Presentation on theme: "Obtain Data from Other Sources Data you need to include in an Access database often already exists in another file: in another Access database, in a table."— Presentation transcript:
Obtain Data from Other Sources Data you need to include in an Access database often already exists in another file: in another Access database, in a table in a non-Access database such as Paradox or dBASE, in a spreadsheet such as Excel or Lotus, in a text file, in an HTML table, or in a file created by any program that allows its data to be presented in tabular form. You can include this data in your Access database in one of three ways: Copy and paste the data Import the data Link to the data
You can copy and paste data from one table into another table only if the two tables have the same structure. That is, the tables must contain the same fields in the same order. You’d use this method if you’ve already created a table and need to add records to it that already exist in some other table. Copy and Paste the Data
When you import data, your Access database gets its own copy of the imported data as a new table in the database; the original table or file is not changed or deleted. When you want your Access database to include an entire table (i.e. the table design, all the field properties, and all data values) that already exists elsewhere, you should import that table. Import the Data
Link to the Data When you link to data, only a link or connection to that data is stored in the Access database. The actual data itself is not stored within the database. When you want the Access database to always have the current version of data that can be updated by another program, you should link to that data.
Comparing the Methods When you either copy and paste data or import data, you receive the data as it exists at that moment. If the original data is subsequently changed, that change is not reflected in the imported or copied data in the Access database. Likewise, if the imported or copied data within the Access database is changed, that change is not reflected in the original data. In contrast, when you link to data, the data itself still exists only its original location. The linked data can be updated (added, deleted, or changed) either in the original program or in the Access database, and all programs that use that data will see the changes.
When you copy and paste, the data is inserted in an existing structure in your database. In contrast, when you import data, the data and the structure that contains that data are inserted into your database. Access works faster with copied or imported data than it does with linked data. So if you don’t require the update capabilities of the original source, you should either copy and paste or import data rather than link to it. Comparing the Methods