Non identifying relationship database in excel

Tutorial: Extend Data Model relationships using Excel, Power Pivot, and DAX - Excel

non identifying relationship database in excel

Excel's Data Model feature allows you to build relationships between data sets Excel will identify those tables as a Data Model Table, not a. DB Reverse and Entity-import via Excel are available by using free Plug-ins. Non-Identifying Relationship or Many-tomany Relationships from the Tool palette . Creating a relational database starts with a Master table that links to One spreadsheet, alone, is a database, but not a relational one. additional information that's related to the individual drivers (identified by the unique key.

In Excel, click the Hosts tab to make it the active sheet. This step adds the Hosts table to the Data Model. It also opens the Power Pivot add-in, which you use to perform the remaining steps in this task. Notice that the Power Pivot window shows all the tables in the model, including Hosts. Click through a couple of tables. Use the slide bar to resize the diagram so that you can see all objects in the diagram. Notice that four tables are unrelated to the rest of the tables: You notice that both the Medals table and the Events table have a field called DisciplineEvent.

Upon further inspection, you determine that the DisciplineEvent field in the Events table consists of unique, non-repeated values.

  • Difference between Identifying and Non-Identifying Relationships
  • Relationships between tables in a Data Model
  • Tutorial: Extend Data Model relationships using Excel, Power Pivot, and DAX

The DisciplineEvent field represents a unique combination of each Discipline and Event. In the Medals table, however, the DisciplineEvent field repeats many times. Create a relationship between the Medals table and the Events table. A line appears between them, indicating a relationship has been established. Click the line that connects Events and Medals. The highlighted fields define the relationship, as shown in the following screen.

To connect Hosts to the Data Model, we need a field with values that uniquely identify each row in the Hosts table. Then we can search our Data Model to see if that same data exists in another table. With Hosts selected, switch back to Data View. Extend the Data Model using calculated columns To establish a relationship between the Hosts table and the Data Model, and thereby extend our Data Model to include the Hosts table, Hosts must have a field that uniquely identifies each row.

In addition, that field must correspond to a field in the Data Model. You can, however, create new columns by using calculated fields based on the existing data.

By looking through the Hosts table, then looking at other Data Model tables, we find a good candidate for a unique field we could create in Hosts, and then associate with a table in the Data Model.

Both tables will require a new, calculated column in order to meet the requirements necessary to establish a relationship. In Hosts, we can create a unique calculated column by combining the Edition field the year of the Olympics event and the Season field Summer or Winter. In the Medals table there is also an Edition field and a Season field, so if we create a calculated column in each of those tables that combines the Edition and Season fields, we can establish a relationship between Hosts and Medals.

The goal is to create a calculated column in the Hosts table, and then in the Medals table, which can be used to establish a relationship between them. Select the Hosts table in Power Pivot.

Adjacent to the existing columns is an empty column titled Add Column. Power Pivot provides that column as a placeholder. There are many ways to add a new column to a table in Power Pivot, one of which is to simply select the empty column that has the title Add Column.

In the formula bar, type the following DAX formula. As you type, AutoComplete helps you type the fully qualified names of columns and tables, and lists the functions that are available. Use tab to select AutoComplete suggestions. You can also just click the column while typing your formula, and Power Pivot inserts the column name into your formula. Values are populated for all the rows in the calculated column. Such fields are called a primary key.

You can rename any column by double-clicking it, or by right-clicking the column and choosing Rename Column. When completed, the Hosts table in Power Pivot looks like the following screen. The Hosts table is ready. Start by creating a new column in the Medals table, like we did for Hosts.

How to use Excel's Data Model to turn related data into meaningful information

Notice that Add Column is selected. This has the same effect as simply selecting Add Column. The Edition column in Medals has a different format than the Edition column in Hosts. Before we combine, or concatenate, the Edition column with the Season column to create the EditionID column, we need to create an intermediary field that gets Edition into the right format.

