Module types

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TDS types: reading COLMETADATA and rows into Value, and encoding bound parameters on the way out.

SQL Server sends everything in binary, so unlike the PostgreSQL driver — which asks for text and parses it — this module owns a decoder per type. Two decisions are worth stating up front, because they look like omissions:

decimal, numeric and money come back as Value::Text. A decimal is an exact type; turning it into f64 would quietly lose the precision the column exists to preserve, and the framework has no decimal type yet.
date, time, datetime, datetime2 and datetimeoffset come back as text too, in ISO 8601 order. The framework has no date type yet, and the PostgreSQL driver already keeps timestamps as text, so a model that reads a timestamp as String behaves the same on both databases.

sql_variant is the one type this module cannot promise: it is decoded when its base type is one of the common scalars and returned as NULL otherwise, having consumed exactly the right number of bytes so the token stream stays aligned.

Structs§

Collation: The five collation bytes that follow every character type.
Column: One column of a result set.
TypeInfo: A column’s declared type, as COLMETADATA describes it.

Enums§

LengthStyle: How the value that follows a TYPE_INFO announces its own length.

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Functions§

as_json: A JSON document read back out of an nvarchar(max) column.
declare: The @params argument of sp_executesql: @P1 bigint, @P2 nvarchar(max).
encode: Encode one bound parameter as TYPE_INFO followed by its value.
parse_column_metadata: Read a COLMETADATA token body.
parse_type_info: Read a TYPE_INFO: the type byte and whatever describes its size.
read_nbc_row: Read one NBCROW token — a “null bitmap compressed” row.
read_row: Read one ROW token: every column, in order.
read_value: Read one value, given the type its column was declared with.

Module types

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Structs§

Enums§

Constants§

Functions§

Module types