Added alternate query handler hooks for TDS---mostly pertaining to LI…

…MIT and OFFSET.

lib/Dialects/mysql.js

@@ -1,5 +1,7 @@
 var util = require("util");
 
+exports.name = 'mysql';
+
 exports.escapeId = function () {
 	return Array.prototype.slice.apply(arguments).map(function (el) {
 		if (typeof el == "object") {

lib/Dialects/postgresql.js

@@ -1,5 +1,7 @@
 var util = require("util");
 
+exports.name = 'postgresql';
+
 exports.escapeId = function () {
 	return Array.prototype.slice.apply(arguments).map(function (el) {
 		if (typeof el == "object") {

lib/Dialects/sqlite.js

@@ -1,5 +1,6 @@
 var util = require("util");
 
+exports.name = 'sqlite';
 exports.escapeId = require("./mysql").escapeId;
 
 exports.escapeVal = function (val, timeZone) {

lib/Dialects/tds.js

@@ -1,5 +1,7 @@
 var util = require("util");
 
+exports.name = 'tds';
+
 exports.escapeId = function () {
 	return Array.prototype.slice.apply(arguments).map(function (el) {
 		if (typeof el == "object") {

lib/Remove.js

@@ -5,7 +5,9 @@ exports.RemoveQuery = RemoveQuery;
 function RemoveQuery(Dialect) {
 	var sql = {
 		where : [],
-		order : []
+		order : [],
+		use_top: (Dialect.name === 'tds'),
+		can_use_order_by: (Dialect.name !== 'tds')
 	};
 
 	return {
@@ -25,7 +27,14 @@ function RemoveQuery(Dialect) {
 		build: function () {
 			var query = [], tmp;
 
-			query.push("DELETE FROM");
+			query.push("DELETE");
+
+			// TDS only!
+			if (sql.use_top && sql.hasOwnProperty("limit")) {
+				query.push("TOP (" + sql.limit + ")");
+			}
+
+			query.push("FROM");
 			query.push(Dialect.escapeId(sql.table));
 
 			query = query.concat(Where.build(Dialect, sql.where));
@@ -41,20 +50,22 @@ function RemoveQuery(Dialect) {
 					}
 				}
 
-				if (tmp.length > 0) {
+				if (tmp.length > 0 && sql.can_use_order_by) {
 					query.push("ORDER BY " + tmp.join(", "));
 				}
 			}
 
 			// limit
-			if (sql.hasOwnProperty("limit")) {
-				if (sql.hasOwnProperty("offset")) {
-					query.push("LIMIT " + sql.limit + " OFFSET " + sql.offset);
-				} else {
-					query.push("LIMIT " + sql.limit);
+			if (!sql.use_top) {
+				if (sql.hasOwnProperty("limit")) {
+					if (sql.hasOwnProperty("offset")) {
+						query.push("LIMIT " + sql.limit + " OFFSET " + sql.offset);
+					} else {
+						query.push("LIMIT " + sql.limit);
+					}
+				} else if (sql.hasOwnProperty("offset")) {
+					query.push("OFFSET " + sql.offset);
 				}
-			} else if (sql.hasOwnProperty("offset")) {
-				query.push("OFFSET " + sql.offset);
 			}
 
 			return query.join(" ");

lib/Select.js

@@ -17,7 +17,9 @@ function SelectQuery(Dialect) {
 		order        : [],
 		group_by     : null,
 		found_rows   : false,
-		where_exists : false
+		where_exists : false,
+		use_top      : (Dialect.name === 'tds'),
+		manual_offset : (Dialect.name === 'tds')
 	};
 	var get_table_alias = function (table) {
 		for (var i = 0; i < sql.from.length; i++) {
@@ -194,8 +196,44 @@ function SelectQuery(Dialect) {
 				this.fun(fun_stack.pop());
 			}
 
+			// Calculate ORDER BY early, in case we need it for
+			// manual offset.
+			//
+			if (sql.group_by) {
+				sql.group_by.forEach(function (column) {
+					if (column[0] == "-") {
+						sql.order.unshift({ c: column.substr(1), d: "DESC" });
+					}
+				});
+			}
+
+			order_by = []; 
+
+			if (sql.order.length > 0) {
+				for (i = 0; i < sql.order.length; i++) {
+					if (Array.isArray(sql.order[i].c)) {
+						order_by.push(Dialect.escapeId.apply(Dialect, sql.order[i].c) + " " + sql.order[i].d);
+					} else {
+						order_by.push(Dialect.escapeId(sql.order[i].c) + " " + sql.order[i].d);
+					}
+				}
+			}
+
+			// TDS only - Manual Offset Workaround
+			if (sql.manual_offset && sql.hasOwnProperty("offset")) {
+				if (sql.use_top && sql.hasOwnProperty("limit"))
+					query.push("SELECT TOP " + sql.limit + " * FROM (");
+				else
+					query.push("SELECT * FROM (");
+			}
+
 			query.push("SELECT");
 
