Merge pull request #3 from malcolm-kee/v2

v2: Support Join

.eslintrc.json

@@ -0,0 +1,14 @@
+{
+  "extends": ["eslint:recommended"],
+  "parserOptions": {
+    "ecmaVersion": 2017
+  },
+  "env": {
+    "node": true,
+    "es6": true,
+    "jest": true
+  },
+  "rules": {
+    "no-console": ["error", { "allow": ["error"] }]
+  }
+}

.travis.yml

@@ -0,0 +1,3 @@
+language: node_js
+node_js:
+  - '8'

README.md

@@ -19,82 +19,167 @@ module.exports = {
           password: 'db-password',
           database: 'world'
         },
-        query: 'SELECT * FROM city',
-        idFieldName: 'ID'
+        queries: [
+          {
+            statement: 'SELECT * FROM country',
+            idFieldName: 'Code',
+            name: 'country'
+          }
+        ]
       }
     }
     // ... other plugins
   ]
 };
 ```
 
+And then you can query via GraphQL with the type `allMysql<Name>` where `<Name>` is the `name` for your query.
+
+Below is a sample query, however, it is probably different from yours as it would dependent on your configuration and your SQL query results.
+
+Use [GraphiQL](https://www.gatsbyjs.org/docs/introducing-graphiql/) to explore the available fields.
+
+```graphql
+query {
+  allMysqlCountry {
+    edges {
+      node {
+        Code
+        Name
+        Population
+      }
+    }
+  }
+}
+```
+
 ### multiple queries
 
-When you have multiple queries, include the plugins multiple times with different `typePrefix`.
+When you have multiple queries, add another item in the `queries` option with different `name`.
 
 ```javascript
+// In your gatsby-config.js
 module.exports = {
   plugins: [
     {
-      resolve: 'gatsby-source-mysql',
+      resolve: `gatsby-source-mysql`,
       options: {
         connectionDetails: {
           host: 'localhost',
-          user: 'malcolm',
-          password: 'password',
+          user: 'db-username',
+          password: 'db-password',
           database: 'world'
         },
-        query: 'SELECT * FROM city',
-        idFieldName: 'ID',
-        typePrefix: 'City'
+        queries: [
+          {
+            statement: 'SELECT * FROM country',
+            idFieldName: 'Code',
+            name: 'country'
+          },
+          {
+            statement: 'SELECT * FROM city',
+            idFieldName: 'ID',
+            name: 'city'
+          }
+        ]
       }
-    },
+    }
+    // ... other plugins
+  ]
+};
+```
+
+### joining queries
+
+It's possible to join the results of the queries by providing `parentName`, `foreignKey`, and `cardinality` to the query object.
+
+> Currently only one-to-one and one-to-many relationship are supported. If you have a use case for many-to-many relationship, [raise an issue][raise-issue], and I'll look into it.
+
+```javascript
+// In your gatsby-config.js
+module.exports = {
+  plugins: [
     {
-      resolve: 'gatsby-source-mysql',
+      resolve: `gatsby-source-mysql`,
       options: {
         connectionDetails: {
           host: 'localhost',
-          user: 'malcolm',
-          password: 'password',
+          user: 'db-username',
+          password: 'db-password',
           database: 'world'
         },
-        query: 'SELECT * FROM country',
-        idFieldName: 'Code',
-        typePrefix: 'Country'
+        queries: [
+          {
+            statement: 'SELECT * FROM country',
+            idFieldName: 'Code',
+            name: 'country'
+          },
+          {
+            statement: 'SELECT * FROM city',
+            idFieldName: 'ID',
+            name: 'city',
+            parentName: 'country',
+            foreignKey: 'CountryCode',
+            cardinality: 'OneToMany'
+          }
+        ]
       }
     }
     // ... other plugins
   ]
 };
 ```
 
-## Plugin options
-
-As this plugin is a wrapper of the popular [`mysql`](https://www.npmjs.com/package/mysql) library, the options are based on the library.
-
-- **connectionDetails** (required): options when establishing the connection. Refer to [`mysql` connection options](https://www.npmjs.com/package/mysql#connection-options)
-- **query** (required): the SQL query statement to be executed.
-- **idFieldName** (required): column that is unique for each record. This column must be included in the `query`.
-- **typePrefix** (optional): the prefix of the data source in the GraphQL schema. Default to `MySql`.
-
-## How to query your data using GraphQL
-
-The GraphQL type would be follow the format of `all<typePrefix>Results`.
-
-Below is a sample query, however, it is probably different from yours as it would dependent on your configuration and your SQL query results.
+In the example above, `country` and `city` is one-to-many relationship (one country to multiple cities), and they are joined with `country.Code = city.CountryCode`.
 
-Use [GraphiQL](https://www.gatsbyjs.org/docs/introducing-graphiql/) to explore the available fields.
+With the configuration above, you can query a country joined with all the related cities with
 