Defining Identifying and Non-Identifying Relationships in Vertabelo

In the formula bar above the table, type the following DAX formula. Values are populated for all the rows in the calculated column, based on the formula you entered. Rename the column by right-clicking CalculatedColumn1 and selecting Rename Column.

Type Year, and then press Enter.

non identifying relationship database in excel

When you created a new column, Power Pivot added another placeholder column called Add Column. In the formula bar, type the following DAX formula and press Enter. Sort the column in ascending order.

The Medals table in Power Pivot now looks like the following screen.

Database Lesson #4 of 8 - Data Modeling and the ER Model

Notice many values are repeated in the Medals table EditionID field. What is unique in the Medals table is each awarded medal. The unique identifier for each record in the Medals table, and its designated primary key, is the MedalKey field. The next step is to create a relationship between Hosts and Medals. You can also switch between Grid view and Diagram view using the buttons at the bottom of the PowerView window, as shown in the following screen. Expand Hosts so you can view all of its fields.

We created the EditionID column to act as the Hosts table primary key unique, non-repeated fieldand created an EditionID column in the Medals table to enable establishment of a relationship between them. We need to find them both, and create a relationship.

non identifying relationship database in excel

Power Pivot provides a Find feature on the ribbon, so you can search your Data Model for corresponding fields. Position the Hosts table so that it is next to Medals. Power Pivot creates a relationship between the tables based on the EditionID column, and draws a line between the two columns, indicating the relationship. In this section, you learned a new technique for adding new columns, created a calculated column using DAX, and used that column to establish a new relationship between tables.

You can also use the associated data to create additional PivotTables, PivotCharts, Power View reports, and much more. Create a hierarchy Most Data Models include data that is inherently hierarchical. Common examples include calendar data, geographical data, and product categories.

Creating hierarchies within Power Pivot is useful because you can drag one item to a report — the hierarchy — instead of having to assemble and order the same fields over and over. The Olympics data is also hierarchical. For each sport, there is one or more associated disciplines sometimes there are many.

And for each discipline, there is one or more events again, sometimes there are many events in each discipline. In Diagram View, the active relationship is a solid line and the inactive ones are dashed lines.

If the active relationship is between DateKey and OrderDate, that is the default relationship in formulas unless you specify otherwise. A relationship can be created when the following requirements are met: Criteria Description Unique Identifier for Each Table Each table must have a single column that uniquely identifies each row in that table.

non identifying relationship database in excel

This column is often referred to as the primary key. Unique Lookup Columns The data values in the lookup column must be unique. In a Data Model, nulls and empty strings are equivalent to a blank, which is a distinct data value. Compatible Data Types The data types in the source column and lookup column must be compatible.

For more information about data types, see Data types supported in Data Models. In a Data Model, you cannot create a table relationship if the key is a composite key. Other relationship types are not supported.

ER Diagram

You can do this before you import the data, or by creating a calculated column in the Data Model using the Power Pivot add-in. However, you can use DAX functions to model many-to-many relationships.

A self-join is a recursive relationship between a table and itself. Self-joins are often used to define parent-child hierarchies.

non identifying relationship database in excel

In other words, the following set of relationships is prohibited. Automatic detection and inference of relationships in Power Pivot One of the advantages to importing data using the Power Pivot add-in is that Power Pivot can sometimes detect relationships and create new relationships in the Data Model it creates in Excel. When you import multiple tables, Power Pivot automatically detects any existing relationships among the tables.

The detection algorithm uses statistical data about the values and metadata of columns to make inferences about the probability of relationships. Data types in all related columns should be compatible. For automatic detection, only whole number and text data types are supported.

For the relationship to be successfully detected, the number of unique keys in the lookup column must be greater than the values in the table on the many side. In other words, the key column on the many side of the relationship must not contain any values that are not in the key column of the lookup table.

For example, suppose you have a table that lists products with their IDs the lookup table and a sales table that lists sales for each product the many side of the relationship.