Primary key Dialog v9
Use the Primary key
dialog to create or modify a primary key constraint. A primary key constraint indicates that a column, or group of columns, uniquely identifies rows in a table. This requires that the values in the selected column(s) be both unique and not null.
The Primary key
dialog organizes the development of a primary key constraint through the General
and Definition
tabs. The SQL
tab displays the SQL code generated by dialog selections.
Use the fields in the General
tab to identify the primary key:
- Use the
Name
field to add a descriptive name for the primary key constraint. The name will be displayed in theBrowser
tree control.
Click the Definition
tab to continue.
Use the fields in the Definition
tab to define the primary key constraint:
- Click inside the
Columns
field and select one or more column names from the drop-down listbox. To delete a selection, click thex
to the left of the column name. The primary key constraint should be different from any unique constraint defined for the same table; the selected column(s) for the constraints must be distinct. - Use
Include columns
field to specify columns forINCLUDE
clause of the index. This option is available in Postgres 11 and later. - Select the name of the tablespace in which the primary key constraint will reside from the drop-down listbox in the
Tablespace
field. - Select the name of an index from the drop-down listbox in the
Index
field. This field is optional. Adding a primary key will automatically create a unique B-tree index on the column or group of columns listed in the primary key, and will force the column(s) to be marked NOT NULL. - Use the
Fill Factor
field to specify a fill factor for the table and index. The fill factor for a table is a percentage between 10 and 100. 100 (complete packing) is the default. - Move the
Deferrable?
switch to theYes
position to specify the timing of the constraint is deferrable and can be postponed until the end of the statement. The default isNo
. - If enabled, move the
Deferred?
switch to theYes
position to specify the timing of the constraint is deferred to the end of the statement. The default isNo
.
Click the SQL
tab to continue.
Your entries in the Primary key
dialog generate a SQL command (see an example below). Use the SQL
tab for review; revisit or switch tabs to make any changes to the SQL command.
Example
The following is an example of the sql command generated by user selections in the Primary key
dialog:
The example shown demonstrates creating a primary key constraint named dept_pkey
on the dept_id
column of the dept
table.
- Click the
Info
button (i) to access online help. View context-sensitive help in theTabbed browser
, where a new tab displays the PostgreSQL core documentation. - Click the
Save
button to save work. - Click the
Cancel
button to exit without saving work. - Click the
Reset
button to restore configuration parameters.