Query a public dataset with the BigQuery C# client library

Open the Cloud Shell Editor

1. In Cloud Shell, create a new C# project and file:

    dotnet  
   new  
   console  
   -n  
   BigQueryCsharpDemo 
   

   The output is similar to the following. Several lines are omitted to simplify the output.

    Welcome to .NET 6.0!
   ---------------------
   SDK Version: 6.0.407
   ...
   The template "Console App" was created successfully.
   ... 
   

   This command creates a C# project that's named BigQueryCsharpDemo and a file that's named Program.cs .

2. Open the Cloud Shell Editor:

    cloudshell  
   workspace  
   BigQueryCsharpDemo 
   

To learn how to prepare files for queries, click Next.

Prepare files for queries

1. To open a terminal in the Cloud Shell Editor, click Open Terminal.

2. Open your project directory:

     cd 
     
   BigQueryCsharpDemo 
   

3. Install the BigQuery client library for C#:

    dotnet  
   add  
   package  
   Google.Cloud.BigQuery.V2 
   

   The output is similar to the following. Several lines are omitted to simplify the output.

    Determining projects to restore...
   Writing /tmp/tmpF7EKSd.tmp
   ...
   info : Writing assets file to disk.
   ... 
   

To learn how to query a public dataset in BigQuery, click Next.

Query a public dataset in BigQuery

1. Set the variable GOOGLE_PROJECT_ID to the value GOOGLE_CLOUD_PROJECT and export the variable:

     export 
     
    GOOGLE_PROJECT_ID 
    = 
    $GOOGLE_CLOUD_PROJECT 
    
   

2. Click Open Editor.

3. In the Explorerpane, locate your BIGQUERYCSHARPDEMO project.

4. Click the Program.cs file to open it.

5. To create a query against the bigquery-public-data.stackoverflow dataset that returns the top 10 most viewed Stack Overflow pages and their view counts, replace the contents of the file with the following code:

     using 
     
    System 
    ; 
    using 
     
     Google.Cloud.BigQuery.V2 
    
    ; 
    namespace 
     
    GoogleCloudSamples 
    { 
     
    public 
     
    class 
     
    Program 
     
    { 
     
    public 
     
    static 
     
    void 
     
    Main 
    ( 
    string 
    [] 
     
    args 
    ) 
     
    { 
     
    string 
     
    projectId 
     
    = 
     
    Environment 
    . 
    GetEnvironmentVariable 
    ( 
    "GOOGLE_PROJECT_ID" 
    ); 
     
    var 
     
    client 
     
    = 
     
     BigQueryClient 
    
    . 
     Create 
    
    ( 
    projectId 
    ); 
     
    string 
     
    query 
     
    = 
     
    @"SELECT 
    CONCAT( 
    'https://stackoverflow.com/questions/', 
    CAST(id as STRING)) as url, view_count 
    FROM `bigquery-public-data.stackoverflow.posts_questions` 
    WHERE tags like '%google-bigquery%' 
    ORDER BY view_count DESC 
    LIMIT 10" 
    ; 
     
    var 
     
    result 
     
    = 
     
    client 
    . 
     ExecuteQuery 
    
    ( 
    query 
    , 
     
    parameters 
    : 
     
    null 
    ); 
     
    Console 
    . 
    Write 
    ( 
    "\nQuery Results:\n------------\n" 
    ); 
     
    foreach 
     
    ( 
    var 
     
    row 
     
    in 
     
    result 
    ) 
     
    { 
     
    Console 
    . 
    WriteLine 
    ( 
    $"{row[" 
    url 
    "]}: {row[" 
    view_count 
    "]} views" 
    ); 
     
    } 
     
    } 
     
    } 
    }