new "expression" clause and object aliases added

Author: artzhookov

lib/dialects/base/blocks.js

@@ -128,12 +128,36 @@ module.exports = function(dialect) {
 		return this.dialect._wrapIdentifier(params.table);
 	});
 
+	dialect.blocks.add('expression', function(params) {
+		return params.expression;
+	});
+
 	dialect.blocks.add('name', function(params) {
 		return this.dialect._wrapIdentifier(params.name);
 	});
 
 	dialect.blocks.add('alias', function(params) {
-		return 'as ' + this.dialect._wrapIdentifier(params.alias);
+		var self = this;
+
+		var result;
+
+		if (_.isObject(params.alias)) {
+			if (!params.alias.name) {
+				throw new Error('Alias `name` property is required');
+			}
+
+			result = this.dialect._wrapIdentifier(params.alias.name);
+
+			if (_.isArray(params.alias.columns)) {
+				result += '(' + _(params.alias.columns).map(function(column) {
+					return self.dialect._wrapIdentifier(column);
+				}).join(', ') + ')';
+			}
+		} else {
+			result = this.dialect._wrapIdentifier(params.alias);
+		}
+
+		return 'as ' + result;
 	});
 
 	dialect.blocks.add('condition', function(params) {

lib/dialects/base/templates.js

@@ -3,7 +3,7 @@
 var _ = require('underscore');
 
 module.exports = function(dialect) {
-	var availableSourceProps = ['table', 'query', 'select'];
+	var availableSourceProps = ['table', 'query', 'select', 'expression'];
 	var availableJoinTypes = ['natural', 'cross', 'inner', 'outer', 'left', 'right', 'full', 'self'];
 	var orRegExp = /^(rollback|abort|replace|fail|ignore)$/i;
 
@@ -52,7 +52,7 @@ module.exports = function(dialect) {
 
 
 	dialect.templates.add('joinItem', {
-		pattern: '{type} join {table} {query} {select} {alias} {on}',
+		pattern: '{type} join {table} {query} {select} {expression} {alias} {on}',
 		validate: function(type, params) {
 			hasOneOfProps('join', params, availableSourceProps);
 
@@ -69,16 +69,16 @@ module.exports = function(dialect) {
 
 
 	dialect.templates.add('withItem', {
-		pattern: '{name} {fields} as {query} {select}',
+		pattern: '{name} {fields} as {query} {select} {expression}',
 		validate: function(type, params) {
 			hasRequiredProp('with', params, 'name');
-			hasOneOfProps('with', params, ['query', 'select']);
+			hasOneOfProps('with', params, ['query', 'select', 'expression']);
 		}
 	});
 
 
 	dialect.templates.add('fromItem', {
-		pattern: '{table} {query} {select}',
+		pattern: '{table} {query} {select} {expression}',
 		validate: function(type, params) {
 			hasOneOfProps('from', params, availableSourceProps);
 		}
@@ -89,7 +89,7 @@ module.exports = function(dialect) {
 
 	dialect.templates.add('select', {
 		pattern: '{with} select {distinct} {fields} ' +
-			'from {from} {table} {query} {select} {alias} ' +
+			'from {from} {table} {query} {select} {expression} {alias} ' +
 			'{join} {condition} {group} {sort} {limit} {offset}',
 		defaults: {
 			fields: {}

tests/0_base.js

@@ -37,8 +37,8 @@ describe('Builder', function() {
 			jsonSql.build({});
 		}).to.throwError(function(e) {
 			expect(e).to.be.a(Error);
-			expect(e.message).to.be('Neither `table`, `query`, `select` properties are not set in ' +
-				'`select` clause');
+			expect(e.message).to.be('Neither `table`, `query`, `select`, `expression` properties ' +
+				'are not set in `select` clause');
 		});
 	});
 
@@ -104,7 +104,8 @@ describe('Builder', function() {
 			});
 		}).to.throwError(function(e) {
 			expect(e).to.be.a(Error);
-			expect(e.message).to.be('Neither `query`, `select` properties are not set in `with` clause');
+			expect(e.message).to.be('Neither `query`, `select`, `expression` properties ' +
+				'are not set in `with` clause');
 		});
 	});
 

tests/1_select.js

@@ -203,7 +203,7 @@ describe('Select', function() {
 	});
 
 	describe('alias', function() {
-		it('should be ok with `alias` property', function() {
+		it('should be ok with string `alias` property', function() {
 			var result = jsonSql.build({
 				table: 'users',
 				alias: 'u'
@@ -212,6 +212,57 @@ describe('Select', function() {
 			expect(result.query).to.be('select * from "users" as "u";');
 			expect(result.values).to.eql({});
 		});
+
+		it('should throw error if object `alias` does not have `name` property', function() {
+			expect(function() {
+				jsonSql.build({
+					table: 'users',
+					alias: {}
+				});
+			}).to.throwError(function(e) {
+				expect(e).to.be.an(Error);
+				expect(e.message).to.be('Alias `name` property is required');
+			});
+		});
+
+		it('should be ok with object `alias`(`name`) property', function() {
+			var result = jsonSql.build({
+				table: 'users',
+				alias: {
+					name: 'u'
+				}
+			});
+
+			expect(result.query).to.be('select * from "users" as "u";');
+			expect(result.values).to.eql({});
+		});
+
+		it('should be ok with object `alias`(`name`, `columns`) property', function() {
+			var result = jsonSql.build({
+				table: 'users',
+				alias: {
+					name: 'u',
+					columns: ['a', 'b']
+				}
+			});
+
+			expect(result.query).to.be('select * from "users" as "u"("a", "b");');
+			expect(result.values).to.eql({});
+		});
+	});
+
+	describe('query', function() {
+		it('should be ok with `query` property', function() {
+			var result = jsonSql.build({
+				query: {
+					type: 'select',
+					table: 't'
+				}
+			});
+
+			expect(result.query).to.be('select * from (select * from "t");');
+			expect(result.values).to.eql({});
+		});
 	});
 
 	describe('select', function() {
@@ -227,6 +278,17 @@ describe('Select', function() {
 		});
 	});
 
+	describe('expression', function() {
+		it('should be ok with `expression` property', function() {
+			var result = jsonSql.build({
+				expression: 'function()'
+			});
+
+			expect(result.query).to.be('select * from function();');
+			expect(result.values).to.eql({});
+		});
+	});
+
 	describe('join', function() {
 		it('should throw error without `table`, `query` and `select` properties',
 			function() {
@@ -237,8 +299,8 @@ describe('Select', function() {
 					});
 				}).to.throwError(function(e) {
 					expect(e).to.be.a(Error);
-					expect(e.message).to.be('Neither `table`, `query`, `select` properties are not set in ' +
-						'`join` clause');
+					expect(e.message).to.be('Neither `table`, `query`, `select`, `expression` properties ' +
+						'are not set in `join` clause');
 				});
 			}
 		);