Stream SQL Server Reference Documentation
Stream
Current Version: 11.6.0
Chilkat.Stream
Stream from a source file, byte array, string, or selected file part
without manually loading or copying all data first.
Write streamed data to a sink file, append to an existing file, or output
to
Read or write raw bytes, fixed byte counts, encoded byte strings,
individual bytes, or
Read and write strings using
Control read and write wait behavior, poll for immediately available
data, and inspect read or write failure reasons.
Track bytes sent and received, detect end-of-stream or write-closed
state, reset streams, close writing, and abort long-running operations.
Read, write, pipe, monitor, and control byte or text streams.
Chilkat.Stream is a general-purpose streaming object for moving
data between sources and sinks without requiring the entire payload to be
handled at once. A stream can read from files, byte arrays, strings, or other
sources; write to files, memory, BinData,
StringBuilder, or other sinks; handle binary and text data;
apply character-set rules for strings; process file parts; track bytes sent
and received; and support timeouts, polling, aborts, async task integration,
and end-of-stream handling.
File and memory sources
File and object sinks
BinData, StringBuilder, bytes, or strings.
Binary reads and writes
BinData content.
Text streaming
StringCharset, optionally use a
BOM, and read text until CRLF or a matching delimiter.
Timeouts and polling
Progress and lifecycle
BinData, or
StringBuilder. Check EndOfStream,
ReadFailReason, WriteFailReason,
NumReceived, NumSent, and
LastErrorText to understand stream progress and failures.
ReadTimeoutMs, a value of 0 means a polling
read, not an infinite timeout. For WriteTimeoutMs,
0 means return immediately if the stream cannot be written to
right away.
Object Creation
DECLARE @hr int
DECLARE @stream int
EXEC @hr = sp_OACreate 'Chilkat.Stream', @stream OUT
IF @hr <> 0
BEGIN
PRINT 'Failed to create ActiveX component'
RETURN
END
-- ... use @stream ...
EXEC @hr = sp_OADestroy @streamT-SQL uses the Chilkat ActiveX through the OLE Automation stored procedures. They must be enabled once on the server (EXEC sp_configure 'Ole Automation Procedures', 1; RECONFIGURE;), and the Chilkat ActiveX registered must match the bitness of the SQL Server instance (64-bit for a 64-bit SQL Server). To bind to a specific major version of Chilkat, append the major version number to the ProgID, such as sp_OACreate 'Chilkat.Stream.11' for Chilkat v11.*.*.
sp_OACreate returns an object token (an int) that is passed as the first argument of every sp_OAMethod, sp_OAGetProperty and sp_OASetProperty call, and released with sp_OADestroy. Objects returned by methods (such as an HttpResponse or JsonObject) are also tokens received through an int OUT parameter; they must likewise be destroyed, and the OUT parameter is NULL when the method fails to return an object. Objects passed as arguments are passed by their token. When an OLE Automation procedure itself fails (non-zero @hr), sp_OAGetErrorInfo describes the error.
Data types: strings are nvarchar(4000); integers, booleans (1 or 0) and object tokens are int; dates are datetime. In the signatures on this page, @success, @iResult, @sResult and the like are the OUT variables receiving a method's return value, @iValue / @sValue receive or supply a property value, and the remaining @ variables are the method's arguments in order.
A string returned through an OUT parameter is limited to 4000 characters. For longer values, retrieve the result as a result set into a table variable instead of an OUT parameter, for example DECLARE @tmp TABLE (outputLine ntext) followed by INSERT INTO @tmp EXEC sp_OAGetProperty @stream, 'LastErrorText'. See string length limitations for strings returned by sp_OAMethod calls.
Methods that pass or return raw byte arrays are not shown on this page, because varbinary(max) values cannot be exchanged through sp_OAMethod (see varbinary(max) limitation). Use the BinData-based alternatives (methods ending in Bd) or the base64 / hex string-encoded variants instead. Binary properties (such as LastBinaryResult) can be retrieved as a result set into a table variable, as shown in their signatures. Asynchronous (*Async) methods and event callbacks are not available from SQL Server.
Properties
AbortCurrent
EXEC sp_OASetProperty @stream, 'AbortCurrent', @iValue
When set to 1, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to 0 when the next method is called. When the abort occurs, this property is reset to 0. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)
CanRead
1 if the stream supports reading. Otherwise 0.
Note: A stream that supports reading, which has already reached the end-of-stream, will still have a CanRead value of 1. This property indicates the stream's inherent ability, and not whether or not the stream can be read at a particular moment in time.
CanWrite
1 if the stream supports writing. Otherwise 0.
Note: A stream that supports writing, which has already been closed for write, will still have a CanWrite value of 1. This property indicates the stream's inherent ability, and not whether or not the stream can be written at a particular moment in time.
