diff --git a/framework/db/dao/ColumnSchema.php b/framework/db/dao/ColumnSchema.php index 6fb34dcf4c..0ab2819bcf 100644 --- a/framework/db/dao/ColumnSchema.php +++ b/framework/db/dao/ColumnSchema.php @@ -19,7 +19,7 @@ namespace yii\db\dao; class ColumnSchema extends \yii\base\Component { /** - * The followings are supported abstract column data types. + * The followings are the supported abstract column data types. */ const TYPE_STRING = 'string'; const TYPE_TEXT = 'text'; diff --git a/framework/db/dao/QueryBuilder.php b/framework/db/dao/QueryBuilder.php index cf2598c171..abdd2ce335 100644 --- a/framework/db/dao/QueryBuilder.php +++ b/framework/db/dao/QueryBuilder.php @@ -34,7 +34,7 @@ class QueryBuilder extends \yii\base\Object */ public $connection; /** - * @var Driver the database driver + * @var Driver the database driver used for this query builder. */ public $driver; /** @@ -43,9 +43,10 @@ class QueryBuilder extends \yii\base\Object */ public $separator = " "; /** - * @var Query the Query object. This is set when calling [[build()]] to generate a non-SELECT SQL statement. + * @var Query the Query object that is currently processed by the query builder to generate a SQL statement. + * After the SQL statement is generated by [[build()]], this property will be set null. */ - private $_query; + public $query; /** * Constructor. @@ -66,33 +67,43 @@ class QueryBuilder extends \yii\base\Object */ public function build($query) { + $this->query = $query; if ($query->operation !== null) { // non-SELECT query - $this->_query = $query; $method = array_shift($query->operation); $sql = call_user_func_array(array($this, $method), $query->operation); - $this->_query = null; - return $sql; } else { // SELECT query $clauses = array( - $this->buildSelect($query), - $this->buildFrom($query), - $this->buildJoin($query), - $this->buildWhere($query), - $this->buildGroupBy($query), - $this->buildHaving($query), - $this->buildUnion($query), - $this->buildOrderBy($query), - $this->buildLimit($query), + $this->buildSelect(), + $this->buildFrom(), + $this->buildJoin(), + $this->buildWhere(), + $this->buildGroupBy(), + $this->buildHaving(), + $this->buildUnion(), + $this->buildOrderBy(), + $this->buildLimit(), ); - return implode($this->separator, array_filter($clauses)); + $sql = implode($this->separator, array_filter($clauses)); } + $this->query = null; + return $sql; } /** * Creates and executes an INSERT SQL statement. * The method will properly escape the column names, and bind the values to be inserted. + * For example, + * + * ~~~ + * $params = array(); + * $sql = $queryBuilder->insert('tbl_user', array( + * 'name' => 'Sam', + * 'age' => 30, + * ), $params); + * ~~~ + * * @param string $table the table that new rows will be inserted into. * @param array $columns the column data (name=>value) to be inserted into the table. * @param array $params the parameters to be bound to the query. This method will modify @@ -117,8 +128,8 @@ class QueryBuilder extends \yii\base\Object $count++; } } - if ($this->_query instanceof Query) { - $this->_query->addParams($params); + if ($this->query instanceof Query) { + $this->query->addParams($params); } return 'INSERT INTO ' . $this->driver->quoteTableName($table) @@ -129,6 +140,15 @@ class QueryBuilder extends \yii\base\Object /** * Creates and executes an UPDATE SQL statement. * The method will properly escape the column names and bind the values to be updated. + * For example, + * + * ~~~ + * $params = array(); + * $sql = $queryBuilder->update('tbl_user', array( + * 'status' => 1, + * ), 'age > 30', $params); + * ~~~ + * * @param string $table the table to be updated. * @param array $columns the column data (name=>value) to be updated. * @param mixed $condition the condition that will be put in the WHERE part. Please @@ -153,8 +173,8 @@ class QueryBuilder extends \yii\base\Object $count++; } } - if ($this->_query instanceof Query) { - $this->_query->addParams($params); + if ($this->query instanceof Query) { + $this->query->addParams($params); } $sql = 'UPDATE ' . $this->driver->quoteTableName($table) . ' SET ' . implode(', ', $lines); if (($where = $this->buildCondition($condition)) != '') { @@ -166,6 +186,12 @@ class QueryBuilder extends \yii\base\Object /** * Creates and executes a DELETE SQL statement. + * For example, + * + * ~~~ + * $sql = $queryBuilder->delete('tbl_user', 'status = 0'); + * ~~~ + * * @param string $table the table where the data will be deleted from. * @param mixed $condition the condition that will be put in the WHERE part. Please * refer to [[Query::where()]] on how to specify condition. @@ -191,6 +217,16 @@ class QueryBuilder extends \yii\base\Object * If a column is specified with definition only (e.g. 