Foreign Key

lib/column.js

@@ -8,6 +8,7 @@ Column.iface = [
   'getDataType',
   'getMaxLength',
   'isPrimaryKey',
+  'isForeignKey',
   'getDefaultValue',
   'isUnique',
   'isAutoIncrementing'

lib/mysql/column.js

@@ -29,6 +29,10 @@ Column.prototype.isPrimaryKey = function () {
   return this.meta.column_key === 'PRI';
 };
 
+Column.prototype.isForeignKey = function () {
+  return this.meta.foreign_key === true;
+};
+
 Column.prototype.getDefaultValue = function () {
   return this.meta.column_default;
 };

lib/mysql/driver.js

@@ -2,10 +2,18 @@ var mysql = require('mysql');
 var Table = require('../table');
 var Column = require('./column');
 var Index = require('./index');
+var metaUtils = require('../util');
+var arrayContains = metaUtils.arrayContains;
 
 exports.connect = function (options, callback) {
   try {
-    var client = mysql.createClient(options);
+    var client;
+    if (typeof(mysql.createConnection) === 'undefined') {
+      client =  new mysql.createClient(options);
+    } else {
+      client =  new mysql.createConnection(options);
+    }
+
     callback(null, new Driver(client));
   } catch (err) {
     callback(err);
@@ -39,9 +47,37 @@ Driver.prototype.getTables = function (callback) {
 };
 
 Driver.prototype.getColumns = function (tableName, callback) {
-  var handler = handleResults.bind(this, Column, callback);
+  var handler = handleResults.bind(this, Column, findForeignKeys.bind(this));
   var db = getClientDatabase(this.client);
   this.client.query("select * from information_schema.columns where table_schema = ? and table_name = ?", [db, tableName], handler);
+
+  function findForeignKeys(err, columns) {
+    if(err) {
+      return callback(err);
+    }
+
+    this.client.query("select * from information_schema.key_column_usage " +
+      "WHERE table_schema = ? AND table_name = ? AND referenced_column_name IS NOT NULL",
+      [db, tableName], onForeignKeysResult.bind(this, columns, this.client));
+  }
+
+  function onForeignKeysResult(columns, client, err, result) {
+    if(err) {
+      return callback(err);
+    }
+
+    var foreignKeys = result.map(function (row) {
+      return row.COLUMN_NAME;
+    });
+
+    columns.forEach(function (column) {
+      if (arrayContains(foreignKeys, column.getName())) {
+        column.meta.foreign_key = true;
+      }
+    });
+
+    callback(null, columns);
+  }
 };
 
 Driver.prototype.getIndexes = function(tableName, callback) {

lib/pg/column.js

@@ -29,6 +29,10 @@ Column.prototype.isPrimaryKey = function () {
   return this.meta.primary_key === true;
 };
 
+Column.prototype.isForeignKey = function () {
+  return this.meta.foreign_key === true;
+};
+
 Column.prototype.getDefaultValue = function () {
   return this.meta.column_default;
 };

lib/pg/driver.js

@@ -2,6 +2,7 @@ var pg = require('pg');
 var Table = require('../table');
 var Column = require('./column');
 var Index = require('./index');
+var arrayContains = require('../util').arrayContains;
 
 exports.connect = function (options, callback) {
   var client = new pg.Client(options);
@@ -12,7 +13,6 @@ exports.connect = function (options, callback) {
 };
 
 exports.connectToExistingConnection = function(client, callback){
-  // console.log("connecting to existing connection");
   callback(null, new Driver(client));
 };
 
@@ -105,10 +105,45 @@ Driver.prototype.getColumns = function (tableName, callback) {
         column.meta.unique = true;
       }
     });
+    findForeignKeys(null, columns, client);
+  }
+
+  function findForeignKeys(err, columns, client) {
+    if(err) {
+      return callback(err);
+    }
+
+    client.query("select cu.column_name " +
+      "from information_schema.key_column_usage cu, " +
+      "information_schema.table_constraints tc " +
+      "where tc.table_name = cu.table_name " +
+      "and tc.constraint_type = 'FOREIGN KEY' " +
+      "and tc.constraint_name = cu.constraint_name " +
+      "and tc.table_name = $1",
+      [tableName],
+      onForeignKeysResult.bind(this, columns, client)
+    );
+  }
+
+  function onForeignKeysResult(columns, client, err, result) {
+    if(err) {
+      return callbacke(err);
+    }
+
+    var foreignKeys = result.rows.map(function (row) {
+      return row.column_name;
+    });
+
+    columns.forEach(function (column) {
+      if (arrayContains(foreignKeys, column.getName())) {
+        column.meta.foreign_key = true;
+      }
+    });
+
     checkAutoincrement(null, columns, client);
   }
 
