{ "slug": "er-diagram-from-sql", "name": "gizza-ai/er-diagram-from-sql", "version": "0.1.0", "title": "ER Diagram from SQL — CREATE TABLE DDL to Mermaid erDiagram — gizza.ai", "description": "Paste SQL CREATE TABLE / ALTER TABLE DDL and get Mermaid erDiagram code with entities, typed columns, PK/FK/UK markers, and crow's-foot relationships.", "tags": [ "er diagram from sql", "sql to mermaid", "sql to erd", "mermaid erdiagram generator", "create table to diagram", "database schema diagram", "ddl to er diagram", "entity relationship diagram generator", "sql schema visualizer" ], "category": "developer", "urls": { "page": "https://gizza.ai/tools/er-diagram-from-sql/", "markdown": "https://gizza.ai/tools/er-diagram-from-sql/index.md", "descriptor": "https://gizza.ai/tools/er-diagram-from-sql/tool.json", "deep_link_example": "https://gizza.ai/tools/er-diagram-from-sql/?sql=CREATE%20TABLE%20users%20%28%0A%20%20id%20INT%20PRIMARY%20KEY%2C%0A%20%20email%20VARCHAR%28255%29%20NOT%20NULL%20UNIQUE%0A%29%3B%0ACREATE%20TABLE%20orders%20%28%0A%20%20id%20INT%20PRIMARY%20KEY%2C%0A%20%20user_id%20INT%20NOT%20NULL%20REFERENCES%20users%28id%29%2C%0A%20%20total%20DECIMAL%2810%2C2%29%0A%29%3B&dialect=auto&attributes=all&key_markers=true&mark_nullable=true&infer_relations=true&relationship_label=column&direction=auto&fence=true" }, "cli": "gizza tool er-diagram-from-sql \"CREATE TABLE users (\n id INT PRIMARY KEY,\n email VARCHAR(255) NOT NULL UNIQUE\n);\nCREATE TABLE orders (\n id INT PRIMARY KEY,\n user_id INT NOT NULL REFERENCES users(id),\n total DECIMAL(10,2)\n);\"", "tool": { "description": "Turn SQL DDL into a Mermaid ER diagram. Paste CREATE TABLE statements (ALTER TABLE ... ADD FOREIGN KEY and CREATE UNIQUE INDEX are folded in) and it emits erDiagram source: one entity per table, its columns as 'TYPE name' attributes with PK / FK / UK markers, and one crow's-foot relationship per foreign key. Cardinality is derived from the schema — the parent side is '||' (exactly one) when every FK column is NOT NULL and '|o' (zero or one) otherwise; the child side is 'o{' (zero or more), or 'o|' when the FK columns are themselves unique in the child (a 1:1); the line is solid '--' for a NOT NULL FK and dashed '..' for a nullable one. Options: limit attributes to keys only or hide them entirely for wide schemas, toggle the PK/FK/UK markers, mark nullable columns with Mermaid's 'TYPE?' form, infer relationships from '_id' columns that lack a foreign key, label relationships by column or by constraint name (or not at all), set a layout direction, and wrap the result in a ```mermaid code fence. Types and identifiers are sanitized to Mermaid-safe tokens (DECIMAL(10,2) becomes DECIMAL(10_2), TIMESTAMP WITH TIME ZONE becomes TIMESTAMP_WITH_TIME_ZONE) so the diagram actually renders. Supports MySQL, PostgreSQL, SQLite, SQL Server and generic dialects. It is a lenient text parser, not a SQL engine: comments and non-DDL statements are skipped and nothing is executed. It emits diagram source, not an image; paste it anywhere Mermaid renders. Maximum 500 tables.", "parameters": { "additionalProperties": false, "properties": { "attributes": { "default": "all", "description": "Which columns to list inside each entity block. 'all' (default) lists every column as 'TYPE name'. 'keys' keeps only primary-key, foreign-key and unique columns, which keeps a wide schema readable. 'none' emits bare entity names plus the relationship lines only. Default all.", "enum": [ "all", "keys", "none" ], "type": "string" }, "dialect": { "default": "auto", "description": "SQL dialect hint. Identifiers are normalized for every dialect (backticks, \"double quotes\" and [brackets] are stripped); this mainly controls whether '#' starts a line comment (mysql/auto). Default auto.", "enum": [ "auto", "mysql", "postgres", "sqlite", "mssql", "generic" ], "type": "string" }, "direction": { "default": "auto", "description": "Layout direction emitted as a 'direction' statement inside the diagram: LR (left to right), RL, TB (top to bottom, TD is accepted as an alias) or BT. 'auto' (default) omits the statement and lets the renderer choose. Default auto.", "enum": [ "auto", "LR", "RL", "TB", "BT" ], "type": "string" }, "fence": { "default": false, "description": "Wrap the diagram in a ```mermaid code fence so it can be pasted straight into a Markdown file, a GitHub issue or a pull-request comment. Default false (bare diagram source).", "type": "boolean" }, "infer_relations": { "default": false, "description": "Also draw a relationship for a '_id' column that has no explicit FOREIGN KEY, when '' (or its plural) matches a table in the same DDL — useful for schemas that enforce references in the application instead of the database. Never duplicates an explicit foreign key. Default false.", "type": "boolean" }, "key_markers": { "default": true, "description": "Append Mermaid's PK / FK / UK markers to attribute lines (e.g. 'INT user_id FK'). UK is only added for single-column uniqueness, since a member of a composite UNIQUE is not unique on its own. Ignored when attributes is 'none'. Default true.", "type": "boolean" }, "mark_nullable": { "default": false, "description": "Render nullable columns with Mermaid's optional-attribute form 'TYPE? name' so NULL-able columns are visible in the diagram. Default false.", "type": "boolean" }, "relationship_label": { "default": "column", "description": "What to write after the ':' on each relationship line. 'column' (default) uses the foreign-key column name(s). 'constraint' uses the FOREIGN KEY constraint name, falling back to the columns when it is unnamed. 'none' emits an empty label, which keeps a busy diagram clean. Default column.", "enum": [ "column", "constraint", "none" ], "type": "string" }, "sql": { "description": "The SQL DDL to diagram. Include one or more CREATE TABLE statements (ALTER TABLE ... ADD FOREIGN KEY and CREATE UNIQUE INDEX are folded in) — e.g. \"CREATE TABLE users (id INT PRIMARY KEY); CREATE TABLE orders (id INT PRIMARY KEY, user_id INT NOT NULL REFERENCES users(id));\". Comments and non-DDL statements (INSERT, SELECT, ...) are ignored and nothing is executed. Maximum 500 tables.", "type": "string" } }, "required": [ "sql" ], "type": "object" } } }