+			// TDS only - TOP instead of LIMIT
+			if (sql.use_top && sql.hasOwnProperty("limit") && !sql.hasOwnProperty("offset")) {
+				query.push("TOP " + sql.limit);
+			}
+
 			for (i = 0; i < sql.from.length; i++) {
 				sql.from[i].a = "t" + (i + 1);
 			}
@@ -288,8 +326,23 @@ function SelectQuery(Dialect) {
 				query.push("SQL_CALC_FOUND_ROWS");
 			}
 
+			// Need to allow for TDS' manual offset, if necessary. Otherwise,
+			// we can just proceed with an unaltered SELECT stanza.
+			//
+			var row_number_clause;
+
+			if (sql.manual_offset && sql.hasOwnProperty('offset')) {
+				row_number_clause = order_by.length > 0 ? order_by.join(", ") : "id ASC";
+			}
+
 			if (tmp.length) {
+				if (sql.manual_offset && sql.hasOwnProperty('offset')) {
+					tmp.unshift("ROW_NUMBER() OVER (ORDER BY " + row_number_clause + ") AS p_RN")
+				}
+
 				query.push(tmp.join(", "));
+			} else if (sql.manual_offset && sql.hasOwnProperty('offset')) {
+				query.push("ROW_NUMBER() OVER (ORDER BY " + row_number_clause + ") AS p_RN, *");
 			} else {
 				query.push("*");
 			}
@@ -349,31 +402,27 @@ function SelectQuery(Dialect) {
 				}).join(", "));
 			}
 
-			// order
-			if (sql.order.length > 0) {
-				tmp = [];
-				for (i = 0; i < sql.order.length; i++) {
-					if (Array.isArray(sql.order[i].c)) {
-						tmp.push(Dialect.escapeId.apply(Dialect, sql.order[i].c) + " " + sql.order[i].d);
-					} else {
-						tmp.push(Dialect.escapeId(sql.order[i].c) + " " + sql.order[i].d);
-					}
-				}
+			// TDS only - Manual Offset Workaround
+			if (sql.manual_offset && sql.hasOwnProperty("offset")) {
+				query.push(") SQ WHERE p_RN > " + sql.offset);
+			}
 
-				if (tmp.length > 0) {
-					query.push("ORDER BY " + tmp.join(", "));
-				}
+			// order
+			if (order_by.length > 0) {
+				query.push("ORDER BY " + order_by.join(", "));
 			}
 
-			// limit
-			if (sql.hasOwnProperty("limit")) {
-				if (sql.hasOwnProperty("offset")) {
-					query.push("LIMIT " + sql.limit + " OFFSET " + sql.offset);
-				} else {
-					query.push("LIMIT " + sql.limit);
+			// limit (non-TDS only!)
+			if (!sql.use_top) {
+				if (sql.hasOwnProperty("limit")) {
+					if (!sql.manual_offset && sql.hasOwnProperty("offset")) {
+						query.push("LIMIT " + sql.limit + " OFFSET " + sql.offset);
+					} else {
+						query.push("LIMIT " + sql.limit);
+					}
+				} else if (!sql.manual_offset && sql.hasOwnProperty("offset")) {
+					query.push("OFFSET " + sql.offset);
 				}
-			} else if (sql.hasOwnProperty("offset")) {
-				query.push("OFFSET " + sql.offset);
 			}
 
 			return query.join(" ");

lib/Where.js

@@ -154,7 +154,11 @@ function buildOrGroup(Dialect, where) {
 			if (Array.isArray(where.w[k])) {
 				if (where.w[k].length === 0) {
 					// #274: IN with empty arrays should be a false sentence
-					query.push("FALSE");
+					//
+					// "1=0" will still evaluate to false and plays nice with
+					// TDS.
+					//
+					query.push("1=0");
 				} else {
 					query.push(buildComparisonKey(Dialect, where.t, k) + " IN " + Dialect.escapeVal(where.w[k]));
 				}

test/common.js

@@ -4,26 +4,26 @@ var Query  = require('../');
 common.Query = Query;
 common.Text  = Query.Text;
 