-function checkAutoincrement(err, columns, client) {
+  function checkAutoincrement(err, columns, client) {
     if (err) {
       return callback(err);
     }
@@ -135,6 +170,7 @@ function checkAutoincrement(err, columns, client) {
         column.meta.autoincrement = true;
       }
     });
+
     callback(null, columns);
   }
 };
@@ -171,12 +207,3 @@ function handleResults(obj, callback, err, result) {
 
   callback(null, objects);
 }
-
-function arrayContains(arr, item) {
-  for (var i = 0; i < arr.length; i++) {
-    if (arr[i] === item) {
-      return true;
-    }
-  }
-  return false;
-}

lib/sqlite3/column.js

@@ -19,10 +19,10 @@ Column.prototype.isNullable = function () {
 
 Column.prototype.getMaxLength = function () {
   var match = this.getDataType().match(/\((\d+)\)$/);
-  if (match[1]) {
+  if (match && match[1]) {
     return parseInt(match[1]);
   }
-  return -1;
+  return null;
 };
 
 Column.prototype.getDataType = function() {
@@ -33,6 +33,10 @@ Column.prototype.isPrimaryKey = function () {
   return this.meta.pk === 1;
 };
 
+Column.prototype.isForeignKey = function () {
+  return this.meta.fk === 1;
+};
+
 Column.prototype.getDefaultValue = function () {
   return this.meta.dflt_value;
 };

lib/sqlite3/driver.js

@@ -2,6 +2,7 @@ var sqlite3 = require('sqlite3');
 var Table = require('../table');
 var Column = require('./column');
 var Index = require('./index');
+var arrayContains = require('../util').arrayContains;
 
 exports.connect = function (options, callback) {
   try {
@@ -71,7 +72,31 @@ Driver.prototype.getColumns = function (tableName, callback) {
       }
       colNumber++;
     });
-    callback(err,previous);
+
+    findForeignKeys(previous, this.client);
+  }
+
+  function findForeignKeys(columns, client) {
+    client.all('PRAGMA foreign_key_list(' + tableName  + ');',
+      onForeignKeysResult.bind(this, columns, client));
+  }
+
+  function onForeignKeysResult(columns, client, err, result) {
+    if(err) {
+      return callback(err);
+    }
+
+    var foreignKeys = result.map(function (row) {
+      return row.from;
+    });
+
+    columns.forEach(function (column) {
+      if (arrayContains(foreignKeys, column.getName())) {
+        column.meta.fk = 1;
+      }
+    });
+
+    callback(err, columns);
   }
 
 };

lib/util.js

@@ -4,4 +4,13 @@ exports.lowercaseKeys = function (obj) {
     newObj[key.toLowerCase()] = obj[key];
   });
   return newObj;
-};
+};
+
+exports.arrayContains = function(arr, item) {
+  for (var i = 0; i < arr.length; i++) {
+    if (arr[i] === item) {
+      return true;
+    }
+  }
+  return false;
+}

test/mysql/column-test.js

@@ -2,7 +2,7 @@ var expect = require('chai').expect;
 var Column = require('../../lib/mysql/column');
 var iface = require('../../lib/column').iface;
 
-describe('pg column', function () {
+describe('mysql column', function () {
   it('should implement all the methods defined in the base column interface', function (done) {
     var c = new Column({ column_name: 'col', data_type: 'integer' });
     iface.forEach(function (method) {
@@ -52,6 +52,14 @@ describe('pg column', function () {
     expect(c.isPrimaryKey()).to.be.false;
     done();
   });
+
+  it('should implement the isForeignKey method', function(done) {
+    var c = new Column({ column_name: 'col', foreign_key: true });
+    expect(c.isForeignKey()).to.be.true;
+    var c = new Column({ column_name: 'col', foreign_key: false });
+    expect(c.isForeignKey()).to.be.false;
+    done();
+  });
 
   it('should implement the getDefaultValue method', function(done) {
     var c = new Column({ column_name: 'col', column_default: '30' });

test/mysql/driver-test.js

@@ -8,11 +8,19 @@ describe('mysql driver', function() {
     mysql.connect({ database: 'db_meta_test' }, onConnect);
 
