Native Microsoft SQL Server client for iOS





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4yrs ago











Native Microsoft SQL Server client for iOS. An Objective-C wrapper around the open-source FreeTDS library.

Sample Usage

#import "SQLClient.h"

SQLClient* client = [SQLClient sharedInstance];
[client connect:@"server\instance:port" username:@"user" password:@"pass" database:@"db" completion:^(BOOL success) {
    if (success) {
      [client execute:@"SELECT * FROM Users" completion:^(NSArray* results) {
        for (NSArray* table in results) {
          for (NSDictionary* row in table) {
            for (NSString* column in row) {
              NSLog(@"%@=%@", column, row[column]);
        [client disconnect];


FreeTDS communicates both errors and messages. SQLClient rebroadcasts both via NSNotificationCenter:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(error:) name:SQLClientErrorNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(message:) name:SQLClientMessageNotification object:nil];  

- (void)error:(NSNotification*)notification
    NSNumber* code = notification.userInfo[SQLClientCodeKey];
    NSString* message = notification.userInfo[SQLClientMessageKey];
    NSNumber* severity = notification.userInfo[SQLClientSeverityKey];
    NSLog(@"Error #%@: %@ (Severity %@)", code, message, severity);

- (void)message:(NSNotification*)notification
    NSString* message = notification.userInfo[SQLClientMessageKey];
    NSLog(@"Message: %@", message);

Type Conversion

SQLClient maps SQL Server data types into the following native Objective-C types:

  • bigint → NSNumber
  • binary(n) → NSData
  • bit → NSNumber
  • char(n) → NSString
  • cursor → not supported
  • date → NSDate or NSString
  • datetime → NSDate
  • datetime2 → NSDate or NSString
  • datetimeoffset → NSDate or NSString
  • decimal(p,s) → NSNumber
  • float(n) → NSNumber
  • image → NSData
  • int → NSNumber
  • money → NSDecimalNumber (last 2 digits are truncated)
  • nchar → NSString
  • ntext → NSString
  • null → NSNull
  • numeric(p,s) → NSNumber
  • nvarchar → NSString
  • nvarchar(max) → NSString
  • real → NSNumber
  • smalldatetime → NSDate
  • smallint → NSNumber
  • smallmoney → NSDecimalNumber
  • sql_variant → not supported
  • table → not supported
  • text → NSString*
  • time → NSDate or NSString
  • timestamp → NSData
  • tinyint → NSNumber
  • uniqueidentifier → NSUUID
  • varbinary → NSData
  • varbinary(max) → NSData
  • varchar(max) → NSString*
  • varchar(n) → NSString
  • xml → NSString

*The maximum length of a string in a query is configured on the server via the SET TEXTSIZE command. To find out your current setting, execute SELECT @@TEXTSIZE. SQLClient uses 4096 by default. To override this setting, update the maxTextSize property.

†The following data types are only converted to NSDate on TDS version 7.3 and higher. By default FreeTDS uses version 7.1 of the TDS protocol, which converts them to NSString. To use a higher version of the TDS protocol, add an environment variable to Xcode named TDSVER. Possible values are 4.2, 5.0, 7.0, 7.1, 7.2, 7.3, 7.4, auto. A value of auto tells FreeTDS to use an autodetection (trial-and-error) algorithm to choose the highest available protocol version.

  • date
  • datetime2
  • datetimeoffset
  • time


The SQLClientTests target contains integration tests which require a connection to an instance of SQL Server. The integration tests have passed successfully on the following database servers:

  • SQL Server 7.0 (TDS 7.0)
  • SQL Server 2000 (TDS 7.1)
  • SQL Server 2005 (TDS 7.2)
  • SQL Server 2008 (TDS 7.3)
  • TODO: add more!

To configure the connection for your server:

  • In Xcode, go to Edit Scheme... and select the Test scheme.
  • On the Arguments tab, uncheck Use the Run action's arguments and environment variables
  • Add the following environment variables for your server. The values should be the same as you pass in to the connect: method.
    • HOST (server\instance:port)
    • DATABASE (optional)

Known Issues

PR's welcome!

  • strings: FreeTDS incorrectly returns an empty string "" for a single space " "
  • money: FreeTDS will truncate the rightmost 2 digits.
  • OSX support: FreeTDS-iOS needs to be compiled to support OSX and Podspec updated
  • No support for stored procedures with out parameters (yet)
  • No support for returning number of rows changed (yet)
  • Swift bindings: I welcome a PR to make the API more Swift-friendly

##Demo Project Open the Xcode project inside the SQLClient folder.



CocoaPods is the preferred way to install this library.

  1. Open a Terminal window. Update RubyGems by entering: sudo gem update --system. Enter your password when prompted.
  2. Install CocoaPods by entering sudo gem install cocoapods.
  3. Create a file at the root of your Xcode project folder called Podfile.
  4. Enter the following text: pod 'SQLClient', '~> 1.0.0'
  5. In Terminal navigate to this folder and enter pod install.
  6. You will see a new SQLClient.xcworkspace file. Open this file in Xcode to work with this project from now on.


  1. Drag and drop the contents of the SQLClient/SQLClient/SQLClient folder into your Xcode project.
  2. Select Copy items into destination group's folder (if needed).
  3. Go to Project > Build Phases > Link Binary With Libraries.
  4. Click + and add libiconv.dylib.


SQLClient Class Reference

SQLClient: A Native Microsoft SQL Server Library for iOS


FreeTDS: http://www.freetds.org

FreeTDS-iOS: https://github.com/patchhf/FreeTDS-iOS

FreeTDS example code in C: http://freetds.schemamania.org/userguide/samplecode.htm

SQL Server Logo © Microsoft

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