X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=README.md;h=2f543b96e5ff9a1221131b3c3311935666db549e;hb=b8af38fdc3c2f56ffbf4f0be715742152a3f37c8;hp=93b13149d1c9970bff222fe231a276f28126ca54;hpb=fe021b27455df1f9cd8392b2bba235029c567dec;p=erdiag.git diff --git a/README.md b/README.md index 93b1314..2f543b9 100644 --- a/README.md +++ b/README.md @@ -5,27 +5,28 @@ Inspired by [this repository](https://code.google.com/archive/p/merisier/). This parser reads ER diagrams definition files, and produces two types of diagrams + SQL code. [Graphviz](https://www.graphviz.org/) is used on server side to translate parsed graph descriptions into SVG objects. -*Note:* at the moment, only the conceptual graph is implemented, and no comments are allowed in textual descriptions. -At least the former is planned, and also probably a way to indicate relative identifiers. +*TODO list:* functional integrity constraints (CIF), inter-relations constraints (or, and, xor...), inheritance with the right symbol (triangle). + +*Note:* temporary dependency to [underscore](http://underscorejs.org/); good library but used so far only for its shuffle() method. ----- An entity is defined as follow - [Entity] - #attr1 (*) - attr2 (*) + [Entity] + #attr1 (*) + attr2 (*) with (\*) = optional SQL indications, and # denoting a (part of) a key. A relationship is defined in this way - {Relation} - Entity C1 - Entity2 C2 - -- - attr1 (*) - attr2 (*) + {Relation} + Entity C1 + Entity2 C2 + -- + attr1 (*) + attr2 (*) where attributes are optional, and C1 (resp. C2) = cardinality for entity 1 (resp. 2). Defining relationships with more than two attributes is easy: just add entities. @@ -35,6 +36,8 @@ Cardinality dictionary: * 1 = 1..1 * ? = 0..1 +Special cardinalities are also available to indicate relative identification: `?R` and `1R`. + To mark a weak entity, just surround its name by extra-brackets [[WeakEntity]] @@ -47,11 +50,11 @@ The syntax for these two last is then the same as in the non-weak versions. To indicate an inheritance relation, proceed as follow - is_a - Animal Cat Fish - Planet Mars Venus + is_a + Animal Cat Fish + Planet Mars Venus -Finally, blocks must be separated by new lines. For a usage example, see example.html (it should render as seen in example.svg) +Finally, blocks must be separated by new lines. For a usage example, see example.html (it should render as seen in example\_\*.svg) Note that the "drawMcd" method can take a second argument, which indicates the type of graph. * "bubble" draws the standard graph, as seen [here](https://en.wikipedia.org/wiki/Entity%E2%80%93relationship_model#/media/File:ER_Diagram_MMORPG.png) for example