SQL Server

GZip Create / Extract .gz File

See more Gzip Examples

Demonstrates how to compress a file to create a .gz (GZip) file.

Note: The .gz file format is a compressed file format. It contains a single file. The .gz file format is not an archive format (i.e. it does not contain a collection of files/directories such as with the .zip, .rar, or .tar file formats). GZip is often combined with TAR to create a .tgz (or .tar.gz).

Note: It is possible for a .gz to contain more than one file, but this is very uncommon.

SQL Server

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @gzip int
    EXEC @hr = sp_OACreate 'Chilkat.Gzip', @gzip OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    -- File-to-file GZip:
    -- Compress "hamlet.xml" to create "hamlet.xml.gz"
    EXEC sp_OAMethod @gzip, 'CompressFile', @success OUT, 'hamlet.xml', 'hamlet.xml.gz'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @gzip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gzip
        RETURN
      END

    -- File-to-file ungzip
    -- Decompress "hamlet.xml.gz" to create "hamletOut.xml"
    EXEC sp_OAMethod @gzip, 'UncompressFile', @success OUT, 'hamlet.xml.gz', 'hamletOut.xml'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @gzip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gzip
        RETURN
      END

    -- File-to-string ungzip
    -- Decompress the contents of a .gz directly to a string variable:
    -- The 2nd argument indicates the charset of the character
    -- data after it is decompressed.
    DECLARE @xmlStr nvarchar(4000)

    EXEC sp_OAMethod @gzip, 'UncompressFileToString', @xmlStr OUT, 'hamlet.xml.gz', 'utf-8'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @gzip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gzip
        RETURN
      END


    PRINT @xmlStr

    -- The Chilkat GZip API provides much more flexibility than shown
    -- here.  See the reference documentation at 
    -- http://www.chilkatsoft.com/refdoc for more information

    EXEC @hr = sp_OADestroy @gzip


END
GO