     function onConnect(err, dbDriver) {
+      if(err) {
+        return done(err);
+      }
+
       driver = dbDriver;
-      driver.client.query('CREATE TABLE person (id INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL, name VARCHAR(255) NOT NULL, email VARCHAR(100) UNIQUE, age INTEGER DEFAULT 30);', createIndex);
+      driver.client.query('CREATE TABLE person (id INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL, name VARCHAR(255) NOT NULL, email VARCHAR(100) UNIQUE, age INTEGER DEFAULT 30, ref INTEGER, CONSTRAINT FOREIGN KEY (ref) REFERENCES person(id));', createIndex);
     }
 
     function createIndex(err) {
+      if(err) {
+        return done(err);
+      }
+
       driver.client.query('CREATE INDEX person_name_idx ON person (name, age)', done);
     }
   });
@@ -50,7 +58,7 @@ describe('mysql driver', function() {
     function onResult(err, columns) {
       expect(err).to.be.null;
       expect(columns).not.to.be.empty;
-      expect(columns.length).to.equal(4);
+      expect(columns.length).to.equal(5);
 
       var idColumn = getColumnByName(columns, 'id');
       expect(idColumn).not.to.be.null;
@@ -59,6 +67,7 @@ describe('mysql driver', function() {
       expect(idColumn.getMaxLength()).to.be.null;
       expect(idColumn.getDataType()).to.equal('INT');
       expect(idColumn.isPrimaryKey()).to.be.true;
+      expect(idColumn.isForeignKey()).to.be.false;
       expect(idColumn.isUnique()).to.be.true;
       expect(idColumn.isAutoIncrementing()).to.be.true;
 
@@ -87,6 +96,15 @@ describe('mysql driver', function() {
       expect(ageColumn.isUnique()).to.be.false;
       expect(ageColumn.isAutoIncrementing()).to.be.false;
 
+      var refColumn = getColumnByName(columns, 'ref');
+      expect(refColumn).to.be.not.null;
+      expect(refColumn.meta).not.to.be.empty;
+      expect(refColumn.isForeignKey(), 'FK').to.be.true;
+      expect(refColumn.isPrimaryKey()).to.be.false;
+      expect(refColumn.getDataType()).to.equal('INT');
+      expect(refColumn.getMaxLength()).to.be.null;
+      expect(refColumn.isAutoIncrementing()).to.be.false;
+
       done();
     }
   });
@@ -95,19 +113,19 @@ describe('mysql driver', function() {
     driver.getIndexes('person', onResult);
 
     function onResult(err, indexes) {
-      expect(indexes.length).to.equal(4);
+      expect(indexes.length).to.equal(5);
       expect(indexes[0].getName()).to.equal('PRIMARY');
       expect(indexes[0].getTableName()).to.equal('person');
       expect(indexes[0].getColumnName()).to.equal('id');
       expect(indexes[1].getName()).to.equal('email');
       expect(indexes[1].getTableName()).to.equal('person');
       expect(indexes[1].getColumnName()).to.equal('email');
-      expect(indexes[2].getName()).to.equal('person_name_idx');
-      expect(indexes[2].getTableName()).to.equal('person');
-      expect(indexes[2].getColumnName()).to.equal('name');
       expect(indexes[3].getName()).to.equal('person_name_idx');
       expect(indexes[3].getTableName()).to.equal('person');
-      expect(indexes[3].getColumnName()).to.equal('age');
+      expect(indexes[3].getColumnName()).to.equal('name');
+      expect(indexes[4].getName()).to.equal('person_name_idx');
+      expect(indexes[4].getTableName()).to.equal('person');
+      expect(indexes[4].getColumnName()).to.equal('age');
       done();
     }
   });

test/pg/column-test.js

@@ -53,6 +53,14 @@ describe('pg column', function () {
     done();
   });
 
+  it('should implement the isForeignKey method', function(done) {
+    var c = new Column({ column_name: 'col', foreign_key: true });
+    expect(c.isForeignKey()).to.be.true;
+    c = new Column({ column_name: 'col', foreign_key: false });
+    expect(c.isForeignKey()).to.be.false;
+    done();
+  });
+
   it('should implement the getDefaultValue method', function(done) {
     var c = new Column({ column_name: 'col', column_default: '30' });
     expect(c.getDefaultValue()).to.equal('30');