How to connect to Azure Data Catalog Data from Google Apps Script

Google Apps Script gives you the ability to create custom functionality within your Google documents, including Google Sheets, Google Docs, and more. With CData Connect Server, you get a SQL Server interface for any of the 200+ sources supported by CData, including Azure Data Catalog. The SQL Server protocol is natively supported through the JDBC service in Google Apps Script, so by utilizing Connect Server, you gain access to live Azure Data Catalog data within your Google documents.

This article shows how to create a virtual database for Azure Data Catalog in Connect Server and provides sample scripting for processing Azure Data Catalog data in a Google Spreadsheet.

CData Connect Server provides a pure SQL Server interface for Azure Data Catalog, allowing you to easily build reports from live Azure Data Catalog data in Apps Script — without replicating the data to a natively supported database. As you build visualizations, Apps Script generates SQL queries to gather data. Using optimized data processing out of the box, CData Connect Server pushes all supported SQL operations (filters, JOINs, etc) directly to Azure Data Catalog, leveraging server-side processing to quickly return the requested Azure Data Catalog data.

Create a Virtual SQL Server Database for Azure Data Catalog Data

CData Connect Server uses a straightforward, point-and-click interface to connect to data sources and generate APIs.

1. Login to Connect Server and click Connections.
2. Select "Azure Data Catalog" from Available Data Sources.
3. Enter the necessary authentication properties to connect to Azure Data Catalog.

   You can optionally set the following to read the different catalog data returned from Azure Data Catalog.

   CatalogName: Set this to the CatalogName associated with your Azure Data Catalog. To get your Catalog name, navigate to your Azure Portal home page > Data Catalog > Catalog Name

   Connect Using OAuth Authentication

   You must use OAuth to authenticate with Azure Data Catalog. OAuth requires the authenticating user to interact with Azure Data Catalog using the browser. For more information, refer to the OAuth section in the help documentation.

4. Click Save Changes
5. Click Privileges -> Add and add the new user (or an existing user) with the appropriate permissions.

With the virtual database created, you are ready to connect to Azure Data Catalog data from Apps Script.

Connect to Azure Data Catalog Data with Apps Script

At this point, you should have configured a virtual database for Azure Data Catalog in Connect Server. All that is left now is to use Google Apps Script to access Connect Server and work with your Azure Data Catalog data in Google Sheets.

In this section, you will create a script (with a menu option to call the script) to populate a spreadsheet with Azure Data Catalog data. We have created a sample script and explained the different parts. You can view the raw script at the end of the article.

1. Create an Empty Script

To create a script for your Google Sheet, click Tools Script editor from the Google Sheets menu:

2. Declare Class Variables

Create a handful of class variables to be available for any functions created in the script.

//replace the variables in this block with real values as needed
var address = 'CONNECT_SERVER_URL:port';
var user = 'CONNECT_USER';
var userPwd = 'CONNECT_PASSWORD';
var db = 'azuredatacatalogdb';
var serverSslCert = '-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----';
var clientSslCert = '-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----';
var clientSslKey  = '-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----';

var dbUrl = 'jdbc:sqlserver://' + address + '/' + db + '?useSSL=true';

3. Add a Menu Option

This function adds a menu option to your Google Sheet, allowing you to use the UI to call your function.

function onOpen() {
  var spreadsheet = SpreadsheetApp.getActive();
  var menuItems = [
    {name: 'Write data to a sheet', functionName: 'connectToAzureDataCatalogData'}
  ];
  spreadsheet.addMenu('Azure Data Catalog Data', menuItems);
} 

4. Write a Helper Function

This function is used to find the first empty row in a spreadsheet.

