fixed limit/offset for sqlite,mysql and cubrid

tests for this are on elasticsearch branch (due to huge refactoring
there) and will come later by merge

framework/yii/db/cubrid/QueryBuilder.php

@@ -67,4 +67,24 @@ class QueryBuilder extends \yii\db\QueryBuilder
 			throw new InvalidParamException("There is not sequence associated with table '$tableName'.");
 		}
 	}
+
+	/**
+	 * @inheritDocs
+	 */
+	public function buildLimit($limit, $offset)
+	{
+		$sql = '';
+		// limit is not optional in CUBRID
+		// http://www.cubrid.org/manual/90/en/LIMIT%20Clause
+		// "You can specify a very big integer for row_count to display to the last row, starting from a specific row."
+		if ($limit !== null && $limit >= 0) {
+			$sql = 'LIMIT ' . (int)$limit;
+			if ($offset > 0) {
+				$sql .= ' OFFSET ' . (int)$offset;
+			}
+		} elseif ($offset > 0) {
+			$sql = 'LIMIT ' . (int)$offset . ', 18446744073709551615'; // 2^64-1
+		}
+		return $sql;
+	}
 }

framework/yii/db/mysql/QueryBuilder.php

@@ -140,4 +140,24 @@ class QueryBuilder extends \yii\db\QueryBuilder
 	{
 		return 'SET FOREIGN_KEY_CHECKS = ' . ($check ? 1 : 0);
 	}
+
+	/**
+	 * @inheritDocs
+	 */
+	public function buildLimit($limit, $offset)
+	{
+		$sql = '';
+		// limit is not optional in MySQL
+		// http://stackoverflow.com/a/271650/1106908
+		// http://dev.mysql.com/doc/refman/5.0/en/select.html#idm47619502796240
+		if ($limit !== null && $limit >= 0) {
+			$sql = 'LIMIT ' . (int)$limit;
+			if ($offset > 0) {
+				$sql .= ' OFFSET ' . (int)$offset;
+			}
+		} elseif ($offset > 0) {
+			$sql = 'LIMIT ' . (int)$offset . ', 18446744073709551615'; // 2^64-1
+		}
+		return $sql;
+	}
 }

framework/yii/db/sqlite/QueryBuilder.php

@@ -206,4 +206,23 @@ class QueryBuilder extends \yii\db\QueryBuilder
 	{
 		throw new NotSupportedException(__METHOD__ . ' is not supported by SQLite.');
 	}
+
+	/**
+	 * @inheritDocs
+	 */
+	public function buildLimit($limit, $offset)
+	{
+		$sql = '';
+		// limit is not optional in SQLite
+		// http://www.sqlite.org/syntaxdiagrams.html#select-stmt
+		if ($limit !== null && $limit >= 0) {
+			$sql = 'LIMIT ' . (int)$limit;
+			if ($offset > 0) {
+				$sql .= ' OFFSET ' . (int)$offset;
+			}
+		} elseif ($offset > 0) {
+			$sql = 'LIMIT 9223372036854775807 OFFSET ' . (int)$offset; // 2^63-1
+		}
+		return $sql;
+	}
 }