diff --git a/common/framework/parsers/dbquery/column.php b/common/framework/parsers/dbquery/columnread.php
similarity index 80%
rename from common/framework/parsers/dbquery/column.php
rename to common/framework/parsers/dbquery/columnread.php
index c6eaea342..1b51a8121 100644
--- a/common/framework/parsers/dbquery/column.php
+++ b/common/framework/parsers/dbquery/columnread.php
@@ -3,9 +3,9 @@
 namespace Rhymix\Framework\Parsers\DBQuery;
 
 /**
- * Column class.
+ * ColumnRead class.
  */
-class Column
+class ColumnRead
 {
 	public $name;
 	public $alias;
diff --git a/common/framework/parsers/dbquery/columnwrite.php b/common/framework/parsers/dbquery/columnwrite.php
new file mode 100644
index 000000000..49c2efc88
--- /dev/null
+++ b/common/framework/parsers/dbquery/columnwrite.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Rhymix\Framework\Parsers\DBQuery;
+
+/**
+ * ColumnWrite class.
+ */
+class ColumnWrite extends VariableBase
+{
+	public $name;
+	public $operation = 'equal';
+	public $var;
+	public $default;
+	public $not_null;
+	public $filter;
+	public $minlength = 0;
+	public $maxlength = 0;
+}
diff --git a/common/framework/parsers/dbquery/query.php b/common/framework/parsers/dbquery/query.php
index 518509695..7aa8ec968 100644
--- a/common/framework/parsers/dbquery/query.php
+++ b/common/framework/parsers/dbquery/query.php
@@ -13,6 +13,8 @@ class Query extends VariableBase
 	public $operation;
 	public $column;
 	public $pipe;
+	public $join_type;
+	public $join_conditions = array();
 	public $tables = array();
 	public $columns = array();
 	public $conditions = array();
@@ -50,6 +52,15 @@ class Query extends VariableBase
 			case 'SELECT':
 				$result = $this->_getSelectQueryString($count_only);
 				break;
+			case 'INSERT':
+				$result = $this->_getInsertQueryString();
+				break;
+			case 'UPDATE':
+				$result = $this->_getUpdateQueryString();
+				break;
+			case 'DELETE':
+				$result = $this->_getDeleteQueryString();
+				break;
 			default:
 				$result = '';
 		}
@@ -119,38 +130,15 @@ class Query extends VariableBase
 			$result .= implode(', ', $columns);
 		}
 		
-		// Compose the table list.
-		$tables = array();
-		foreach ($this->tables as $table)
+		// Compose the FROM clause.
+		if (count($this->tables))
 		{
-			if ($table instanceof self)
+			$tables = $this->_arrangeTables($this->tables);
+			if ($tables !== '')
 			{
-				$subquery = $table->getQueryString($this->_prefix, $this->_args);
-				foreach ($table->getQueryParams() as $param)
-				{
-					$this->_params[] = $param;
-				}
-				$tables[] = (count($tables) ? ', ' : '') . sprintf('(%s) AS `%s`', $subquery, $table->alias);
-			}
-			else
-			{
-				$tabledef = self::quoteName($table->name) . ($table->alias ? (' AS `' . $table->alias . '`') : '');
-				if ($table->join_type)
-				{
-					$join_where = $this->_arrangeConditions($table->join_conditions);
-					if ($join_where !== '')
-					{
-						$tabledef = $tabledef . ' ON ' . $join_where;
-					}
-					$tables[] = ' ' . $table->join_type . ' ' . $tabledef;
-				}
-				else
-				{
-					$tables[] = (count($tables) ? ', ' : '') . $tabledef;
-				}
+				$result .= ' FROM ' . $tables;
 			}
 		}
-		$result .= ' FROM ' . implode('', $tables);
 		
 		// Compose the WHERE clause.
 		if (count($this->conditions))
@@ -245,6 +233,86 @@ class Query extends VariableBase
 		return $result;
 	}
 	