DataAvailable
1 if it is known for sure that data is ready and waiting to be read. 0 if it is not known for sure (it may be that data is immediately available, but reading the stream with a ReadTimeoutMs of 0, which is to poll the stream, is the way to find out).
DebugLogFilePath
EXEC sp_OASetProperty @stream, 'DebugLogFilePath', @sValue
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
DefaultChunkSize
EXEC sp_OASetProperty @stream, 'DefaultChunkSize', @iValue
The default internal chunk size for reading or writing. The default value is 65536. If this property is set to 0, it will cause the default chunk size (65536) to be used. Note: The chunk size can have significant performance impact. If performance is an issue, be sure to experiment with different chunk sizes.
topEndOfStream
1 if the end-of-stream has already been reached. When the stream has already ended, all calls to Read* methods will return 0 with the ReadFailReason set to 3 (already at end-of-stream).
IsWriteClosed
1 if the stream is closed for writing. Once closed, no more data may be written to the stream.
LastBinaryResult
This property is mainly used in SQL Server stored procedures to retrieve binary data from the last method call that returned binary data. It is only accessible if Chilkat.Global.KeepBinaryResult is set to 1. This feature allows for the retrieval of large varbinary results in an SQL Server environment, which has restrictions on returning large data via method calls, though temp tables can handle binary properties.
LastErrorHtml
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastErrorText
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
LastErrorXml
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastMethodSuccess
EXEC sp_OASetProperty @stream, 'LastMethodSuccess', @iValue
Indicates the success or failure of the most recent method call: 1 means success, 0 means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
LastStringResult
In SQL Server stored procedures, this property holds the string return value of the most recent method call that returns a string. It is accessible only when Chilkat.Global.KeepStringResult is set to TRUE. SQL Server has limitations on string lengths returned from methods and properties, but temp tables can be used to access large strings.
LastStringResultLen
The length, in characters, of the string contained in the LastStringResult property.
topLength32
EXEC sp_OASetProperty @stream, 'Length32', @iValue
The length (in bytes) of the stream's source. If unknown, then this property will have a value of -1. This property may be set by the application if it knows in advance the length of the stream.
Setting this property also sets the Length property (which is a 64-bit integer).
topReadFailReason
This property is automatically set when a Read* method is called. It indicates the reason for failure. Possible values are:
- 0>
- No failure (success)
- Timeout, or no data is immediately available for a polling read.
- Aborted by an application callback.
- Already at end-of-stream.
- Fatal stream error.
- Out-of-memory error (this is very unlikely).
ReadTimeoutMs
EXEC sp_OASetProperty @stream, 'ReadTimeoutMs', @iValue
The maximum number of seconds to wait while reading. The default value is 30 seconds (i.e. 30000ms). A value of 0 indicates a poll. (A polling read is to return with a timeout if no data is immediately available.)
Important: For most Chilkat timeout related properties, a value of 0 indicates an infinite timeout. For this property, a value of 0 indicates a poll. If setting a timeout related property (or method argument) to zero, be sure to understand if 0 means wait forever or poll.
The timeout value is not a total timeout. It is the maximum time to wait while no additional data is forthcoming.
topSinkFile
EXEC sp_OASetProperty @stream, 'SinkFile', @sValue
Sets the sink to the path of a file. The file does not need to exist at the time of setting this property. The sink file will be automatically opened on demand, when the stream is first written.
Note: This property takes priority over other potential sinks. Make sure this property is set to an empty string if the stream's sink is to be something else.
topSinkFileAppend
EXEC sp_OASetProperty @stream, 'SinkFileAppend', @iValue
If 1, the stream appends to the SinkFile rather than truncating and re-writing the sink file. The default value is 0.
SourceFile
EXEC sp_OASetProperty @stream, 'SourceFile', @sValue
Sets the source to the path of a file. The file does not need to exist at the time of setting this property. The source file will be automatically opened on demand, when the stream is first read.
Note: This property takes priority over other potential sources. Make sure this property is set to an empty string if the stream's source is to be something else.
topSourceFilePart
EXEC sp_OASetProperty @stream, 'SourceFilePart', @iValue
If the source is a file, then this property can be used to stream one part of the file. The SourceFilePartSize property defines the size (in bytes) of each part. The SourceFilePart and SourceFilePartSize have default values of 0, which means the entire SourceFile is streamed.
This property is a 0-based index. For example, if the SourceFilePartSize is 1000, then part 0 is for bytes 0 to 999, part 1 is for bytes 1000 to 1999, etc.
SourceFilePartSize
EXEC sp_OASetProperty @stream, 'SourceFilePartSize', @iValue
If the source is a file, then this property, in conjunction with the SourceFilePart property, can be used to stream a single part of the file. This property defines the size (in bytes) of each part. The SourceFilePart and SourceFilePartSize have default values of 0, which means that by default, the entire SourceFile is streamed.
