Import and Export

To share your records with other databases MUIbase offers a way to import and export records to and from other databases. Import and export is done by reading and writing ASCII files. Therefore the data you want to import must be in a special format described in the following section.

File format

For importing records into MUIbase all records of a table must be available in a single ASCII file. If you want to import records of several tables you must have several import files, one for each table.

An import file consists of lines and columns. Lines are separated by a record delimiter, columns by a field delimiter. The delimiters can be specified in the import and export requesters. As the record fields itself may already contain these delimiters it is possible to use double quotes around all fields to protect them.

The import file must have the following structure:

• The first line contains the field names. For each name there must be an attribute with exactly the same name in the table where the records are imported to. If there is a name where no matching attribute can be found, an error message is generated.
• The following lines contain one record each. As all fields must be given as ASCII strings they are automatically converted to the type of the destination attribute. For attributes of type boolean, the field must be either NIL or TRUE (case insensitive), otherwise an error message is generated. For attributes of type choice the exact label string must be specified (case sensitive). For reference attributes you have to specify the record number starting with 1. For all other types a value of NIL is used if the field cannot be converted to the required type.
• If you decide to use double quotes then all record fields including the line with the field names must be surrounded by double quotes.

Sample import file

The following sample import file uses \n and \t as record and field delimiter and double quotes around all fields. The file can be imported into a table with the following attributes:

• Name (string)
• NumChildrens (integer)
• Feminine (bool)
• Job (choice)
• Notes (memo)

"Name"	"NumChildrens"	"Feminine"	"Job"	"Notes"
"Janet Jackson"	"???"	"TRUE"	"Musician"	"Latest CD: The velvet rope"
"Bernt Schiele"	"???"	"NIL"	"Scientist"	"Research interests:
Robotics, Autonomy and Computer Vision"
"Gerhard"	"0"	"NIL"	"Precision mechanic"	""

Importing records

To import records into the active table select menu item `Table - Import records'. This will open a window containing

• a string field for entering the import filename. Right to this field you find three buttons. Click on the first one to open a file requester for choosing the filename. The `V' button starts an external viewer to view the entered filename, and the `E' button starts an editor to edit the file contents.
• two string fields for entering the record and field delimiter. You can enter a single character here or an escape code by typing \n, \t, \f, \??? (octal code), or \x?? (hex code).
• a field `Double quotes' that can be checked to specify that the fields are surrounded by double quotes.
• two buttons `Import' and `Cancel' for leaving the window.

If you press the `Import' button, MUIbase will load the specified file and import all found records. If everything is going fine, MUIbase will ask you after the import process if you really want to add the imported records to the table. At this point you can still cancel the operation.

If an error occurs while reading the import file then an error message is generated.

If you need a more sophisticated import routine it is recommended to write your own import routine as a MUIbase program.

Exporting records

To export records from the active table select menu item `Table - Export records'. This will open a window containing

• a string field for entering the export filename. Right to this field you find a pop-up button to open a file requester for choosing the filename.
• two string fields for entering the record and field delimiter. You can enter a single character here or an escape code by typing \n, \t, \f, \??? (octal code), or \x?? (hex code).
• a field `Double quotes' that can be checked to specify that the fields should be surrounded by double quotes.
• a field `Filter'. If checked only the records that match the currently installed record filter are written to the export file.
• two buttons `Export' and `Cancel' for leaving the window.

After you pressed the `Export' button, MUIbase will open the specified file and write out the records including a header line containing the attribute names. The export feature always writes all attribute fields of a table to the export file.

For a more customized export routine, you can use MUIbase' query editor (see section Data retrieval) or you write your own export function as a MUIbase program.

Go to the first, previous, next, last section, table of contents.