/*
 * Finds the first empty row in a spreadsheet by scanning an array of columns
 * @return The row number of the first empty row.
 */
function getFirstEmptyRowByColumnArray(spreadSheet, column) {
  var column = spreadSheet.getRange(column + ":" + column);
  var values = column.getValues(); // get all data in one call
  var ct = 0;
  while ( values[ct] && values[ct][0] != "" ) {
    ct++;
  }
  return (ct+1);
}

5. Write a Function to Write Azure Data Catalog Data to a Spreadsheet

The function below writes the Azure Data Catalog data, using the Google Apps Script JDBC functionality to connect to Connect Server, SELECT data, and populate a spreadsheet. When the script is run, two input boxes will appear:

The first one asks the user to input the name of a sheet to hold the data (if the spreadsheet does not exist, the function creates it).

The second asks the user to input the name of a Azure Data Catalog table to read. If an invalid table is chosen, an error message appears and the function is exited.

Note, while the function is designed for use as a menu option, you can extend it for use as a spreadsheet formula.

/*
 * Reads data from a specified Azure Data Catalog 'table' and writes it to the specified sheet.
 *    (If the specified sheet does not exist, it is created.)
 */
function connectToAzureDataCatalogData() {
  var thisWorkbook = SpreadsheetApp.getActive();

  //select a sheet and create it if it does not exist
  var selectedSheet = Browser.inputBox('Which sheet would you like the data to post to?',Browser.Buttons.OK_CANCEL);
  if (selectedSheet == 'cancel')
    return;

  if (thisWorkbook.getSheetByName(selectedSheet) == null)
    thisWorkbook.insertSheet(selectedSheet);
  var resultSheet = thisWorkbook.getSheetByName(selectedSheet);
  var rowNum = 2;

  //select a Azure Data Catalog 'table'
  var table = Browser.inputBox('Which table would you like to pull data from?',Browser.Buttons.OK_CANCEL);
  if (table == 'cancel')
    return;

  var conn = Jdbc.getConnection(dbUrl, {
    user: user, 
    password: userPwd, 
    _serverSslCertificate: serverSslCert,
    _clientSslCertificate: clientSslCert,
    _clientSslKey:         clientSslKey
  );

  //confirm that var table is a valid table/view
  var dbMetaData = conn.getMetaData();
  var tableSet = dbMetaData.getTables(null, null, table, null);
  var validTable = false;
  while (tableSet.next()) {
    var tempTable = tableSet.getString(3);
    if (table.toUpperCase() == tempTable.toUpperCase()){
      table = tempTable;
      validTable = true;
      break;
    }
  } 
  tableSet.close();
  if (!validTable) {
    Browser.msgBox("Invalid table name: " + table, Browser.Buttons.OK);
    return;
  }

  var stmt = conn.createStatement();

  var results = stmt.executeQuery('SELECT * FROM ' + table);
  var rsmd = results.getMetaData();
  var numCols = rsmd.getColumnCount();

  //if the sheet is empty, populate the first row with the headers
  var firstEmptyRow = getFirstEmptyRowByColumnArray(resultSheet, "A");
  if (firstEmptyRow == 1) {
    //collect column names
    var headers = new Array(new Array(numCols));
    for (var col = 0; col < numCols; col++){
      headers[0][col] = rsmd.getColumnName(col+1);
    }
    resultSheet.getRange(1, 1, headers.length, headers[0].length).setValues(headers);
  } else {
    rowNum = firstEmptyRow;
  }

  //write rows of Azure Data Catalog data to the sheet
  var values = new Array(new Array(numCols));
  while (results.next()) {
    for (var col = 0; col < numCols; col++) {
      values[0][col] = results.getString(col + 1);
    }
    resultSheet.getRange(rowNum, 1, 1, numCols).setValues(values);
    rowNum++;
  }

  results.close();
  stmt.close();
}
  

When the function is completed, you have a spreadsheet populated with your Azure Data Catalog data, and you can now leverage all of the calculating, graphing, and charting functionality of Google Sheets anywhere you have access to the Internet.