'PRIMARY KEY (name, type)'), it will be directly * inserted into the generated SQL. * + * For example, + * + * ~~~ + * $sql = $queryBuilder->createTable('tbl_user', array( + * 'id' => 'pk', + * 'name' => 'string', + * 'age' => 'integer', + * )); + * ~~~ + * * @param string $table the name of the table to be created. The name will be properly quoted by the method. * @param array $columns the columns (name=>definition) in the new table. * @param string $options additional SQL fragment that will be appended to the generated SQL. @@ -201,7 +237,7 @@ class QueryBuilder extends \yii\base\Object $cols = array(); foreach ($columns as $name => $type) { if (is_string($name)) { - $cols[] = "\t" . $this->driver->quoteColumnName($name) . ' ' . $this->driver->getColumnType($type); + $cols[] = "\t" . $this->driver->quoteColumnName($name) . ' ' . $this->getColumnType($type); } else { $cols[] = "\t" . $type; @@ -213,13 +249,13 @@ class QueryBuilder extends \yii\base\Object /** * Builds a SQL statement for renaming a DB table. - * @param string $table the table to be renamed. The name will be properly quoted by the method. + * @param string $oldName the table to be renamed. The name will be properly quoted by the method. * @param string $newName the new table name. The name will be properly quoted by the method. * @return string the SQL statement for renaming a DB table. */ - public function renameTable($table, $newName) + public function renameTable($oldName, $newName) { - return 'RENAME TABLE ' . $this->driver->quoteTableName($table) . ' TO ' . $this->driver->quoteTableName($newName); + return 'RENAME TABLE ' . $this->driver->quoteTableName($oldName) . ' TO ' . $this->driver->quoteTableName($newName); } /** @@ -288,9 +324,10 @@ class QueryBuilder extends \yii\base\Object * Builds a SQL statement for changing the definition of a column. * @param string $table the table whose column is to be changed. The table name will be properly quoted by the method. * @param string $column the name of the column to be changed. The name will be properly quoted by the method. - * @param string $type the new column type. The [[getColumnType]] method will be invoked to convert abstract column type (if any) - * into the physical one. Anything that is not recognized as abstract type will be kept in the generated SQL. - * For example, 'string' will be turned into 'varchar(255)', while 'string not null' will become 'varchar(255) not null'. + * @param string $type the new column type. The [[getColumnType()]] method will be invoked to convert abstract + * column type (if any) into the physical one. Anything that is not recognized as abstract type will be kept + * in the generated SQL. For example, 'string' will be turned into 'varchar(255)', while 'string not null' + * will become 'varchar(255) not null'. * @return string the SQL statement for changing the definition of a column. */ public function alterColumn($table, $column, $type) @@ -306,20 +343,26 @@ class QueryBuilder extends \yii\base\Object * The method will properly quote the table and column names. * @param string $name the name of the foreign key constraint. * @param string $table the table that the foreign key constraint will be added to. - * @param string $columns the name of the column to that the constraint will be added on. If there are multiple columns, separate them with commas. + * @param string|array $columns the name of the column to that the constraint will be added on. + * If there are multiple columns, separate them with commas or use an array to represent them. * @param string $refTable the table that the foreign key references to. - * @param string $refColumns the name of the column that the foreign key references to. If there are multiple columns, separate them with commas. + * @param string|array $refColumns the name of the column that the foreign key references to. + * If there are multiple columns, separate them with commas or use an array to represent them. * @param string $delete the ON DELETE option. Most DBMS support these options: RESTRICT, CASCADE, NO ACTION, SET DEFAULT, SET NULL * @param string $update the ON UPDATE option. Most DBMS support these options: RESTRICT, CASCADE, NO ACTION, SET DEFAULT, SET NULL * @return string the SQL statement for adding a foreign key constraint to an existing table. */ public function addForeignKey($name, $table, $columns, $refTable, $refColumns, $delete = null, $update = null) { - $columns = preg_split('/\s*,\s*/', $columns, -1, PREG_SPLIT_NO_EMPTY); + if (!is_array($columns)) { + $columns = preg_split('/\s*,\s*/', $columns, -1, PREG_SPLIT_NO_EMPTY); + } foreach ($columns as $i => $col) { $columns[$i] = $this->driver->quoteColumnName($col); } - $refColumns = preg_split('/\s*,\s*/', $refColumns, -1, PREG_SPLIT_NO_EMPTY); + if (!is_array($refColumns)) { + $refColumns = preg_split('/\s*,\s*/', $refColumns, -1, PREG_SPLIT_NO_EMPTY); + } foreach ($refColumns as $i => $col) { $refColumns[$i] = $this->driver->quoteColumnName($col); } @@ -353,27 +396,27 @@ class QueryBuilder extends \yii\base\Object * Builds a SQL statement for creating a new index. * @param string $name the name of the index. The name will be properly quoted by the method. * @param string $table the table that the new index will be created for. The table name will be properly quoted by the method. - * @param string $column the column(s) that should be included in the index. If there are multiple columns, please separate them - * by commas. Each column name will be properly quoted by the method, unless a parenthesis is found in the name. + * @param string|array $columns the column(s) that should be included in the index. If there are multiple columns, + * separate them with commas or use an array to represent them. Each column name will be properly quoted + * by the method, unless a parenthesis is found in the name. * @param boolean $unique whether to add UNIQUE constraint on the created index. * @return string the SQL statement for creating a new index. */ - public function createIndex($name, $table, $column, $unique = false) + public function createIndex($name, $table, $columns, $unique = false) { - $cols = array(); - $columns = preg_split('/\s*,\s*/', $column, -1, PREG_SPLIT_NO_EMPTY); - foreach ($columns as $col) - { - if (strpos($col, '(') !== false) { - $cols[] = $col; - } else - { - $cols[] = $this->driver->quoteColumnName($col); + if (!is_array($columns)) { + $columns = preg_split('/\s*,\s*/', $columns, -1, PREG_SPLIT_NO_EMPTY); + } + foreach ($columns as $i => $column) { + if (strpos($column, '(') !== false) { + $columns[$i] = $column; + } else { + $columns[$i] = $this->driver->quoteColumnName($column); } } return ($unique ? 'CREATE UNIQUE INDEX ' : 'CREATE INDEX ') . $this->driver->quoteTableName($name) . ' ON ' - . $this->driver->quoteTableName($table) . ' (' . implode(', ', $cols) . ')'; + . $this->driver->quoteTableName($table) . ' (' . implode(', ', $columns) . ')'; } /** @@ -391,7 +434,7 @@ class QueryBuilder extends \yii\base\Object * Resets the sequence value of a table's primary key. * The sequence will be reset such that the primary key of the next new row inserted * will have the specified value or 1. - * @param CDbTableSchema $table the table schema whose primary key sequence will be reset + * @param string $table the table schema whose primary key sequence will be reset * @param mixed $value the value for the primary key of the next new row inserted. If this is not set, * the next new row's primary key will have a value 1. */ @@ -411,26 +454,30 @@ class QueryBuilder extends \yii\base\Object /** * Converts an abstract column type into a physical column type. * The conversion is done using the type map specified in [[typeMap]]. - * These abstract column types are supported (using MySQL as example to explain the corresponding + * The following abstract column types are supported (using MySQL as an example to explain the corresponding * physical types): - * + * + * - `pk`: an auto-incremental primary key type, will be converted into "int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY" + * - `string`: string type, will be converted into "varchar(255)" + * - `text`: a long string type, will be converted into "text" + * - `smallint`: a small integer type, will be converted into "smallint(6)" + * - `integer`: integer type, will be converted into "int(11)" + * - `bigint`: a big integer type, will be converted into "bigint(20)" + * - `boolean`: boolean type, will be converted into "tinyint(1)" + * - `float``: float number type, will be converted into "float" + * - `decimal`: decimal number type, will be converted into "decimal" + * - `datetime`: datetime type, will be converted into "datetime" + * - `timestamp`: timestamp type, will be converted into "timestamp" + * - `time`: time type, will be converted into "time" + * - `date`: date type, will be converted into "date" + * - `money`: money type, will be converted into "decimal(19,4)" + * - `binary`: binary