SQL Server

Compress a String to Gzip and Return as Base64

See more Gzip Examples

This example demonstrates how to use the CompressStringENC method to compress a string into Gzip format and return the result as an encoded string.

The input string is first converted to its byte representation using the specified character set (in this case, UTF-8). The bytes are then compressed using the Gzip format. Finally, the compressed binary data is encoded as a Base64 string.

Returning the compressed data as an encoded string is useful for safely transmitting or storing the data in text-based systems such as JSON, XML, or HTTP headers.

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
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This example demonstrates how to compress a string into Gzip format
    -- and return the compressed result as a Base64-encoded string.

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

    -- The string to be compressed:
    DECLARE @inputStr nvarchar(4000)
    SELECT @inputStr = 'The quick brown fox jumps over the lazy dog.'

    -- Compress the string using UTF-8, and return the result as Base64:
    DECLARE @compressedBase64 nvarchar(4000)
    EXEC sp_OAMethod @gzip, 'CompressStringENC', @compressedBase64 OUT, @inputStr, 'utf-8', 'base64'
    EXEC sp_OAGetProperty @gzip, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 = 0
      BEGIN
        EXEC sp_OAGetProperty @gzip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gzip
        RETURN
      END


    PRINT 'Original string: ' + @inputStr

    PRINT 'Compressed (Base64): ' + @compressedBase64

    -- Note: For very small strings, the compressed output may actually be larger
    -- than the original. This is because the Gzip format adds overhead such as
    -- headers and metadata. As the size of the input string increases, the
    -- compression becomes more effective and results in a smaller output.

    EXEC @hr = sp_OADestroy @gzip


END
GO