Reviewed October 6, 2026.
Choose the database that owns your data
The same business question can require different query syntax and connection settings. Begin with your engine and version. The links below lead to the relevant SQL examples or warehouse setup, so you can use details that match your environment.
PostgreSQL
Generate PostgreSQL SQL; check JSONB, schema qualification, latest-row selection and time zones.
MySQL
Generate MySQL SQL; check JSON types, NULL comparisons, SQL mode and server version.
SQL Server
Use T-SQL syntax. TOP and date functions differ from PostgreSQL and MySQL.
BigQuery
Prepare project and credentials context; check dataset permissions, nested arrays and query costs.
Snowflake
Choose the database, schema, role and warehouse; verify access and historical row versions.
MongoDB uses document queries and aggregation pipelines rather than ordinary relational SQL. Check the connection guide for available connectors and setup. Connecting several systems does not automatically let a single query join their data. Arrange an approved reporting layer when an analysis spans separate sources.
If you already know your SQL dialect, go directly to the general SQL construction example. For a broader explanation of the approach, read natural-language database querying.
Turn a question into a checked database query
- Connect an approved reporting source. Use the connection fields for your database and an account limited to the intended tables or views. Desktop connects from your computer; hosted Chatbot uses its server-side connection path.
- Explain the business meaning. Identify the entity being counted, relationships, units, date scope and exclusions. Table names alone do not explain whether a reservation is still open or whether a stock value is current.
- Ask for an inspectable answer. Specify columns, grouping, order and a reasonable output limit. Ask the assistant to state assumptions. Inspect the generated SQL and results in the connected workflow; do not rely on a prompt to prevent unwanted access.
- Reconcile and refine. Compare the result with a small known case. Then ask a follow-up, such as changing the output size, and confirm that the original filters and metric definition remain intact.
The database context and follow-up guide explains how to prepare reusable context. Training data and documentation can supply approved business definitions; they do not replace database permissions or guarantee correctness.
A query brief you can adapt
Database: PostgreSQL; use my approved reporting tables.
One query_items row per SKU; on_hand is the current stock snapshot.
Reservations: one row per reservation; only status = 'open' counts.
Available units = on_hand minus the sum of open reservation quantities.
Include active = 1 only. Exclude unknown (NULL) on_hand and flag that exclusion.
Find items below their own reorder_point.
Return SKU, available units, reorder point; at most two rows.
Sort by available units ascending, then SKU ascending to break ties.
Keep negative availability visible. Do not make inventory changes.
Explain assumptions and show the SQL alongside the result.Use approved schema descriptions, not passwords or connection secrets, in a question. Replace fictional table names with the real reporting objects. If the inventory is split by warehouse, add that key to both the grain and the join; a SKU-only join would answer a different question.
Worked example: which items need replenishment?
A request for the “two lowest-stock items” leaves important decisions open. Here, available stock means current on-hand units minus open reservations. Include only active items below their individual reorder point, exclude unknown stock, and sort ties by SKU. Negative availability remains visible as a shortage.
This fictional dataset has five items. A has ten units and two open reservations totaling seven. B has three units and a cancelled reservation that must not count. C has no stock or reservations. D is inactive. E has an unknown stock value, which is not treated as zero.
Show the disposable reference fixture
-- Synthetic reference data. Use a disposable PostgreSQL test session.
CREATE TEMP TABLE query_items (
sku TEXT PRIMARY KEY, on_hand INTEGER,
reorder_point INTEGER NOT NULL, active INTEGER NOT NULL
);
CREATE TEMP TABLE query_reservations (
reservation_id INTEGER PRIMARY KEY, sku TEXT,
quantity INTEGER NOT NULL, status TEXT NOT NULL
);
INSERT INTO query_items VALUES
('A', 10, 5, 1), ('B', 3, 8, 1), ('C', 0, 2, 1),
('D', 50, 60, 0), ('E', NULL, 5, 1);
INSERT INTO query_reservations VALUES
(1, 'A', 4, 'open'), (2, 'A', 3, 'open'),
(3, 'B', 9, 'cancelled'), (4, 'D', 10, 'open');PostgreSQL reference SQL
WITH open_reservations AS (
SELECT sku, SUM(quantity) AS reserved_units
FROM query_reservations
WHERE status = 'open'
GROUP BY sku
)
SELECT i.sku,
i.on_hand - COALESCE(r.reserved_units, 0) AS available_units,
i.reorder_point
FROM query_items AS i
LEFT JOIN open_reservations AS r ON r.sku = i.sku
WHERE i.active = 1
AND i.on_hand IS NOT NULL
AND i.on_hand - COALESCE(r.reserved_units, 0) < i.reorder_point
ORDER BY available_units ASC, i.sku ASC
LIMIT 2;| SKU | Available units | Reorder point |
|---|---|---|
| C | 0 | 2 |
| A | 3 | 5 |
C comes first at zero units. A and B both have three, so the explicit SKU tie-break selects A for the second row. Increasing the limit to three includes B. Without that tie-break, a two-row result would not specify which tied item belongs in the answer.