-common.Select = function () {
-	var q = new (Query.Query)();
+common.Select = function (dialect) {
+	var q = new (Query.Query)(dialect);
 
 	return q.select();
 };
 
-common.Insert = function () {
-	var q = new (Query.Query)();
+common.Insert = function (dialect) {
+	var q = new (Query.Query)(dialect);
 
 	return q.insert();
 };
 
-common.Update = function () {
-	var q = new (Query.Query)();
+common.Update = function (dialect) {
+	var q = new (Query.Query)(dialect);
 
 	return q.update();
 };
 
-common.Remove = function () {
-	var q = new (Query.Query)();
+common.Remove = function (dialect) {
+	var q = new (Query.Query)(dialect);
 
 	return q.remove();
 };

test/integration/test-limit-offset-tds.js

@@ -0,0 +1,7 @@
+var common     = require('../common');
+var assert     = require('assert');
+
+assert.equal(
+	common.Select('tds').from('table1').offset('123').limit('456').build(),
+	"SELECT TOP 456 * FROM ( SELECT ROW_NUMBER() OVER (ORDER BY id ASC) AS p_RN, * FROM [table1] ) SQ WHERE p_RN > 123"
+);

test/integration/test-limit.js

@@ -6,7 +6,17 @@ assert.equal(
 	"SELECT * FROM `table1` LIMIT 123"
 );
 
+assert.equal(
+	common.Select('tds').from('table1').limit(123).build(),
+	"SELECT TOP 123 * FROM [table1]"
+);
+
 assert.equal(
 	common.Select().from('table1').limit('123456789').build(),
 	"SELECT * FROM `table1` LIMIT 123456789"
 );
+
+assert.equal(
+	common.Select('tds').from('table1').limit('123456789').build(),
+	"SELECT TOP 123456789 * FROM [table1]"
+);

test/integration/test-offset.js

@@ -6,7 +6,17 @@ assert.equal(
 	"SELECT * FROM `table1` OFFSET 3"
 );
 
+assert.equal(
+	common.Select('tds').from('table1').offset(3).build(),
+	"SELECT * FROM ( SELECT ROW_NUMBER() OVER (ORDER BY id ASC) AS p_RN, * FROM [table1] ) SQ WHERE p_RN > 3"
+);
+
 assert.equal(
 	common.Select().from('table1').offset('123456789').build(),
 	"SELECT * FROM `table1` OFFSET 123456789"
 );
+
+assert.equal(
+	common.Select('tds').from('table1').offset('123456789').build(),
+	"SELECT * FROM ( SELECT ROW_NUMBER() OVER (ORDER BY id ASC) AS p_RN, * FROM [table1] ) SQ WHERE p_RN > 123456789"
+);

test/integration/test-remove.js

@@ -26,17 +26,37 @@ assert.equal(
 	"DELETE FROM `table1` LIMIT 10"
 );
 
+assert.equal(
+	common.Remove('tds').from('table1').limit(10).build(),
+	"DELETE TOP (10) FROM [table1]"
+);
+
 assert.equal(
 	common.Remove().from('table1').limit(10).offset(3).build(),
 	"DELETE FROM `table1` LIMIT 10 OFFSET 3"
 );
 
+assert.equal(
+	common.Remove('tds').from('table1').limit(10).offset(3).build(),
+	"DELETE TOP (10) FROM [table1]"
+);
+
 assert.equal(
 	common.Remove().from('table1').order('col').limit(5).build(),
 	"DELETE FROM `table1` ORDER BY `col` ASC LIMIT 5"
 );
 
+assert.equal(
+	common.Remove('tds').from('table1').order('col').limit(5).build(),
+	"DELETE TOP (5) FROM [table1]"
+);
+
 assert.equal(
 	common.Remove().from('table1').order('col1', 'A').order('col2', 'Z').limit(5).build(),
 	"DELETE FROM `table1` ORDER BY `col1` ASC, `col2` DESC LIMIT 5"
 );
+
+assert.equal(
+	common.Remove('tds').from('table1').order('col1', 'A').order('col2', 'Z').limit(5).build(),
+	"DELETE TOP (5) FROM [table1]"
+);

test/integration/test-where.js

@@ -73,7 +73,7 @@ assert.equal(
 
 assert.equal(
 	common.Select().from('table1').where({ col: [] }).build(),
-	"SELECT * FROM `table1` WHERE FALSE"
+	"SELECT * FROM `table1` WHERE 1=0"
 );
 
 assert.equal(