namespace WcfServiceLibrary
{
    [ServiceContract]
    public interface IDBAdapter
    {
        [OperationContract]
        DataTable GetTable();
    }    
}

namespace WcfServiceLibrary
{
    public class DBAdapter : IDBAdapter
    {
        #region IDBAdapter Members
        private string connStr = "Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=TestBase;Data Source=OXYGEN\\SQLEXPRESS";
        private SqlConnection connection;

        public DataTable GetTable()
        {
            DataTable result = new DataTable();
            connection = new SqlConnection(connStr);
            SqlDataAdapter daTest = new SqlDataAdapter("SELECT * FROM [testtable]", connection);
            daTest.Fill(result);
            return result;
        }

        #endregion        
    }
}

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <system.serviceModel>
    <services>
      <service behaviorConfiguration="MyServiceTypeBehaviors" name="WcfServiceLibrary.DBAdapter">
        <endpoint binding="wsHttpBinding" contract="WcfServiceLibrary.IDBAdapter" />
        <endpoint address="ep1" binding="wsHttpBinding" contract="IMetadataExchange" />
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8088/DBAdapter" />
          </baseAddresses>
        </host>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="MyServiceTypeBehaviors" >
          <serviceMetadata httpGetEnabled="true" />
        </behavior>
      </serviceBehaviors>
    </behaviors>

  </system.serviceModel>

</configuration>

namespace DBAdapterClient
{
    //------------------------------------------------------------------------------
    // <auto-generated>
    //     This code was generated by a tool.
    //     Runtime Version:2.0.50727.3053
    //
    //     Changes to this file may cause incorrect behavior and will be lost if
    //     the code is regenerated.
    // </auto-generated>
    //------------------------------------------------------------------------------    



    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]
    [System.ServiceModel.ServiceContractAttribute(ConfigurationName = "IDBAdapter")]
    public interface IDBAdapter
    {

        // CODEGEN: Parameter 'GetTableResult' requires additional schema information that cannot be captured using the parameter mode. The specific attribute is 'System.Xml.Serialization.XmlElementAttribute'.
        [System.ServiceModel.OperationContractAttribute(Action = "http://tempuri.org/IDBAdapter/GetTable", ReplyAction = "http://tempuri.org/IDBAdapter/GetTableResponse")]
        [System.ServiceModel.XmlSerializerFormatAttribute()]
        GetTableResponse GetTable(GetTableRequest request);
    }

    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]
    [System.ServiceModel.MessageContractAttribute(WrapperName = "GetTable", WrapperNamespace = "http://tempuri.org/", IsWrapped = true)]
    public partial class GetTableRequest
    {

        public GetTableRequest()
        {
        }
    }

    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]
    [System.ServiceModel.MessageContractAttribute(WrapperName = "GetTableResponse", WrapperNamespace = "http://tempuri.org/", IsWrapped = true)]
    public partial class GetTableResponse
    {

        [System.ServiceModel.MessageBodyMemberAttribute(Namespace = "http://tempuri.org/", Order = 0)]
        [System.Xml.Serialization.XmlElementAttribute(IsNullable = true)]
        public System.Data.DataTable GetTableResult;

        public GetTableResponse()
        {
        }

        public GetTableResponse(System.Data.DataTable GetTableResult)
        {
            this.GetTableResult = GetTableResult;
        }
    }

    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]
    public interface IDBAdapterChannel : IDBAdapter, System.ServiceModel.IClientChannel
    {
    }

    [System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]
    public partial class DBAdapterClient : System.ServiceModel.ClientBase<IDBAdapter>, IDBAdapter
    {

        public DBAdapterClient()
        {
        }

        public DBAdapterClient(string endpointConfigurationName) :
            base(endpointConfigurationName)
        {
        }

        public DBAdapterClient(string endpointConfigurationName, string remoteAddress) :
            base(endpointConfigurationName, remoteAddress)
        {
        }

        public DBAdapterClient(string endpointConfigurationName, System.ServiceModel.EndpointAddress remoteAddress) :
            base(endpointConfigurationName, remoteAddress)
        {
        }

        public DBAdapterClient(System.ServiceModel.Channels.Binding binding, System.ServiceModel.EndpointAddress remoteAddress) :
            base(binding, remoteAddress)
        {
        }

        [System.ComponentModel.EditorBrowsableAttribute(System.ComponentModel.EditorBrowsableState.Advanced)]
        GetTableResponse IDBAdapter.GetTable(GetTableRequest request)
        {
            return base.Channel.GetTable(request);
        }

        public System.Data.DataTable GetTable()
        {
            GetTableRequest inValue = new GetTableRequest();
            GetTableResponse retVal = ((IDBAdapter)(this)).GetTable(inValue);
            return retVal.GetTableResult;
        }
    }

}

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.serviceModel>
    <bindings>
      <wsHttpBinding>
        <binding name="wsHttpBinding_IDBAdapter" closeTimeout="00:01:00"
            openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
            bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"
            maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
            messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true"
            allowCookies="false">
          <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
              maxBytesPerRead="4096" maxNameTableCharCount="16384" />
          <reliableSession ordered="true" inactivityTimeout="00:10:00"
              enabled="false" />
          <security mode="Message">
            <transport clientCredentialType="Windows" proxyCredentialType="None"
                realm="" />
            <message clientCredentialType="Windows" negotiateServiceCredential="true"
                algorithmSuite="Default" establishSecurityContext="true" />
          </security>
        </binding>
      </wsHttpBinding>
    </bindings>
    <client>
      <endpoint address="http://localhost:8088/DBAdapter" binding="wsHttpBinding"
          bindingConfiguration="wsHttpBinding_IDBAdapter" contract="IDBAdapter"
          name="wsHttpBinding_IDBAdapter">
        <identity>
          <userPrincipalName value="OXYGEN\Zeran" />
        </identity>
      </endpoint>
    </client>
  </system.serviceModel>
</configuration>

namespace DBAdapterClient
{
    public partial class fMain : Form
    {
        //
        private DBAdapterClient dba = null;
        //
        public fMain()
        {
            InitializeComponent();
        }
        private void btnConnect_Click(object sender, EventArgs e)
        {
            dba = new DBAdapterClient();          
            gridTest.DataSource = dba.GetTable();
        }
    }
}

An error occurred while receiving the HTTP response to http://localhost:8088/DBAdapter. 
This could be due to the service endpoint binding not using the HTTP protocol. 
This could also be due to an HTTP request context being aborted by the server 
(possibly due to the service shutting down). See server logs for more details.