WinSQL » Knowledge base
|Subject:||Can I compare schema between two different types of databases?|
|Creation date:||7/29/09 4:23 PM|
|Last modified on:||7/29/09 4:24 PM|
Comparing schema across DB types
WinSQL will allow you to compare schema between multiple database
types, for example Informix and MS SQL Server. However, there is one
important factor to keep in mind: you will most likely get a mismatch
on the data type.
WinSQL considers the following parameter when matching schema for a table.
- Field names
- Field data types
- Default value
- Foreign key relationships
You will almost always get a mismatch on the data type if the two
databases are of different type. This happens because the internal
representation of a data type is quite different from one database to
another. Consider the following scenario.
|Table in Oracle||Table in MS SQL Server
CREATE TABLE ORA_TABLE(
P_ID NUMBER(*,0) NOT NULL,
CREATE TABLE MS_SQL_TABLE(
P_ID Integer NOT NULL,
Besides, the name of the data types being different, there is a
mismatch on precision as well - meaning Oracle's NUMBER can hold up to
38 digits but SQL Server's Integer can only go up to 4294967296 (10
To avoid mismatch on data types when comparing
schema between two different types of databases, you can configure the
Schema Diff wizard to skip the data types during comparison. Refer to
the image below.
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