SQL Server

Unzip a Text File Entry into a StringBuilder Using ZipEntry.UnzipToSb

See more Zip Examples

This example demonstrates how to use the ZipEntry.UnzipToSb method to inflate a text file entry directly into a StringBuilder object.

The ZIP entry is uncompressed entirely in memory and appended to the StringBuilder without creating a temporary file on disk.

This is useful when:

• Processing text files directly in memory
• Avoiding temporary filesystem files
• Reading configuration files, JSON, XML, CSV, or source code from ZIP archives
• Automatically converting line endings while inflating the text

The srcCharset argument specifies how the uncompressed bytes should be interpreted, such as:

• utf-8
• utf-16
• windows-1252

The lineEndingBehavior argument controls line-ending conversion:

• 0 — Leave line endings unchanged
• 1 — Convert all line endings to bare LF
• 2 — Convert all line endings to CRLF

Suppose the ZIP archive contains:

config/settings.json

The example inflates the JSON file directly into a StringBuilder.

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

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

    -- Open an existing ZIP archive.
    EXEC sp_OAMethod @zip, 'OpenZip', @success OUT, 'qa_data/zips/configFiles.zip'
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @zip, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @zip
        RETURN
      END

    -- Locate the JSON file entry within the ZIP archive.
    DECLARE @entry int
    EXEC @hr = sp_OACreate 'Chilkat.ZipEntry', @entry OUT

    EXEC sp_OAMethod @zip, 'EntryOf', @success OUT, 'config/settings.json', @entry
    IF @success = 0
      BEGIN

        PRINT 'ZIP entry not found.'
        EXEC sp_OAMethod @zip, 'CloseZip', NULL
        EXEC @hr = sp_OADestroy @zip
        EXEC @hr = sp_OADestroy @entry
        RETURN
      END

    -- ------------------------------------------------------------
    -- Inflate the ZIP entry directly into a StringBuilder.
    -- 
    -- The uncompressed text is appended to the StringBuilder.
    -- 
    DECLARE @sb int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sb OUT

    -- Leave line endings unchanged.
    DECLARE @lineEndingBehavior int
    SELECT @lineEndingBehavior = 0

    -- Interpret the uncompressed bytes as UTF-8 text.
    DECLARE @srcCharset nvarchar(4000)
    SELECT @srcCharset = 'utf-8'

    EXEC sp_OAMethod @entry, 'UnzipToSb', @success OUT, @lineEndingBehavior, @srcCharset, @sb
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @entry, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @zip
        EXEC @hr = sp_OADestroy @entry
        EXEC @hr = sp_OADestroy @sb
        RETURN
      END


    PRINT 'Uncompressed text:'

    PRINT ''
    EXEC sp_OAMethod @sb, 'GetAsString', @sTmp0 OUT
    PRINT @sTmp0

    EXEC sp_OAMethod @zip, 'CloseZip', NULL


    PRINT 'Done.'

    EXEC @hr = sp_OADestroy @zip
    EXEC @hr = sp_OADestroy @entry
    EXEC @hr = sp_OADestroy @sb


END
GO