A foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table or the same table. In simpler words, the foreign key is defined in a second table, but it refers to the primary key in the first table.
I'm using SQL Developer but I can't seem to find which column in my table holds the foreign key to the other table. When I click on the table, a bunch of tabs show up, among which is the Constraints tab. Here, I can see the foreign key, but I don't see which columns are involved in it.
Open Constraints tab. When you click one of the foreign key constraint name, columns wihch is used in the foreign key references will be seen in the Columns view at the bottom of Constraints Tab
I have three Tableau Server data sources in a workbook that represent three tables in a database. Table A is joined to Table B and table B is joined to Table C. There is no foreign key relationship between Table A and Table C, but the implicit relationship exists through Table B (junction table). When using Table A as the primary data source on a report, I receive an error message when attempting to add data from Table C.
In order to use fields from Table C, a relationship needs to be created with Table A. Select Data > Edit Relationships to open the Relationships dialog box.
Is there any way to join multiple Tableau Server data sources to accomplish the described scenario?
Tableau has the concept of Primary and Secondary data sources, and every secondary needs to have a key into the primary to be considered. You can't link a secondary to a secondary data source.
My suggestion here would be creating another data source already joined/blended. This can be done by connecting directly to the database and joining the tables using Tableau wizard (see image below):
Or, if you feel comfortable, you can use the New Custom SQL button and use your own query (see image below):
I am new to postgreSQL. Is there any way to insert row in postgreSQL pgAdmin without using SQL Editor (SQL query)?
The accepted answer is related to PgAdmin 3 which is outdated and not supported.
For PgAdmin 4 and above, the application is running in the browser.
After you create your table, you have to make sure that your table has a primary key otherwise you couldn't edit the data as mentioned in the official documentation.
To modify the content of a table, each row in the table must be
uniquely identifiable. If the table definition does not include an OID
or a primary key, the displayed data is read only. Note that views
cannot be edited; updatable views (using rules) are not supported.
1- Add primary key
Expand your table properties by clicking on it in the pgAdmin4 legend. Right-click on 'Constraints', select 'Create' --> 'Primary Key'to define a primary key column.
2- View the data in excel like format
Browser view, right-click on your table --> select View/Edit Data --> All Rows
3- Add new row / Edit data
On the Data Output tab at the bottom of the table below the last row, there will be an empty row where you can enter new data in an excel-like manner. If you want to make updates you can also double click on any cell and change its value.
4- Save the changes
Click on the 'Save' button on the menu bar near the top of the data window.
I think some answers don't provide an answer to the original question, some of them insert records but with SQL statements and the OP clearly said WITHOUT, so I post the right answer: (Step by Step)
Alternatively you can use the query tool:
INSERT INTO public.table01(
name, age)
VALUES (?, ?);
use the lightning icon to execute.
You can do that without the SQL editor, but it's better to do this by queries.
Although, in pgAdmin, there is an option which you can click to have an excel-like window where you can add and update data in a table without using SQL language. Please select a table which you want to add a row first and click on the next icon here below.
Editing table data without primary key is forbidden
If your tables don't have a primary key or OIDs, you can view the data only.
Inserting new rows and changing existing rows isn't possible for the Edit Data tool without primary key.
Use INSERT:
INSERT INTO tablename (field1, field2) values ('value1', 2);
on pgAdmin 4, right-click on the table and use the item like below. You can also use that script in the background.
Finally, to watch the inserted data do like below. You can also use that script in the background.
All the above are correct answers. I just want to add that : When u create a table, make sure u have atleast one column as PRIMARY_KEY. Then, just follow the GUI : View/Edit data. U can add row as the last row of the table
As an update, the icon for the save button is different in pgAdmin 4.
This is how the menu should look after right-clicking on the table you want to insert into and hovering over "View/Edit Data".
After adding rows, either press F6 (on Ubuntu) or click the icon that looks like a stack of discs (database icon) with a lock on it.
Zoomed in:
Wide View:
Are there any options in MySQL Workbench to draw the relationship-line between the columns and not the tables? If i export my diagram as JPG i can't see, which columns are foreign keys and who they are related to.
On the screenshot, you can't see, that id and user_id are connected.
In the main menu bar go to: Model -> Relationship Notation -> Connect to columns.
I'm not sure MySQL Workbench can draw relationship lines between columns but you can aware that Primary Key is shown as Key Symbol and Foreign Key is shown as Red Diamond Symbol.
I'm brand new to MySQL Workbench and a have a bit of experience with databases (MS Access). I'm having trouble populating my fk with data. Here's what I have in my db schema:
2 tables Block and Set (Block having a pk Block_ID (type of INT); Set having fk to Block with fk name Set_Block_ID (type of INT).
1 to many relationship created from Block to Set tables linking Block_ID to Set_Block_ID. Relationship created, no problems
I populate the Block table with data. No problems
I then go to populate the Set table with data. I can see all my columns but not the fk. My question is why?
I have created the exact same db in MS Access and my fk is displayed in the linked table and I can populate it while MS Access makes sure referential integrity is enforced. I'm really brand new to Workbench and cant figure out why I cant see and populate my fk column.
Any help is appreciated!
Thanks!! =)
After having digested all the replies to my question (note sarcasm here) I have finally found a workaround way of solving the issue. To recap:
ISSUE:
created a simple 2 table relationship with Workbench with PK and FK (1 .. n relationship)
FK column not visible in Table Edit so not possible to enter any referencing data
SOLUTION:
installed SQLyog and connected to same server
opened same database and redid the simple 1 .. n relationship
FK column visible for editing in SQLyog
likewise, FK column visible for editing in Workbench
As I said, I'm new to this whole thing so I don't know what the problem was in Workbench. I just know it seems to be working fine now.
As you have noticed, the relationship drawing tool does not create actual foreign key constraints.
However, if double-click the referencing table and switch to the foreign-key tab, you can create references and specify the columns involved. This generates and maintains the visual linkage automatically: