> ## Documentation Index
> Fetch the complete documentation index at: https://agents.nanonets.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# SQL Server Execute Query

> Read-only SQL query tool for Microsoft SQL Server exposed through the Agents Platform.

This document covers `mssql_execute_query`, the read-only SQL query tool for Microsoft SQL Server exposed through the Agents Platform.

## Authentication

`mssql_execute_query` connects to a customer's own SQL Server (SQL Authentication only — username/password, not Windows/Azure AD auth) via the generic **integrations** config form. Users configure:

* `host`, `port` (default `1433`), `database`, `username`, `password`
* `encrypt` — `disable`, `true` (TLS required), or `strict` (TDS 8.0, verify certificate). Default `true`.
* `trust_server_certificate` — trust the server's TLS certificate without CA verification. Default `false`. Enable this for an on-prem server with a self-signed certificate (`encrypt: true` + `trust_server_certificate: true`); otherwise the connection fails with a certificate-verification error.
* `host_name_in_certificate` — optional, only relevant when validating a certificate whose SAN doesn't match the connection host.
* `schema` — optional namespace. Leave empty to use the default `dbo` schema.

All of these fields are injected by the platform from the stored integration at call time (`x-variable-service: "mssql"`) — they are not entered per run.

## `mssql_execute_query`

Executes a read-only SQL query against a SQL Server database and returns the results as structured rows.

### Inputs

Required:

* `query`: SQL query to execute. **SELECT statements only** — see below.

Optional:

* `max_rows`: Maximum rows to return (defaults to 3000 when unset or `0`; a caller-supplied value above 3000 is honored as-is, not clamped).

### SELECT-only enforcement

Only statements starting with `SELECT` (after trimming whitespace) are accepted; anything else is rejected before a connection is even opened. Use [`mssql_upsert`](/docs/tools/mssql_upsert) for writes — its `query` field accepts arbitrary INSERT/UPDATE/DELETE/MERGE statements when the structured upsert path can't express what you need.

### Schema qualification

SQL Server has no `search_path` equivalent, so unlike some other database connectors this tool never sets a session-level default schema. Reference tables with the schema explicit in the query (`SELECT * FROM dbo.orders` or `SELECT * FROM sales.orders`) — the configured `schema` field only affects credential defaults surfaced elsewhere (e.g. `mssql_upsert`'s generated statements), not what you write in a raw `query` here.

### Output

On success, structured content includes:

* `columns`: column names, in result order
* `rows`: array of column → value objects
* `row_count`: number of rows returned (after truncation)
* `truncated`: `true` if more rows existed than `max_rows` allowed
* `database`, `host`: the database/host queried
* `max_rows`: the effective cap applied

### Notes

* A `uniqueidentifier` column comes back as a standard GUID string (e.g. `"01234567-89AB-CDEF-0123-456789ABCDEF"`), not raw bytes — the tool decodes SQL Server's internal mixed-endian byte layout for you.
* Every query execution emits a HIPAA audit event (`external_call`, provider `mssql`) recording the host, latency, and outcome — see [SQL Server Upsert](/docs/tools/mssql_upsert#notes) for the same on the write path.