Technical Reference Manual - InduSoft

Database Interface
Because the provider is only installed on the device and not on your development workstation, you cannot
select it in the Data Link Properties dialog when you develop your project. Instead, you must manually enter
the connection string using the following format:
Version
SQL CE 2.0
SQL CE 3.0
SQL CE 3.5
Connection String
Provider=SQLCE; Data Source=database_path
Provider=SQL_CE3.0; Data
Source=database_path
Provider=SQL_CE3.5; Data
Source=database_path
Examples:
Note: The database interface was fully tested with these versions of SQL CE. However, other
versions might also be supported; please contact Customer Support for more information.
• Access a database file at the fixed location \Harddisk\MyDatabase.sdf:
Provider=SQLCE; Data Source=\Harddisk\MyDatabase.sdf
The exact path depends on how your device's non-volatile memory is organized. Please consult the
manufacturer's documentation.
• Access a database file at the location specified by the String tag DatabaseFile:
Provider=SQLCE; Data Source={DatabaseFile}
The curly brackets ({}) indicate that it's a tag reference.
Please keep in mind that SQL CE is only intended for lightweight databases and simple transactions. It
cannot efficiently handle large amounts of data, such as the Alarm and Event histories. In those cases, we
recommend that you either use the Proprietary history format or use a more powerful relational database like
the full version of Microsoft SQL Server. If you must use SQL CE, then we recommend that you use it only as
a Secondary database with the Store and Forward option selected. For more information, see Saving your alarm
history / event log to an external database.
Caution: When using a Database worksheet or the DB/ERP functions to access a SQL CE
database, remember…
• Column/field names must match exactly or the database commands will fail; and
• IWS data types will be converted into possibly unexpected SQL data types. The following table
shows how they're converted:
IWS
Boolean
Integer
Real
String
SQL CE
int
int
real
nvarchar
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