TBlob Record

Represents a binary large object (blob) that can be mapped to a database blob column by TMS Aurelius.

Remarks

Use TBlob as the type of a field or property in an entity class to map it to a blob column in the database. Compared to using a plain TArray<byte>, TBlob adds support for lazy-loading and provides convenience accessors for reading and writing the binary content as strings or byte arrays.

When the column is declared with TColumnProp.Lazy, Aurelius does not fetch the blob data together with the rest of the entity. The content is retrieved from the database on demand, the first time any data accessor (AsBytes, AsString, AsUnicodeString, Size, etc.) is used.

TBlob implicitly converts to and from TBytes, so it can be passed directly to methods that accept a byte array.

Syntax

Unit: Aurelius.Types.Blob

TBlob = record;

Constructors

Name	Description
Create	Creates a TBlob and initialises it with the provided byte array.

Methods

Name	Description
Clear	Clears the blob content, setting it to an empty (null) state.
LoadFromStream	Loads the blob content from a stream, replacing any existing data.
SaveToStream	Writes the blob content to a stream.

Operators

Name	Description
Implicit Conversion	Overloaded Implicit conversion from TBlob to TBytes Implicit conversion from TBytes to TBlob

Properties

Name	Description
AsBytes	Gets or sets the blob content as a TBytes byte array.
AsString	Gets or sets the blob content as an ANSI-encoded string.
AsUnicodeString	Gets or sets the blob content as a Unicode string.
Available	Indicates whether the blob content is available in memory without requiring a database request.
IsNull	Gets or sets whether the blob is empty (contains no data).
Loaded	Indicates whether the blob content has already been loaded from the database.
Size	Returns the size of the blob content in bytes.