Retrieving data based on user permissions

public string CreateESQ()
{
    var result = "";
    // Receiving an instance of the object schema manager.          
    EntitySchemaManager esqManager = SystemUserConnection.EntitySchemaManager;
    // Receiving an instance of the schema that will be the root schema for the created
    // EntitySchemaQuery instance.
    var rootEntitySchema = esqManager.GetInstanceByName("City") as EntitySchema;
    // Creating the EntitySchemaQuery instance that will have
    // rootEntitySchema as the root schema.
    var esqResult = new EntitySchemaQuery(rootEntitySchema);
    // Adding columns that will be selected in the result request.
    esqResult.AddColumn("Id");
    esqResult.AddColumn("Name");
    // Receiving the Select instance associated with the created EntitySchemaQuery request.
    Select selectEsq = esqResult.GetSelectQuery(SystemUserConnection);
    // Receiving the text of the resulting request of the created EntitySchemaQuery instance.
    result = selectEsq.GetSqlText();
    return result;
}

public string CreateESQClone()
{
    var result = "";
    EntitySchemaManager esqManager = SystemUserConnection.EntitySchemaManager;
    var esqSource = new EntitySchemaQuery(esqManager, "Contact");
    esqSource.AddColumn("Id");
    esqSource.AddColumn("Name");
    // Creating an EntitySchemaQuery instance that is a clone of the esqSource instance.
    var esqClone = new EntitySchemaQuery(esqSource);
    result = esqClone.GetSelectQuery(SystemUserConnection).GetSqlText();
    return result;
}

public string GetEntitiesExample()
{
    var result = "";
    // Creating a request to the City schema, adding the Name column to the request.
    var esqResult = new EntitySchemaQuery(UserConnection.EntitySchemaManager, "City");
    var colName = esqResult.AddColumn("Name");

    // Running the request to the database and receiving the resulting object collection.
    var entities = esqResult.GetEntityCollection(UserConnection);
    for (int i=0; i < entities.Length; i++) {
        result += entities[i].GetColumnValue(colName.Name).ToString();
        result += "\n";
    }
    
    // Running the request to the database and receiving an object with the specified identifier.
    var entity = esqResult.GetEntity(UserConnection, new Guid("100B6B13-E8BB-DF11-B00F-001D60E938C6"));
    result += "\n";
    result += entity.GetColumnValue(colName.Name).ToString();
    return result;
}

public Collection<string> UsingCacheExample()
{
    // Creating a request to the City schema, adding the Name column to the request.
    var esqResult = new EntitySchemaQuery(UserConnection.EntitySchemaManager, "City");
    esqResult.AddColumn("Name");

    // Identifying the key that will be used to store the request results in the cache.
    // Creatio cache of the local data cache session level acts as a cache (since the
    // Cache property of the object cannot be identified).
    esqResult.CacheItemName = "EsqResultItem";

    // Collection that will contain the request results.
    var esqCityNames = new Collection<string>();

    // Collection that will contain the cached request results.
    var cachedEsqCityNames = new Collection<string>();

    // Running the requst to the database and receiving the resulting object collection.
    // After running the operation the results will be cached.
    var entities = esqResult.GetEntityCollection(UserConnection);

    // Processing the request results and populating the esqCityNames collection.
    foreach (var entity in entities)
    {
        esqCityNames.Add(entity.GetTypedColumnValue<string>("Name"));
    }

    // Receiving a link to the cache of the esqResult request using the CacheItemName key as a data table in memory.
    var esqCacheStore = esqResult.Cache[esqResult.CacheItemName] as DataTable;

    // Populating the cachedEsqCityNames collection with the values of the request cache.
    if (esqCacheStore != null)
    {
        foreach (DataRow row in esqCacheStore.Rows)
        {
            cachedEsqCityNames.Add(row[0].ToString());
        }
    }
    return cachedEsqCityNames;
}

public Collection<string> ESQOptionsExample()
{
    // Creating a request instance with the City root schema.
    var esqCities = new EntitySchemaQuery(UserConnection.EntitySchemaManager, "City");
    esqCities.AddColumn("Name");

    // Creating a request with the Country root schema.
    var esqCountries = new EntitySchemaQuery(UserConnection.EntitySchemaManager, "Country");
    esqCountries.AddColumn("Name");

    // Creating an instance of settings to return the first 5 strings by the request.
    var esqOptions = new EntitySchemaQueryOptions()
    {
        PageableDirection = PageableSelectDirection.First,
        PageableRowCount = 5,
        PageableConditionValues = new Dictionary<string, object>()
    };

    // Receiving a city collection that will contain the first 5 cities of the resulting data set.
    var cities = esqCities.GetEntityCollection(UserConnection, esqOptions);

    // Receiving a country collection that will contain the first 5 countries of the resulting data set.
    var countries = esqCountries.GetEntityCollection(UserConnection, esqOptions);
        var esqStringCollection = new Collection<string>();
    foreach (var entity in cities)
    {
        esqStringCollection.Add(entity.GetTypedColumnValue<string>("Name"));
    }
    foreach (var entity in countries)
    {
        esqStringCollection.Add(entity.GetTypedColumnValue<string>("Name"));
    }
    return esqStringCollection;
}