+	/**
+	 * Generate a INSERT query string.
+	 * 
+	 * @return string
+	 */
+	protected function _getInsertQueryString(): string
+	{
+		return '';
+	}
+	
+	/**
+	 * Generate a UPDATE query string.
+	 * 
+	 * @return string
+	 */
+	protected function _getUpdateQueryString(): string
+	{
+		return '';
+	}
+	
+	/**
+	 * Generate a DELETE query string.
+	 * 
+	 * @return string
+	 */
+	protected function _getDeleteQueryString(): string
+	{
+		return '';
+	}
+	
+	/**
+	 * Generate a FROM clause from a list of tables.
+	 * 
+	 * @param array $tables
+	 * @return string
+	 */
+	protected function _arrangeTables(array $tables): string
+	{
+		// Initialize the result.
+		$result = array();
+		
+		// Process each table definition.
+		foreach ($tables as $table)
+		{
+			// Subquery
+			if ($table instanceof self)
+			{
+				$tabledef = sprintf('(%s) AS `%s`', $table->getQueryString($this->_prefix, $this->_args), $table->alias);
+				foreach ($table->getQueryParams() as $param)
+				{
+					$this->_params[] = $param;
+				}
+			}
+			
+			// Simple table
+			else
+			{
+				$tabledef = self::quoteName($table->name) . ($table->alias ? (' AS `' . $table->alias . '`') : '');
+			}
+			
+			// Add join conditions
+			if ($table->join_type)
+			{
+				$join_where = $this->_arrangeConditions($table->join_conditions);
+				if ($join_where !== '')
+				{
+					$tabledef = $tabledef . ' ON ' . $join_where;
+				}
+				$result[] = ' ' . $table->join_type . ' ' . $tabledef;
+			}
+			else
+			{
+				$result[] = (count($result) ? ', ' : '') . $tabledef;
+			}
+		}
+		
+		// Combine the result and return as a string.
+		return implode('', $result);
+	}
+	
 	/**
 	 * Generate a WHERE clause from a list of conditions.
 	 * 
diff --git a/common/framework/parsers/dbquery/variablebase.php b/common/framework/parsers/dbquery/variablebase.php
index c63fb5f06..6dd93e609 100644
--- a/common/framework/parsers/dbquery/variablebase.php
+++ b/common/framework/parsers/dbquery/variablebase.php
@@ -214,6 +214,18 @@ class VariableBase
 				$conditions = implode(' AND ', $conditions);
 				$where = count($keywords) === 1 ? $conditions : "($conditions)";
 				break;
+			case 'plus':
+				$where = sprintf('%s = %s + %s', $column, $column, $is_expression ? $value : '?');
+				if (!$is_expression) $params[] = $value;
+				break;
+			case 'minus':
+				$where = sprintf('%s = %s - %s', $column, $column, $is_expression ? $value : '?');
+				if (!$is_expression) $params[] = $value;
+				break;
+			case 'multiply':
+				$where = sprintf('%s = %s * %s', $column, $column, $is_expression ? $value : '?');
+				if (!$is_expression) $params[] = $value;
+				break;
 			default:
 				$where = sprintf('%s = ?', $column);
 				$params[] = $value;
diff --git a/common/framework/parsers/dbqueryparser.php b/common/framework/parsers/dbqueryparser.php
index 7705c1224..a065a6875 100644
--- a/common/framework/parsers/dbqueryparser.php
+++ b/common/framework/parsers/dbqueryparser.php
@@ -57,25 +57,26 @@ class DBQueryParser
 		{
 			if (trim($tag['query']) === 'true')
 			{
-				$subquery = self::_parseQuery($tag);
-				$query->tables[$subquery->alias] = $subquery;
+				$table = self::_parseQuery($tag);
+				$query->tables[$table->alias] = $table;
 			}
 			else
 			{
 				$table = new DBQuery\Table;
 				$table->name = trim($tag['name']);
 				$table->alias = trim($tag['alias']) ?: $table->name;
-				$table_type = trim($tag['type']);
-				if (stripos($table_type, 'join') !== false)
-				{
-					$table->join_type = strtoupper($table_type);
-					if ($tag->conditions)
-					{
-						$table->join_conditions = self::_parseConditions($tag->conditions);
-					}
-				}
-				$query->tables[$table->alias] = $table;
 			}
+			
+			$table_type = trim($tag['type']);
+			if (stripos($table_type, 'join') !== false)
+			{
+				$table->join_type = strtoupper($table_type);
+				if ($tag->conditions)
+				{
+					$table->join_conditions = self::_parseConditions($tag->conditions);
+				}
+			}
+			$query->tables[$table->alias] = $table;
 		}
 		
 		// Load columns.
@@ -86,9 +87,9 @@ class DBQueryParser
 				$subquery = self::_parseQuery($tag, trim($tag['id']));
 				$query->columns[] = $subquery;
 			}
-			else
+			elseif ($query->type === 'SELECT')
 			{
-				$column = new DBQuery\Column;
+				$column = new DBQuery\ColumnRead;
 				$column->name = trim($tag['name']);
 				$column->alias = trim($tag['alias']) ?: null;
 				if ($column->name === '*' || preg_match('/\.\*$/', $column->name))
@@ -101,6 +102,19 @@ class DBQueryParser
 				}
 				$query->columns[] = $column;
 			}
+			else
+			{
+				$column = new DBQuery\ColumnWrite;
+				$column->name = trim($tag['name']);
+				$column->name = trim($tag['operation']) ?: 'equal';
+				$column->var = trim($tag['var']) ?: null;
+				$column->default = trim($tag['default']) ?: null;
+				$column->not_null = trim($tag['notnull'] ?: $tag['not-null']) !== '' ? true : false;
+				$column->filter = trim($tag['filter']) ?: null;
+				$column->minlength = intval(trim($tag['minlength']), 10);
+				$column->maxlength = intval(trim($tag['maxlength']), 10);
+				$query->columns[] = $column;
+			}
 		}
 		
 		// Load conditions.
@@ -153,7 +167,7 @@ class DBQueryParser
 		// If a SELECT query has no columns, use * by default.
 		if ($query->type === 'SELECT' && !count($query->columns))
 		{
-			$column = new DBQuery\Column;
+			$column = new DBQuery\ColumnRead;
 			$column->name = '*';
 			$column->is_wildcard = true;
 			$column->is_expression = true;