Complete Google Apps Script

//replace the variables in this block with real values as needed
var address = 'CONNECT_SERVER_URL:port';
var user = 'CONNECT_USER';
var userPwd = 'CONNECT_PASSWORD';
var db = 'azuredatacatalogdb';
var serverSslCert = '-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----';
var clientSslCert = '-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----';
var clientSslKey  = '-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----';

var dbUrl = 'jdbc:sqlserver://' + address + '/' + db + '?useSSL=true';

function onOpen() {
  var spreadsheet = SpreadsheetApp.getActive();
  var menuItems = [
    {name: 'Write table data to a sheet', functionName: 'connectToAzureDataCatalogData'}
  ];
  spreadsheet.addMenu('Azure Data Catalog Data', menuItems);
}

/*
 * Finds the first empty row in a spreadsheet by scanning an array of columns
 * @return The row number of the first empty row.
 */
function getFirstEmptyRowByColumnArray(spreadSheet, column) {
  var column = spreadSheet.getRange(column + ":" + column);
  var values = column.getValues(); // get all data in one call
  var ct = 0;
  while ( values[ct] && values[ct][0] != "" ) {
    ct++;
  }
  return (ct+1);
}

/*
 * Reads data from a specified 'table' and writes it to the specified sheet.
 *    (If the specified sheet does not exist, it is created.)
 */
function connectToAzureDataCatalogData() {
  var thisWorkbook = SpreadsheetApp.getActive();

  //select a sheet and create it if it does not exist
  var selectedSheet = Browser.inputBox('Which sheet would you like the data to post to?',Browser.Buttons.OK_CANCEL);
  if (selectedSheet == 'cancel')
    return;

  if (thisWorkbook.getSheetByName(selectedSheet) == null)
    thisWorkbook.insertSheet(selectedSheet);
  var resultSheet = thisWorkbook.getSheetByName(selectedSheet);
  var rowNum = 2;

  //select a Azure Data Catalog 'table'
  var table = Browser.inputBox('Which table would you like to pull data from?',Browser.Buttons.OK_CANCEL);
  if (table == 'cancel')
    return;

  var conn = Jdbc.getConnection(dbUrl, {
    user: user, 
    password: userPwd, 
    _serverSslCertificate: serverSslCert,
    _clientSslCertificate: clientSslCert,
    _clientSslKey:         clientSslKey
  );

  //confirm that var table is a valid table/view
  var dbMetaData = conn.getMetaData();
  var tableSet = dbMetaData.getTables(null, null, table, null);
  var validTable = false;
  while (tableSet.next()) {
    var tempTable = tableSet.getString(3);
    if (table.toUpperCase() == tempTable.toUpperCase()){
      table = tempTable;
      validTable = true;
      break;
    }
  } 
  tableSet.close();
  if (!validTable) {
    Browser.msgBox("Invalid table name: " + table, Browser.Buttons.OK);
    return;
  }

  var stmt = conn.createStatement();

  var results = stmt.executeQuery('SELECT * FROM ' + table);
  var rsmd = results.getMetaData();
  var numCols = rsmd.getColumnCount();

  //if the sheet is empty, populate the first row with the headers
  var firstEmptyRow = getFirstEmptyRowByColumnArray(resultSheet, "A");
  if (firstEmptyRow == 1) {
    //collect column names
    var headers = new Array(new Array(numCols));
    for (var col = 0; col < numCols; col++){
      headers[0][col] = rsmd.getColumnName(col+1);
    }
    resultSheet.getRange(1, 1, headers.length, headers[0].length).setValues(headers);
  } else {
    rowNum = firstEmptyRow;
  }

  //write rows of Azure Data Catalog data to the sheet
  var values = new Array(new Array(numCols));
  while (results.next()) {
    for (var col = 0; col < numCols; col++) {
      values[0][col] = results.getString(col + 1);
    }
    resultSheet.getRange(rowNum, 1, 1, numCols).setValues(values);
    rowNum++;
  }

  results.close();
  stmt.close();
}