Convert SQL `CREATE TABLE` statements into a clear ER diagram online. Visualize tables, foreign keys, and schema relationships without leaving the browser.
These pages solve adjacent but different problems. This tool is strongest when the immediate need is visual schema understanding, not migration comparison or query performance diagnosis.
Best when you need to see table relationships, foreign-key paths, and model shape quickly.
Best when the question is not “what does this schema look like?” but “what changed between version A and version B?”
Best when the schema is already known and the next problem is query cost, scan risk, or indexing pressure.
Next Step
Once the relationship graph is clear, most users need one of three follow-ups: compare revisions, inspect query behavior against the model, or switch to a broader starting path if they are still figuring out the job to be done.
Go here when the real question is not model shape anymore, but what changed between two versions.
Open Schema DiffAnalyzeMove here when the schema is understandable but join cost, scan risk, or missing indexes are still open questions.
Open Query AnalyzerRoute meOpen Start Here when you are bouncing between tools because the real need is lessons, practice, or a more direct entry point.
Open Start HereThe diagram is useful because it converts raw DDL into visible ownership and dependency paths. In this simple example, one customer can own many orders, and one order can own many order items.
Example Input SQL
CREATE TABLE customers (
id INTEGER PRIMARY KEY,
name TEXT
);
CREATE TABLE orders (
id INTEGER PRIMARY KEY,
customer_id INTEGER,
total_amount NUMERIC,
FOREIGN KEY (customer_id) REFERENCES customers(id)
);
CREATE TABLE order_items (
id INTEGER PRIMARY KEY,
order_id INTEGER,
sku TEXT,
quantity INTEGER,
FOREIGN KEY (order_id) REFERENCES orders(id)
);What the diagram reveals
orders.customer_id -> customers.id signals a one-to-many path from customer to orders.order_items.order_id -> orders.id signals a second one-to-many path from order to line items.Paste raw CREATE TABLE statements and turn them into something you can reason about without reading every DDL block manually.
The diagram is generated in the browser, so internal schema details do not need to be uploaded to a third-party service.
Use SVG exports in architecture docs, pull requests, and tickets when the schema needs a visual artifact rather than another SQL paste.
An ER diagram is most useful before implementation is locked in. It gives you a fast structural checkpoint between raw DDL and the deeper work of migration planning, indexing, and query review.
Useful when you inherit raw CREATE TABLE statements and need a visual map before changing anything.
Best when you are still shaping a schema and want to see whether the model is readable before it lands in migrations.
Entity-Relationship diagrams are not just presentation assets. They are one of the fastest ways to see whether a schema communicates its intent clearly. Once tables and references are visible together, it becomes easier to spot weak naming, missing foreign keys, suspicious bridge tables, or parts of the model that have become too tightly coupled.
Most production schemas repeat a small set of patterns. One-to-many relationships are the default shape for operational systems. One-to-one is rarer and usually signals optional detail or profile-style extension. Many-to-many relationships almost always introduce a junction table, which is exactly the kind of thing a diagram makes obvious at a glance.
A clean diagram is not enough on its own. It does not tell you whether foreign key columns are indexed, whether a hot reporting query will scan millions of rows, or whether a migration from one version of the schema to another is safe. That is why schema visualization should sit alongside tools like Schema Diff and Query Analyzer rather than replace them.
These are the practical signals the diagram can surface quickly before you move into migrations or performance work.
Columns named user_id or order_id are not enough by themselves. The diagram becomes trustworthy when the schema defines actual foreign key constraints.
If you see a small bridge table connecting two larger entities, you are usually looking at a many-to-many model. That is often a sign to check uniqueness and indexing carefully.
A neat ER diagram can still hide expensive joins or missing indexes. Pair schema visualization with index review and query analysis before shipping.
A visual schema review usually reveals one of three things: the model is still unstable, the relationships are unclear, or the data boundaries themselves need rethinking.
Use this path when the diagram is helping you check entity boundaries and relationship shape before schema changes harden into DDL.
Relevant when the picture is readable but you still need better intuition for junction tables, ownership, and one-to-many vs many-to-many choices.
Choose this route when the diagram is surfacing privacy boundaries or the question of what belongs in relational columns versus JSON.
These guides help when the visual model raises questions about normalization, table relationships, or how schema choices affect query behavior.
Good foundation when you are still deciding how entities and relationships should be split.
Helpful when the ER diagram suggests duplicated attributes or overly wide tables.
Best follow-up when you want clearer intuition for one-to-one, one-to-many, and many-to-many design.
Useful when the visual model raises the question of what should stay relational and what can remain semi-structured.
Relevant when schema boundaries should help isolate sensitive columns before data reaches lower environments.
Relevant when foreign keys and join paths are clear, but query performance still needs work.
The diagram parser looks for explicit FOREIGN KEY definitions. Naming a column user_id suggests intent, but it does not prove the relationship structurally.
The tool is strongest on standard CREATE TABLE syntax and common MySQL or PostgreSQL patterns. Logical schema details matter more than vendor-specific storage options for this visualization step.
Yes. Exporting to SVG is the right choice for internal documentation because the diagram stays sharp in design docs, wikis, and review threads.
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