Assembling parameters into UltraLite connection strings

An assembly of connection parameters supplied in any application's connection code (be it an administration tool or a custom UltraLite application) is called a connection string. In some cases, applications parse the fields of a ConnectionParms object into a string. In others, you type a connection string on a single line with the parameter names and values separated by semicolons:

parameter1=value1;parameter2=value2

The UltraLite runtime ensures that the parameters are assembled into a connection string before establishing a connection with it. For example, if you use the ulload utility, the following connection string is used to load new XML data into an existing database. You cannot connect to the named database file until you supply this string:

ulload -c "DBF=sample.udb;UID=DBA;PWD=sql" sample.xml

UltraLite generates an error when it encounters an unrecognized connection parameters.

Precedence of connection parameters for UltraLite administration tools

All of the UltraLite administration tools follow a specific order of connection parameter precedence:

  • If specified, the CE_FILE, NT_FILE, and PALM_FILE parameters always take precedence over DBF.
  • If you specify two DBF parameters, the last one specified takes precedence.
  • If you supply duplicate parameters in a connection string, the last one supplied is used. All others are ignored.

  • Parameters in the connection string take precedence over those supplied in the ULSQLCONNECT environment variable or a connection object.
  • The ULSQLCONNECT environment variable is checked for connection parameters that are not supplied in the connection string.
  • If no value is supplied for both UID and PWD in either the connection string or ULSQLCONNECT, the defaults of UID=DBA and PWD=sql are assumed.
Limitations

Any leading and/or trailing spaces in connection string parameter values are ignored. Connection parameter values cannot include leading single quotes ('), leading double quotes ("), or semicolons (;).

See also

Specifying file paths in an UltraLite connection parameter