Data Type Synonyms¶
Data type synonyms are included in SQL Server for ISO compatibility. Data type synonyms can be used instead of the corresponding base data type name in data definition language (DDL) statements, such DECLARE @variable, CREATE TABLE or CREATE FUNCTION. However, after the object is created, the synonyms have no visibility. When the object is created, the object is assigned the base data type that is associated with the synonym, instead of the synonym itself. There is no trail that the synonym was used in the statement that created the object.
| Synonym | SQL Server System Base Data Type |
|---|---|
| binary varying | varbinary |
| char varying | varchar |
| character | char |
| character | char(1) |
| character(n) | char(n) |
| character varying(n) | varchar(n) |
| dec | decimal |
| double precision | float |
| float[(n)] for n=1 to 7 | real |
| float[(n)] for n=8 to 15 | float |
| integer | int |
| national character(n) | nchar(n) |
| national char(n) | nchar(n) |
| national character varying(n) | nvarchar(n) |
| national char varying(n) | nvarchar(n) |
| national text | ntext |
| timestamp | rowversion |