Chat message history backed by SQL Server / Azure SQL.
Provides :class:SQLServerChatMessageHistory, an implementation of
langchain_core.chat_history.BaseChatMessageHistory that persists messages
to a SQL Server table.
Chat message history stored in a SQL Server table.
Each instance is scoped to a single session_id; multiple sessions can
share the same underlying table.
The table is created on first use if it does not already exist. Messages
are stored serialized as JSON in an NVARCHAR(MAX) column and ordered
by an auto-incrementing id column on read, so insertion order is
preserved.
The class supports both username/password connections and Entra ID
authentication using the same connection-string conventions as
:class:langchain_sqlserver.SQLServer_VectorStore.