Reservations are summed before joining so each item contributes one row. Counting reservation records instead of summing quantities would give A eight available units instead of three. Treating missing stock as zero would bring E into the report and conceal a data-quality problem. Review those decisions before acting on replenishment advice.
The reference was executed locally in PostgreSQL 18.3 through PGlite 0.5.8 using only synthetic data. Checks cover tied rows, cancelled reservations, unknown stock, inactive items, an empty result and changed reservations. This verifies the reference SQL, not AI accuracy or your live database. Temporary tables here are for a disposable test session, not an import method for a separate application connection.
Keep the meaning when changing SQL dialects
| Engine | Row-limit syntax | What else to check |
|---|---|---|
| PostgreSQL | LIMIT 2 after ORDER BY | Schema names, column types and a complete ordering. |
| MySQL | LIMIT 2 after ORDER BY | Server version, SQL mode and support for the query constructs used. |
| SQL Server | SELECT TOP (2) in the outer query; omit LIMIT | T-SQL object names and the same ORDER BY keys. |
| BigQuery | LIMIT 2 after ORDER BY | Project/dataset qualification, GoogleSQL types and bytes processed. |
This table is a syntax guide, not a claim that the fixture ran on every engine. Compare PostgreSQL LIMIT, MySQL SELECT, SQL Server TOP and BigQuery query syntax. A dialect change requires checking the whole query, including date arithmetic, JSON and identifiers.
Choose the workflow and validate its boundaries
A disconnected text-to-SQL tool is useful when you want a draft from an approved schema description. A connected assistant is useful when you need to inspect results and ask follow-ups. A visual query builder exposes columns, joins and filters through controls. AskYourDatabase focuses on conversational querying; this page does not promise a drag-and-drop designer or an unrestricted free service.
For correctness, check missing values, duplicate relationships, units and tie rules against an independent answer. The text-to-SQL evaluation kit provides a broader acceptance process. Record failures and clarifications as well as successful queries.
For access, enforce restrictions through approved database accounts, views and the applicable application controls. Read-only access limits writes but may still expose too many rows. Generated SQL, an instruction in the prompt and a small result limit do not establish authorization.
For cost, check the execution plan and warehouse controls with the database owner. Returning two inventory rows may still require aggregating every open reservation. For data handling, review security and model data flow: local database connectivity does not mean local inference. Questions, schema and selected results can reach external services. Evaluate the actual model endpoint and retained records for private deployments.
Once the reporting query is accepted, the SQL dashboard guide shows how to validate repeated reporting. Customer-facing access requires a separate embedded chatbot evaluation, including user and tenant boundaries.
Database query generator FAQs
What does a database query generator do?
It turns a request and database context into a query. AskYourDatabase uses a connected workflow: ask about approved tables, inspect SQL and results, and refine the question in conversation. A generated query still needs a known-answer check.
How is this different from a database generator?
A query generator reads or operates on an existing database. A database or test-data generator creates structures or sample records. This page covers querying existing data; it does not offer a synthetic-data generation service or schema migration tool.
Which database should I select?
Select the engine that stores your data, not the language in which you ask the question. PostgreSQL, MySQL and SQL Server use different SQL features. BigQuery and Snowflake also require warehouse-specific configuration. Confirm your engine and version with the database owner.
Is there a free query generator on this page?
You can read and copy the reference examples here without an account. This page does not execute AI requests or connect to your database in the browser. Use the Desktop download and current pricing page to check product access and plan terms.
Can one generated query join separate database servers?
Supporting several database connectors does not establish automatic federation across servers. Use tables available through the selected connection, or an approved reporting layer that already makes the required data queryable. Validate that architecture before requesting a cross-source join.
Does a row limit make a query inexpensive?
No. A small result can still require scanning or aggregating a large input. Inspect the plan and relevant warehouse cost controls. Also specify a complete ordering so that repeated queries select the intended rows when values tie.
Will Desktop keep every part of the query local?
Desktop connects to the database from your computer, but questions, schema context and selected results can be included in external model requests. Hosted Chatbot and private deployments have different paths. Review security and deployment documentation for your chosen configuration.
Start with one question you can verify
Download AskYourDatabase Desktop, select your approved database and test a question with a known answer. Review current plans for your chosen workflow, or discuss a private deployment with the team before connecting restricted data.
