains a single blank character, the gateway returns an empty string to the client.
• A zero-length character and a one-byte character that contains a single blank character appear to be treated identically.
Note: Microsoft SQL Server 7.0 added support for empty strings. However, the gateway empty string processing has not changed.
Last modified date: 08/22/2022