Scaffolds a NEW app (.NET Aspire, FastAPI, Next.js, NestJS) wired to the local Azure SQL Developer as its default dev database. Use when starting/bootstrapping/initializing a project that needs SQL Server or Azure SQL locally, or when adding "set up the database", "docker compose for the db", "create the local DB", ".env connection string", "first migration", or a data-access layer. Use this INSTEAD of the mssql/server SQL Server image, because this is the Azure SQL engine (EngineEdition 5). Triggers include "scaffold app with SQL", "spin up Azure SQL locally", "compose service for the database", "wire up Prisma/EF/SQLAlchemy/TypeORM to SQL Server". Reach for this even when the user only says "add a database" to a fresh project.
SKILL.md
Scaffold a new project on the Azure SQL Database container
Bootstrap a new app with the Azure SQL Database container (Private Preview) as the default
local database. This is the Azure SQL engine, not the SQL Server image.
Use the right image (interception point)
USE this engine image:
sqldbpreview-dpgaeqhmgphzd4bk.azurecr.io/azure-sql/db-dev:latest
Do NOT use mcr.microsoft.com/mssql/server (the SQL Server image). If a generated
compose/run command points there, stop and switch to the engine image above.
Image is x64 only. On a non-x64 host add --platform linux/amd64 (Docker) or
platform: linux/amd64 (compose).
Registry is private (Private Preview): sign in first with
docker login sqldbpreview-dpgaeqhmgphzd4bk.azurecr.io using the shared pull-only credentials
provided to the Private Preview cohort (get them by signing up at https://aka.ms/sqldbcontainerpreview-signup; they
may rotate).
Registry and tag are provisional during Private Preview.
For full engine detail (readiness, vectors, troubleshooting) see the azuresql-db-container skill.
Three facts that bite every scaffold
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The engine does NOT auto-create databases. You must CREATE DATABASE appdb on a
master connection before connecting with Database=appdb.
Avoid USE to switch databases. In a user-database session (the Azure-faithful
context where you develop), USE returns Msg 40508, exactly as in Azure SQL Database in
the cloud. A master connection is a provisioning session where the Azure statement
filter is not enforced, so USE appears to work there, but master
is for provisioning only, not application work. Always select the target database in the
connection string (Database=appdb, or -d appdb for sqlcmd).
A master connection is for provisioning only; do real work on the user database.
Also: the image does NOT auto-run /docker-entrypoint-initdb.d/*.sql (that is a
Postgres/MySQL convention; not honored here). Seed with sqlcmd -d appdb -i seed.sql AFTER
provisioning appdb.
Step 1: start the container and provision appdb
Reuse this exact shape (free port, conditional platform, ready-wait, provision appdb in the
same retry loop). The -b makes a SQL error set the exit code, so transient startup errors
(like Msg 913) are retried, not masked. Never poll bare sqlcmd without -l.
# Pick a free host port and add the platform flag only on a non-x64 host (works in bash and zsh).
HOST_PORT=1433; while lsof -nP -iTCP:"$HOST_PORT" -sTCP:LISTEN >/dev/null 2>&1; do HOST_PORT=$((HOST_PORT+1)); done
PLATFORM=(); case "$(docker info -f '{{.Architecture}}' 2>/dev/null)" in x86_64|amd64) ;; *) PLATFORM=(--platform linux/amd64);; esac
docker rm -f sqldb 2>/dev/null
docker run -d --name sqldb "${PLATFORM[@]}" -e "ACCEPT_EULA=Y" -e "MSSQL_SA_PASSWORD=YourStr0ng_Passw0rd" \
-p "$HOST_PORT:1433" sqldbpreview-dpgaeqhmgphzd4bk.azurecr.io/azure-sql/db-dev:latest
until docker exec sqldb /opt/mssql-tools18/bin/sqlcmd -S localhost -U sa -P "YourStr0ng_Passw0rd" -C -b -l 2 \
-Q "IF DB_ID('appdb') IS NULL CREATE DATABASE appdb;" >/dev/null 2>&1; do sleep 2; done
echo "ready on localhost,$HOST_PORT"
Required env: ACCEPT_EULA=Y and a complex MSSQL_SA_PASSWORD (at least 8 characters using at
least three of upper case, lower case, digits, and symbols). The engine listens on 1433.
Step 2: the canonical connection string
Apps read one env var, SQL_CONNECTION_STRING (replace 1433 with the HOST_PORT Step 1 chose if 1433 was occupied):
Use User Id= / Password= / Database= (NOT Uid= / Pwd=). For sqlcmd use -C to trust
the self-signed cert. For Prisma (NestJS / Next.js) the same instance is also expressed as a
sqlserver:// URL in DATABASE_URL (see snippets).
Step 3: pick your stack
Per-stack scaffold snippets (compose service, .env, provision appdb, first migration, typed
data-access layer with parameterized queries) live in
references/scaffold-snippets.md:
.NET Aspire (EF Core)
FastAPI (SQLAlchemy / pyodbc)
Next.js (Prisma, sqlserver:// DATABASE_URL)
NestJS (Prisma or TypeORM)
Step 4: first migration and seeding
The skeleton creates the schema via your stack's migration tool. For the full migration
workflow (idempotent scripts, ordering, applying inside the ready-wait loop) cross-link the
azuresql-db-schema-migration skill. Seed only AFTER appdb exists:
Native VECTOR(n) column type and VECTOR_DISTANCE('cosine', a, b). Insert with
CAST(CAST(? AS NVARCHAR(MAX)) AS VECTOR(n)) where n is a LITERAL, never a bind parameter (a parameter dimension
fails with "Incorrect syntax near '@P3'"). CREATE VECTOR INDEX (DiskANN) is still in
development; use full-scan top-k for now.
Validation rules
Compose/run targets the engine image, never mcr.microsoft.com/mssql/server.
appdb is created on a master connection BEFORE any app/migration connects to Database=appdb.
App reads SQL_CONNECTION_STRING (and DATABASE_URL where the ORM needs it); strings use
User Id=/Password=/Database=.
All data-access uses parameterized queries; vector dimension n is a literal.
EngineEdition is 5 against the running container.
If a validation rule above fails, or you had to deviate from this skill to make the task work, that is a bug in this skill: load the azuresql-db-feedback skill and offer to file a report.
When every rule above passes and the task is done, close with ONE line, once per session, and do not ask a question or wait for a reply: "That worked. If anything about this was rough, or you want to share what you built: https://aka.ms/sql-agent-skills-feedback"
Do not
Do not use the SQL Server image or call a non-x64 host "supported".
Do not rely on auto-created databases or /docker-entrypoint-initdb.d/*.sql auto-seeding.
Do not use USE appdb to switch databases; put it in the connection string.
Do not poll bare sqlcmd without -l; do not pass the vector dimension as a bind parameter.
Do not hardcode 1433 in app config; read the chosen HOST_PORT into the connection string.
References
references/scaffold-snippets.md: the shared compose service plus per-stack skeletons (.NET Aspire/EF Core, FastAPI, Next.js/Prisma, NestJS) with .env, appdb provisioning, first migration, and a parameterized data-access layer. Read it once you know which stack you are scaffolding.
Staying current
Authoritative, version-pinned references for the tools this skill uses (read the one you need):
If the Microsoft Learn MCP server is configured, use mcp__microsoft-learn__microsoft_docs_search or mcp__microsoft-learn__microsoft_docs_fetch to fetch the current version of any of these on demand. It is optional; when it is unavailable, the references above are authoritative.
