Changes for version 0.900004 - 2026-11-08
- Storage
- A schema that declares DBIO::MSSQL::Storage gets, on first use, the class for the DBD of its DSN (DBD::ODBC or DBD::Sybase, including the FreeTDS class), without a "Driver mismatch" warning and without asking the server. A private subclass pinned over DBD::Sybase, or an ODBC class pinned over a dbi:Sybase: DSN, is refused with a message that names the class to derive from (ADR 0008).
- Connection parameters without a DSN ({dbname, host, port}) give a DBD::Sybase DSN; host and port come as a pair. A host bound by a Replicated view goes into a DBD::ODBC DSN as Server=host[,port].
- supports_exists_query and transactional_ddl are declared: results_exist works, and a deploy runs in one transaction.
- explain drives SET SHOWPLAN_ALL around the query over DBD::Sybase and is refused over DBD::ODBC, which returns no plan.
- except_all and intersect_all are refused, SQL Server has neither.
- Binary columns carry their bytes over both access paths. Over DBD::Sybase they are read back as bytes, and a bind value of more than 4000 bytes arrives whole.
- Over DBD::Sybase a bound string beyond ASCII, a value over the session's TEXTSIZE (LongReadLen) and a SQL_VARIANT result are refused instead of stored padded or cut, and a bound empty string is stored as ''. The POD of DBIO::MSSQL::Storage::Sybase carries the support matrix of DBD::ODBC against DBD::Sybase.
- Over DBD::Sybase and FreeTDS the key of a new row is read with SCOPE_IDENTITY(), populate on the NoBindVars class inserts row by row, and populate stops at the first tuple the server refuses.
- A transaction with an open cursor over DBD::Sybase and FreeTDS stays on its connection (DBIO::Sybase::Storage::FreeTDS).
- The text SQL Server writes into an error carries no values: the value of a failed conversion or overflow, the key values of a duplicate key, the start of a truncated value and the token of a syntax error are replaced by ***, bound values of four characters or more everywhere in the text. Table, column and constraint names, the error position and "with N bind values" stay (DBIO::MSSQL::Util::mask_error_details, ADR 0009).
- Placeholders are found with split_at_placeholders, so a ? in a literal or a quoted name is text; error texts carry neither password, DSN nor bind values.
- ODBC
- Text beyond the database code page arrives in NCHAR, NVARCHAR and NTEXT columns (CJK, emoji); a client character set that is not UTF-8 is refused. A text column is read back as characters.
- LongReadLen defaults to 1 GiB, so LOB columns are not cut at 80 bytes; the POD names the memory price.
- DDL
- install_ddl writes FOREIGN KEY constraints from belongs_to as named ALTER TABLE statements after all tables, named unique constraints (UQ_<table>_<columns>) and PK_<table>. No second index is written over the columns of a key.
- Indexes follow the canonical declaration (idx, indices) with an mssql block for the kind, and CREATE [UNIQUE] [CLUSTERED | NONCLUSTERED] INDEX is spelled as the server expects. Filtered indexes (a where key) are introspected, written and diffed.
- schema.table is made in its schema, with CREATE SCHEMA; schemas => [...] reads further schemas.
- One function quotes every name (reserved words, [ ] brackets), string defaults are literals, and foreign key columns follow the order of the key they reference.
- Decimal precision and scale, character lengths and (max) are kept; a column without is_nullable deploys as NOT NULL.
- What SQL Server cannot hold is refused with an exception naming table and column: enum, a sized bit, dotted names, cascade paths (Msg 1785), name clashes, a second clustered index, bad type parameters and string defaults on numeric or date types.
- Diff
- Statements are ordered for the server: foreign key drops first, new tables without inline keys, foreign key adds last, so referencing tables in any order upgrade.
- Primary keys are added, replaced and dropped on existing tables, CLUSTERED or NONCLUSTERED included; foreign keys, indexes and unique constraints around a changing key or column are dropped and created again. Unique constraints are constraints, not indexes.
- ALTER COLUMN is one statement with type and nullability, and a removed default drops its DEFAULT constraint.
- Views are created, replaced and dropped in dependency order; cycles are refused before the first statement. Index kind is compared.
- Names follow the collation of the live database, and a missing schema is created.
- Deploy
- apply and upgrade are the base class's: allow_destructive and dry_run hold here, lossy column type changes need allow_destructive, and a NOT NULL column without default over rows or NOT NULL over a NULL is refused before the first statement.
- The temporary database takes the collation of the live one and its connection from the connect info; a handle with AutoCommit off is refused, and DBIO::MSSQL::Storage::Sybase deploys with DBIO::MSSQL::Deploy.
- Introspect
- Every catalog column is aliased in lower case, independent of the handle's FetchHashKeyName. Columns carry the DEFAULT constraint name and the primary key's name and kind; views carry their definition.
- SQLMaker
- order_by with -nulls => 'first' | 'last' is emulated with a CASE sort key, also in the ROW_NUMBER limit.
- Test Modules
- DBIO::MSSQL::Test::Conformance answers the shared DDL, Diff and Bind case tables of core, live against a server with a database per case.
- Documentation
- README states the async stance of this sync-only driver and the Perl 5.20 floor; the POD describes limit dialect, ordered subselects and MONEY as the code has them.
- ADR 0007 records the storage shape (a transport-neutral base plus one class per DBD); ADR 0036 proposes a MERGE-based upsert, and $rs->upsert throws on SQL Server until it lands.
- Packaging
- Requires DBIO 0.900004. The cpanfile names the modules Storage loads (Context::Preserve, Scope::Guard, Try::Tiny), and DBD::ODBC is recommended.
- Every module carries $VERSION in step with the distribution.
Documentation
Modules
Microsoft SQL Server-specific schema management for DBIO
MSSQL base->native type resolver
Generate MSSQL DDL from DBIO Result classes
Deploy and upgrade MSSQL schemas via test-deploy-and-compare
Compare two introspected MSSQL models
Diff operations for MSSQL columns
Diff operations for MSSQL foreign keys
Diff operations for MSSQL indexes
Diff operations for MSSQL primary keys
Diff operations for MSSQL schemas
Diff operations for MSSQL tables
Diff operations for MSSQL views
Introspect a Microsoft SQL Server database via information_schema
Introspect MSSQL columns
Introspect MSSQL foreign keys
Introspect MSSQL indexes
Introspect MSSQL tables and views
Introspect MSSQL view definitions
MSSQL-specific Result component for DBIO
MSSQL-specific SQL generation for DBIO
Base Class for Microsoft SQL Server support in DBIO
DateTime parser for MSSQL datetime and smalldatetime columns
Support for Microsoft SQL Server via DBD::ODBC
A statement handle whose execute_for_fetch stops at the first failing tuple
Support for Microsoft SQL Server via DBD::Sybase
DateTime parser for MSSQL via DBD::Sybase
Support for Microsoft SQL Server via DBD::Sybase without placeholders
Answers the shared conformance case table for the SQL Server driver
Shared MSSQL-specific helper functions for DBIO
`use DBIO -ms` shortcut for the MSSQL driver