Oracle
SQL Server

Oracle to SQL Server Converter

Move Oracle workloads into SQL Server, Azure SQL, or Amazon RDS for SQL Server. Schema conversion, type mapping, and optional two-way sync.

Oracle to SQL Server is usually a Microsoft-stack consolidation move - the buyer is already running SQL Server elsewhere, Active Directory, Power BI, or Azure, and Oracle is the odd database out.

Cost matters, but ecosystem alignment is usually what drives the decision. The data copy is the easy part; reshaping the schema for T-SQL and rebuilding stored logic is where the engineering cost lives.

What DBConvert does on this path: handles the Oracle → SQL Server extract as a repeatable desktop workflow:

  • Reads Oracle Database and Oracle Database XE via OCI / Instant Client.
  • Writes to SQL Server, SQL Server Express, Azure SQL Database, Azure SQL Managed Instance, or Amazon RDS for SQL Server.
  • Lets you review type mapping per table before creating SQL Server tables, rows, indexes, and supported view objects.
  • Saved sessions, CLI for scheduled runs, optional DBSync for staged cutover and reverse-direction refresh.

What it does not do: PL/SQL packages, procedures, functions, triggers, materialized views, and Oracle hints are not converted to T-SQL - server-side code stays on Oracle or has to be rewritten as T-SQL.

Which tool: DBConvert or DBSync?

DBConvert for Oracle → SQL Server

One-time conversion. Use it when SQL Server (or Azure SQL / Amazon RDS) is the destination and you need schema, table data, indexes, relationships, and view-query translation moved through a desktop wizard in a single cutover.

DBSync for Oracle ↔ SQL Server

Repeat synchronization. Use it when Oracle has to stay live while SQL Server takes over application traffic in stages, or when Insert / Update / Delete changes must keep flowing between the two during a phased migration.

Need more context? Compare DBConvert and DBSync side by side →

How DBConvert handles the Oracle → SQL Server differences

Oracle and SQL Server differ in numeric precision, sequence handling, NULL semantics, application-SQL constructs, and procedural code. DBConvert maps most of those differences in the wizard with sensible defaults that you can review or override per table; PL/SQL rewrite and application-SQL portability are the two items that still need a human.

Type mapping

Oracle type SQL Server default
NUMBERDECIMAL(38,10) (route to INT / BIGINT per column for PKs / FKs in the review)
VARCHAR2NVARCHAR
CLOBNVARCHAR(MAX)
DATEDATETIME2
TIMESTAMP WITH TIME ZONEDATETIMEOFFSET
BLOB / RAWVARBINARY(MAX)

ROWID / UROWID have no SQL Server equivalent - reported in the wizard so the schema decision (drop / replace with surrogate) is explicit.

Sequences and identity

Creates SQL Server SEQUENCE objects (2012+) for multi-table Oracle sequences, or collapses single-table sequences into IDENTITY columns, and sets the next value above the loaded maximum key value - application inserts do not collide.

NULL and empty-string semantics

Oracle treats an empty string as NULL; SQL Server treats it as a zero-length string. DBConvert preserves Oracle's NULL semantics on the target where columns are NULL in the source - application code that checks for empty input still needs a review pass before cutover.

Application SQL portability

Oracle-specific query syntax does not run unchanged against SQL Server: scalar functions (NVL → ISNULL, SYSDATE → GETDATE(), NVL2 → IIF) are one-for-one, but structural constructs need a rewrite (CONNECT BY → recursive CTE, MINUS → EXCEPT, ROWNUM → TOP / OFFSET FETCH, Oracle (+) outer joins → ANSI LEFT JOIN). DBConvert moves the schema and data; the application SQL layer is its own search-and-replace task.

Views translation - two-way

Translates view definitions and supported queries between Oracle and SQL Server in both directions during the migration - one of the three native two-way-translation pairs (MySQL ↔ SQL Server, MySQL ↔ Oracle, SQL Server ↔ Oracle).

Stored procedures, triggers, and procedural code - out of scope

DBConvert's migration covers tables (with their fields, types, defaults, and indexes), views, and foreign keys. PL/SQL packages, procedures, functions, triggers, materialized views, and Oracle optimizer hints stay in the source and are rewritten manually in T-SQL. Typically a small fraction of the schema, but the one item the tool does not handle.