StringBom
EXEC sp_OASetProperty @stream, 'StringBom', @iValue
If 1, then include the BOM when creating a string source via SetSourceString where the charset is utf-8, utf-16, etc. (The term BOM stands for Byte Order Mark, also known as the preamble.) Also, if 1, then include the BOM when writing a string via the WriteString method. The default value of this property is 0.
StringCharset
EXEC sp_OASetProperty @stream, 'StringCharset', @sValue
Indicates the expected character encoding, such as utf-8, windows-1256, utf-16, etc. for methods that read text such as: ReadString, ReadToCRLF, ReadUntilMatch. Also controls the character encoding when writing strings with the WriteString method. The supported charsets are indicated at the link below.
The default value is utf-8.
VerboseLogging
EXEC sp_OASetProperty @stream, 'VerboseLogging', @iValue
If set to 1, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is 0. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.
Version
WriteFailReason
This property is automatically set when a Write* method is called. It indicates the reason for failure. Possible values are:
- 0>
- No failure (success)
- Timeout, or unable to immediately write when the WriteTimeoutMs is 0.
- Aborted by an application callback.
- The stream has already ended.
- Fatal stream error.
- Out-of-memory error (this is very unlikely).
WriteTimeoutMs
EXEC sp_OASetProperty @stream, 'WriteTimeoutMs', @iValue
The maximum number of seconds to wait while writing. The default value is 30 seconds (i.e. 30000ms). A value of 0 indicates to return immediately if it is not possible to write to the sink immediately.
topMethods
ReadBd
Read as much data as is immediately available on the stream. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The incoming data is appended to binData.
Returns 1 for success, 0 for failure.
topReadBytesENC
The same as ReadBytes, except returns the received bytes in encoded string form. The encoding argument indicates the encoding, which can be base64, hex, or any of the multitude of encodings indicated in the link below.
Returns NULL on failure
ReadNBytesENC
The same as ReadNBytes, except returns the received bytes in encoded string form. The encoding argument indicates the encoding, which can be base64, hex, or any of the multitude of encodings indicated in the link below.
Returns NULL on failure
ReadSb
Read as much data as is immediately available on the stream. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is appended to sb. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadSb.
Returns 1 for success, 0 for failure.
topReadString
Read as much data as is immediately available on the stream. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is returned as a string. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadString.
Returns NULL on failure
ReadToCRLF
Reads the stream until a CRLF is received. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is returned as a string. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadString.
Note: If the end-of-stream is reached prior to receiving the CRLF, then the remaining data is returned, and the ReadFailReason property will be set to 3 (to indicate end-of-file). This is the only case where as string would be returned that does not end with CRLF.
Returns NULL on failure
ReadUntilMatch
Reads the stream until the string indicated by matchStr is received. If no data is immediately available, it waits up to ReadTimeoutMs milliseconds for data to arrive. The data is returned as a string. The incoming bytes are interpreted according to the StringCharset property. For example, if utf-8 bytes are expected, then StringCharset should be set to utf-8 prior to calling ReadString.
Note: If the end-of-stream is reached prior to receiving the match string, then the remaining data is returned, and the ReadFailReason property will be set to 3 (to indicate end-of-file). This is the only case where as string would be returned that does not end with the desired match string.
Returns NULL on failure
Reset
Resets the stream. If a source or sink is open, then it is closed. Properties such as EndOfStream and IsWriteClose are reset to default values.
topSetSourceString
Sets the stream's source to the contents of srcStr. The charset indicates the character encoding to be used for the byte representation of the srcStr.
Returns 1 for success, 0 for failure.
topToDecimalStr
Some programming languages do not support 64-bit integers. The following properties are implemented as 64-bit ints: Length, NumReceived, NumSent. The value of these properties can be retrieved in decimal string form by passing the property name in propertyName.
Returns NULL on failure
WriteBd
WriteByte
Writes a single byte to the stream. The byteVal must have a value from 0 to 255.
Returns 1 for success, 0 for failure.
topWriteBytesENC
Writes binary bytes to a stream. The byte data is passed in encoded string form, where the encoding can be base64, hex, or any of the supported binary encodings listed at the link below.
Returns 1 for success, 0 for failure.
WriteClose
WriteSb
Writes the contents of sb to the stream. The actual bytes written are the byte representation of the string as indicated by the StringCharset property. For example, to write utf-8 bytes, first set StringCharset equal to utf-8 and then call WriteSb.
Returns 1 for success, 0 for failure.
topWriteString
Writes a string to a stream. The actual bytes written are the byte representation of the string as indicated by the StringCharset property. For example, to write utf-8 bytes, first set StringCharset equal to utf-8 and then call WriteString.
Returns 1 for success, 0 for failure.
top