SQL Server

Compress Text from StringBuilder to Gzip (BinData Output)

See more Gzip Examples

This example demonstrates how to use the CompressSb method to compress text stored in a StringBuilder into Gzip format.

The text is first converted to its byte representation using the specified character set (in this case, UTF-8). These bytes are then compressed, and the resulting Gzip data is written to a BinData object in memory.

This approach is useful when working with dynamically generated text that you want to compress without first writing it to a file. The example also shows how the compressed data can optionally be saved to a .gz file.

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)
    DECLARE @success int
    SELECT @success = 0

    -- This example demonstrates how to compress text contained in a StringBuilder
    -- into Gzip format, storing the compressed result in a BinData object.

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

    DECLARE @sb int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sb OUT

    DECLARE @bd int
    EXEC @hr = sp_OACreate 'Chilkat.BinData', @bd OUT

    -- Add some text to the StringBuilder:
    EXEC sp_OAMethod @sb, 'Append', @success OUT, 'The quick brown fox jumps over the lazy dog.'

    -- Compress the text using UTF-8 encoding:
    EXEC sp_OAMethod @gzip, 'CompressSb', @success OUT, @sb, 'utf-8', @bd
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @gzip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gzip
        EXEC @hr = sp_OADestroy @sb
        EXEC @hr = sp_OADestroy @bd
        RETURN
      END

    -- The BinData now contains the Gzip-compressed bytes.

    PRINT 'Compression successful.'

    EXEC sp_OAGetProperty @bd, 'NumBytes', @iTmp0 OUT
    PRINT 'Compressed size (bytes): ' + @iTmp0

    -- (Optional) Save to a .gz file:
    EXEC sp_OAMethod @bd, 'WriteFile', @success OUT, 'text.gz'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @bd, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @gzip
        EXEC @hr = sp_OADestroy @sb
        EXEC @hr = sp_OADestroy @bd
        RETURN
      END


    PRINT 'Gzip file written to text.gz'

    EXEC @hr = sp_OADestroy @gzip
    EXEC @hr = sp_OADestroy @sb
    EXEC @hr = sp_OADestroy @bd


END
GO