Restructuring a Table

Description

Once you have created a table, you can restructure it by adding, removing, or changing fields. To restructure a table, you need exclusive access to the table, which means no one else can be using the table. You restructure tables using the Table Editor, which has the same features as when creating a new table, except you cannot edit the indexes.

Adding a New Field 

  1. Display the Table/Sets tab of the Control Panel.

  2. Select the table and click Design > Table Structure.

  3. In the Restructure Table dialog enter a new field at the bottom of the list.

  4. Optionally, move the new field to a different position in the record structure.

Moving a Field 

  1. Select the field you want to move, as in the illustration below.

  2. Click a second time to change the black bar to a thin black line.

  3. Holding the cursor down, drag the black line to the location where the field should be located.

  4. Release the cursor.

Changing Field Types and Sizes 

When restructuring a table that has data in it, you must be careful to avoid data loss. Data might be lost by changing a field's definition. For example, you might lose data if you change a field's width to a smaller value. Characters that do not fit into the new width are truncated. Data might also be lost if you change a field's type, as summarized below:

Character to: 

  • Numeric 

    Converts valid numbers appearing before any other characters in the field (e.g. 100xyz is converted to 100). Retains decimal places if you specify decimal places for the numeric field. If you do not specify decimal places, values are rounded to the nearest whole number. Converts other data (including numbers with currency signs) to 0. Converting numbers with thousands separators isn't supported.

  • Date 

    Converts valid dates entered in the format MM/DD/YY, MM/DD/YYYY, MM-DD-YY, or MM-DD-YYYY appearing before any other characters in the field.

  • Logical 

    Converts the characters T, t, F, f, Y, y, N, or n appearing first in the field to a True or False value. All other characters return a False value.

  • Memo 

    Transfers all characters stored in the Character field to the Memo field.

Numeric to: 

  • Character 

    Retains all values.

  • Date 

    Converts to NULL (blank)

  • Logical 

    Converts values equaling zero to F (false). Converts values greater or less than zero to T (true).

  • Memo 

    Retains all values.

Logical to: 

Date to: 

  • Character 

    Returns values in the format YYYY/MM/DD. For example, 09/20/2001 converts to 2001/09/20.

  • Numeric 

    Converts to NULL.

  • Logical 

    Converts to NULL.

  • Memo 

    Retains all values.

Date to: 

  • Character 

    Returns values in the format YYYY/MM/DD. For example, 09/20/2001 converts to 2001/09/20.

  • Numeric 

    Converts to NULL.

  • Logical 

    Converts to NULL.

  • Memo 

    Retains all values.

Memo to: 

  • Character 

    Retains characters that fit in the field. For example, a field that's 40 characters wide accepts the first 40 characters of memo text.

  • Numeric 

    Converts valid numbers appearing before any other characters in the field. For example, 100xyz is converted to 100. Retains decimal place digits if you specify decimal places for the numeric field. Converts other data (including numbers with currency signs) to 0. Converting numbers with thousands separators isn't supported.

  • Date 

    Converts valid dates in the format MM/DD//YY, MM/DD/YYYY, MM-DD-YY, or MM-DD-YYYY appearing before any other characters.

  • RTF Memo 

    Transfers all characters stored in the Memo field to the RTF Memo field.

  • Logical 

    Converts the characters T, t, F, f, Y, y, N, or n located in the first position in the field to a True or False value. All other characters return a False value. All other values return an uppercase F.

RTF Memo to: 

  • Character 

    Retains characters that fit in the field. However, text formatting and font is not retained.

  • Numeric 

    Converts to NULL (blank).

  • Memo 

    Transfers all characters stored in the Memo field to the RTF Memo field. However, text formatting and font is not retained.

Image File Reference to: 

  • Character 

    Displays text filename and path to image. For example:

    =filename_decode("exe_folder\Samples\Alphasports\hotbar.bmp")
  • Memo 

    Displays text filename and path to image. For example:

    =filename_decode("exe_folder\Samples\Alphasports\hotbar.bmp")
Changing a field type to any of the other types (e.g. JPEG, Active X) deletes any data in the field.

See Also