Connecting to a PostgreSQL database

This guide describes how to connect to a PostgreSQL database using Flexmonster Data Server.

The Data Server is an installable, server-side application by Flexmonster. It aggregates your data and then passes it to Flexmonster Pivot in a ready-to-show format.

See other ways of connecting to a database.

Prerequisites

Flexmonster CLI
Install it with the following command:
```
npm install -g flexmonster-cli
```

Connecting to the database

Step 1. Install Flexmonster Data Server

Get the Data Server with the flexmonster add fds command:

flexmonster add fds -r

This command installs and runs the Data Server as a Windows/Unix service. Besides, the command installs Flexmonster Admin Panel — a graphical user interface for the Data Server.

The Data Server's files can be found in the flexmonster-data-server/ folder in your working directory.

There are also alternative ways to install the Data Server:

Step 2. Add a new index

Now let's create a new index for your data.

Open Flexmonster Admin Panel and go to Indexes > Add New Index. Then, fill in the following fields:

Name. This field defines the index name. It will be used to configure the connection on the client side.
Type. This dropdown menu contains possible data source types. In this case, select Database.
Database type. In this case, select PostgreSQL.
Connection string. Specify the connection string to your database here. Check out examples of different connection strings for PostgreSQL.
Click Test to check whether the provided connection string is correct.
Note About passwords with special characters in the connection string: the Data Server parses such passwords correctly unless the password contains ; or ". These symbols are treated as delimiters, so if your password contains them, enclose it in single quotes (e.g., Pwd='123;"45').
Query. Specify an SQL query to define the subset of data that the Data Server should fetch. The Query can contain a stored procedure.
Refresh time. Defines how often the Data Server should reload the data from the database. The refresh time should be specified in minutes.
By default, the refresh time is 0, which means the Data Server will not reload the data.

Your configurations should look similar to the following:

Sample configuration of a PostgreSQL index

When the index configuration is complete, click Create. The index will be automatically added to your index pool.

Step 3. Embed the component into your webpage

If Flexmonster is not yet embedded, set up an empty component in your webpage:

In pure JavaScript

Complete the Integrating Flexmonster guide. Your code should look similar to the following example:

const pivot = new Flexmonster({
  container: "pivotContainer",
  toolbar: true
});

In React

Complete the Integration with React guide. Your code should look similar to the following example:

<FlexmonsterReact.Pivot
 toolbar={true}
/>

In Angular

Complete the Integration with Angular guide. Your code should look similar to the following example:

<fm-pivot
 [toolbar]="true">
</fm-pivot>

In Vue

Complete the Integration with Vue guide. Your code should look similar to the following example:

<Pivot
 toolbar
/>

Step 4. Configure the report

The report should be configured as follows:

const pivot = new Flexmonster({
  container: "pivotContainer",
  toolbar: true,
  report: {
    dataSource: {
      type: "api",
      url: "http://localhost:9500",
      index: "index-database"
    }
  }
});

Note The index must match the name of the index defined in step 2 (e.g., "index-database").

To configure the dataSource object, check out the list of supported configuration parameters.

List of supported configuration parameters

When connecting to data from the database, you can use the following properties to configure the DataSourceObject:

List of properties

Property/Type	Description
type String	The data source type. When connecting to data from the database, set the `type` to `"api"`.
url String	The URL to Flexmonster Data Server.
index String	The dataset index.
mapping MappingObject \| String	optional Defines how fields from the data source are treated and presented within the component. For example, you can specify the field’s captions, define a type for a field, configure multilevel hierarchies, etc. Read more in the Mapping guide. It can be either an inline MappingObject or a URL to a JSON file with the mapping Live example.
requestHeaders Object	optional Adds custom request headers. Consists of `"key": "value"` pairs, where `"key"` is a header name and `"value"` is its value Live example. Note The `requestHeaders` property is not saved when obtaining the report via `save()` and `getReport()` API calls.
singleendpoint Boolean	optional When set to `true`, all custom data source API requests are sent to a single endpoint specified in the url property. Default value: `false`.
withCredentials Boolean	optional Indicates whether cross-site `Access-Control` requests should be made using credentials such as authorization headers (`true`) or not (`false`). For more details, refer to MDN web docs. Setting the `withCredentials` flag to `true` is recommended when using Windows authentication and other types of server authentication. When set to `false`, the browser does not ask for credentials and does not include them in outgoing requests. Default value: `false`.
concurrentRequests Boolean	optional When set to `false`, Flexmonster sends a request for each expand/drill-down separately and waits for the server’s response before sending a new request. This can result in slow performance when there are a lot of expands/drill-downs in the report. When the `concurrentRequests` is `true`, Flexmonster sends requests for expands/drill-downs of a particular level simultaneously. To get the best performance, enable the HTTP/2 protocol in the Data Server. Default value: `false`.

Display non-Latin characters correctly

If your data contains non-Latin characters, ensure you have set UTF-8 encoding for your data and page. This is required to display the data correctly in the component.

About response caching

When Flexmonster Pivot requests data, Flexmonster Data Server sends a response and then caches it. If the component sends the same request again, the server responds with the data from its cache.

The Data Server’s cache has a limit. When the cache does not have enough space for a new response, the Data Server deletes one of the previously cached responses. See how to manage the cache size for the Data Server as a service, as a console application, or as a DLL.

The Data Server clears the cache when restarted.

Calling a stored procedure

Follow the steps below to call a stored procedure in the Data Server:

Step 1. Create a stored procedure.

Step 2. When adding a new index, call the stored procedure in the Query field:

call storedProcedure()

Learn more about calling stored procedures in PostgreSQL.

Note With stored procedures, you can execute any valid SQL query from the Data Server. To avoid unauthorized access to the database, create a database user with read-only access rights and specify this user in the connection string.

Changes to Flexmonster Software License Agreement