Choosing the migration route

Use DBConvert when the project needs a desktop wizard, saved sessions, type-mapping review, and optional DBSync. Use the other routes when the project is specifically Microsoft-native assessment, SSIS ETL, AWS cutover infrastructure, or Oracle real-time replication.

Route Where it fits Where it falls short
SSMA for Oracle Microsoft Migration Assistant, free Microsoft's official path and the AI-recommended starting point. Assessment HTML report, schema conversion with per-table type-mapping review, data migration, and SSMA Tester validation. Targets SQL Server, Azure SQL Database, and Azure SQL Managed Instance. Recent versions include Copilot-assisted code translation for harder PL/SQL. Cannot migrate SYS / SYSTEM schemas; non-scalar WHERE conditions are not auto-converted (error O2SS0001); PL/SQL packages with state, autonomous transactions, and Oracle-only functions still need manual rewrite; one-time only with no built-in continuous sync.
SSIS with Oracle source Microsoft ETL Data-only pipelines when the migration is part of a larger SSIS package that runs other ETL anyway. Useful for bulk loads and custom data flows after SSMA has handled the schema. No schema or PL/SQL conversion; package setup and Oracle provider configuration are non-trivial; separate tool to maintain than the wizard that loaded it.
AWS SCT + AWS DMS cloud-AWS specific When the target is Amazon RDS for SQL Server and the rest of the stack lives in AWS. SCT handles schema assessment, DMS handles full-load plus change replication. Not the obvious first choice for Oracle → SQL Server (AWS DMS is stronger for Oracle → PostgreSQL). Coupled to AWS endpoints and billing; no desktop GUI for type-mapping review.
Oracle GoldenGate Oracle real-time replication Continuous heterogeneous replication for organisations that already license GoldenGate and need sub-second latency between Oracle and SQL Server during a long parallel-run phase. Enterprise pricing; operationally heavy; overkill for a one-time migration or a planned maintenance window.
DBConvert / DBSync commercial desktop, Windows Desktop wizard with saved sessions, per-table type-mapping review, Oracle view-query translation, scheduler, and CLI. Writes to SQL Server / Azure SQL / Azure SQL MI / Amazon RDS for SQL Server. DBSync handles staged cutover and reverse-direction refresh. Commercial license; desktop tool (Windows). PL/SQL packages, procedures, functions, triggers, and materialized views are still rewrite work.

Common confusion: Ora2Pg targets PostgreSQL, not SQL Server. If you landed here after searching for “Ora2Pg for SQL Server,” you want the Oracle to PostgreSQL page instead.

Supported versions

  • Oracle 10g and later, including Oracle XE and Oracle Cloud
  • No Oracle client or ODBC driver required
  • SQL Server 2008–2022, including Express editions
  • Azure SQL Database and Amazon RDS for SQL Server
  • SQL Server schemas (dbo, custom schemas)
  • Windows authentication or SQL authentication

Supported in this path

Source Oracle
Target SQL Server
Oracle Database Oracle Database XE Microsoft SQL Server SQL Server Express Azure SQL Database Azure SQL Managed Instance Amazon RDS for SQL Server
Oracle

All Oracle Tools

Other directions and pairs
SQL Server

All SQL Server Tools

Migration & sync options

Reverse Conversion

SQL Server to Oracle

Using Oracle to SQL Server Tools

When launching the DBConvert or DBSync application in GUI mode, it guides you through the steps to start database migration or synchronization:

1

Connect to Oracle source database

Specify the username/password and host/port parameters if your source database requires login credentials.

Connect to Oracle source database from DBConvert

Oracle source

Oracle connects through Instant Client / OCI. Use Oracle migration issues if client, NLS, or authentication errors appear.

2

Connect to SQL Server destination database

Specify parameters for the destination database similar to the source, defining connection settings and username/password pairs.

Connect to SQL Server target database from DBConvert

SQL Server target

Use SQL Server connection settings. Azure SQL needs SQL authentication, SSL, and outbound TCP 1433.

More guides for Oracle ↔ SQL Server

Next steps: configure, validate, run

After connecting source and target, the remaining steps are the same for every database pair:

  • Configure migration options - pick tables, fields, indices, views.
  • Issue detection - the built-in checker flags integrity problems before migration starts.
  • Execute - commit the job, monitor progress, save the session for reuse.
  • Schedule and CLI - rerun saved sessions on a schedule or from the command line.
Open the full guide

Steps 3-5, software features, command-line mode, scheduler, and system requirements.

See all features