 ```graphql
 query {
-  allCountryResults {
+  allMysqlCountry {
     edges {
       node {
         Code
         Name
         Population
+        cities {
+          Name
+        }
+      }
+    }
+  }
+}
+```
+
+It also works the other way, i.e. you can query the country when getting the city
+
+```graphql
+query {
+  allMysqlCity {
+    edges {
+      node {
+        Name
+        country {
+          Name
+        }
       }
     }
   }
 }
 ```
+
+## Plugin options
+
+- **connectionDetails** (required): options when establishing the connection. Refer to [`mysql` connection options](https://www.npmjs.com/package/mysql#connection-options)
+- **queries** (required): an array of object for your query. Each object could have the following fields:
+
+| Field         | Required? | Description                                                                                                                                                                                |
+| ------------- | --------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| `statement`   | Required  | the SQL query statement to be executed.                                                                                                                                                    |
+| `idFieldName` | Required  | column that is unique for each record. This column must be returned by the `statement`.                                                                                                    |
+| `name`        | Required  | name for the query. Will impact the value for the graphql type                                                                                                                             |
+| `parentName`  | Optional  | name for the parent entity. In a one-to-many relationship, this field should be specified on the child entity (entity with many records).                                                  |
+| `foreignKey`  | Optional  | foreign key to join the parent entity.                                                                                                                                                     |
+| `cardinality` | Optional  | the relationship between the parent and this entity. Possible values: `"OneToMany"`, `"OneToOne"`. Default to `"OneToMany"`. (Note: many-to-many relationship is currently not supported.) |
+
+[raise-issue]: https://github.com/malcolm-kee/gatsby-source-mysql/issues/new

gatsby-node.js

@@ -1,39 +1,24 @@
-const createNodeHelpers = require('gatsby-node-helpers').default;
-const mysql = require('mysql');
+const queryDb = require('./src/db');
+const createMysqlNodes = require('./src/create-mysql-nodes');
 
-exports.sourceNodes = ({ actions }, configOptions) => {
+exports.sourceNodes = async ({ actions }, configOptions) => {
   const { createNode } = actions;
-  const {
-    connectionDetails,
-    query,
-    idFieldName = 'id',
-    typePrefix = 'MySql'
-  } = configOptions;
-  const { createNodeFactory } = createNodeHelpers({
-    typePrefix
-  });
+  const { connectionDetails, queries } = configOptions;
 
-  const MySqlNode = createNodeFactory('Results');
+  const { db, queryResults } = await queryDb(connectionDetails, queries);
 
-  const dbConnection = mysql.createConnection(connectionDetails);
+  try {
+    queries
+      .map((query, index) =>
+        Object.assign({}, query, { __sqlResult: queryResults[index] })
+      )
+      .forEach((sqlResult, _, sqlResults) =>
+        createMysqlNodes(sqlResult, sqlResults, createNode)
+      );
 
-  return new Promise((fulfill, reject) => {
-    dbConnection.query(query, (error, results, fields) => {
-      if (error) return reject(error);
-
-      if (Array.isArray(results)) {
-        results.forEach((result, index) => {
-          const sanitizedResult = Object.assign({}, result, {
-            id: result[idFieldName]
-          });
-          const resultNode = MySqlNode(sanitizedResult);
-          createNode(resultNode);
-        });
-      }
-
-      fulfill();
-    });
-
-    dbConnection.end();
-  });
+    db.end();
+  } catch (e) {
+    console.error(e);
+    db.end();
+  }
 };

package.json

@@ -1,8 +1,13 @@
 {
   "name": "gatsby-source-mysql",
-  "version": "1.0.0",
+  "version": "2.0.0",
   "description": "Source plugin for pulling data into Gatsby from MySQL database.",
   "author": "Malcolm Kee <[email protected]>",
+  "scripts": {
+    "test": "jest",
+    "test:watch": "jest --watch",
+    "lint": "eslint src"
+  },
   "keywords": [
     "gatsby",
     "gatsby-plugin",
@@ -11,7 +16,8 @@
   "license": "MIT",
   "dependencies": {
     "gatsby-node-helpers": "^0.3.0",
-    "mysql": "^2.16.0"
+    "mysql": "^2.16.0",
+    "pluralize": "^7.0.0"
   },
   "peerDependencies": {
     "gatsby": ">2.0.0"
@@ -21,5 +27,10 @@
   "homepage": "https://github.com/malcolm-kee/gatsby-source-mysql#readme",
   "bugs": {
     "url": "https://github.com/malcolm-kee/gatsby-source-mysql/issues"
+  },
+  "devDependencies": {
+    "@types/jest": "^24.0.12",
+    "eslint": "^5.16.0",
+    "jest": "^24.8.0"
   }
 }