data type, will be converted into "blob" * * If the abstract type contains two or more parts separated by spaces (e.g. "string NOT NULL"), then only - * the first part will be converted, and the rest of the parts will be appended to the conversion result. + * the first part will be converted, and the rest of the parts will be appended to the converted result. * For example, 'string NOT NULL' is converted to 'varchar(255) NOT NULL'. + * + * If a type cannot be found in [[typeMap]], it will be returned without any change. * @param string $type abstract column type * @return string physical column type. */ @@ -438,201 +485,20 @@ class QueryBuilder extends \yii\base\Object { if (isset($this->typeMap[$type])) { return $this->typeMap[$type]; - } elseif (($pos = strpos($type, ' ')) !== false) { - $t = substr($type, 0, $pos); - return (isset($this->typeMap[$t]) ? $this->typeMap[$t] : $t) . substr($type, $pos); - } else { - return $type; - } - } - - protected function buildSelect($query) - { - $select = $query->distinct ? 'SELECT DISTINCT' : 'SELECT'; - if ($query->selectOption != '') { - $select .= ' ' . $query->selectOption; - } - - $columns = $query->select; - if (empty($columns)) { - return $select . ' *'; - } - - if (is_string($columns)) { - if (strpos($columns, '(') !== false) { - return $select . ' ' . $columns; - } - $columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY); - } - - foreach ($columns as $i => $column) { - if (is_object($column)) { - $columns[$i] = (string)$column; - } elseif (strpos($column, '(') === false) { - if (preg_match('/^(.*?)(?i:\s+as\s+|\s+)([\w\-\.])$/', $column, $matches)) { - $columns[$i] = $this->connection->quoteColumnName($matches[1]) . ' AS ' . $this->driver->quoteSimpleColumnName($matches[2]); - } else { - $columns[$i] = $this->connection->quoteColumnName($column); - } + } elseif (preg_match('/^(\w+)\s+/', $type, $matches)) { + if (isset($this->typeMap[$matches[0]])) { + return preg_replace('/^\w+/', $this->typeMap[$matches[0]], $type); } } - - return $select . ' ' . implode(', ', $columns); + return $type; } - protected function buildFrom($query) - { - if (empty($query->from)) { - return ''; - } - - $tables = $query->from; - if (is_string($tables) && strpos($tables, '(') !== false) { - return 'FROM ' . $tables; - } - - if (!is_array($tables)) { - $tables = preg_split('/\s*,\s*/', trim($tables), -1, PREG_SPLIT_NO_EMPTY); - } - foreach ($tables as $i => $table) { - if (strpos($table, '(') === false) { - if (preg_match('/^(.*?)(?i:\s+as\s+|\s+)(.*)$/i', $table, $matches)) { // with alias - $tables[$i] = $this->connection->quoteTableName($matches[1]) . ' ' . $this->connection->quoteTableName($matches[2]); - } else { - $tables[$i] = $this->connection->quoteTableName($table); - } - } - } - - return 'FROM ' . implode(', ', $tables); - } - - protected function buildJoin($query) - { - $joins = $query->join; - if (empty($joins)) { - return ''; - } - if (is_string($joins)) { - return $joins; - } - - foreach ($joins as $i => $join) { - if (is_array($join)) { // join type, table name, on-condition - if (isset($join[0], $join[1])) { - $table = $join[1]; - if (strpos($table, '(') === false) { - if (preg_match('/^(.*?)(?i:\s+as\s+|\s+)(.*)$/', $table, $matches)) { // with alias - $table = $this->connection->quoteTableName($matches[1]) . ' ' . $this->connection->quoteTableName($matches[2]); - } else { - $table = $this->connection->quoteTableName($table); - } - } - $joins[$i] = strtoupper($join[0]) . ' ' . $table; - if (isset($join[2])) { // join condition - $joins[$i] .= ' ON ' . $this->buildCondition($join[2]); - } - } else { - throw new Exception('The join clause may be specified as an array of at least two elements.'); - } - } - } - - return implode("\n", $joins); - } - - protected function buildWhere($query) - { - $where = $this->buildCondition($query->where); - return empty($where) ? '' : 'WHERE ' . $where; - } - - protected function buildGroupBy($query) - { - $columns = $query->groupBy; - if (empty($columns)) { - return ''; - } - if (is_string($columns) && strpos($columns, '(') !== false) { - return 'GROUP BY ' . $columns; - } - - if (!is_array($columns)) { - $columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY); - } - foreach ($columns as $i => $column) { - if (is_object($column)) { - $columns[$i] = (string)$column; - } elseif (strpos($column, '(') === false) { - $columns[$i] = $this->connection->quoteColumnName($column); - } - } - return 'GROUP BY ' . implode(', ', $columns); - } - - protected function buildHaving($query) - { - $having = $this->buildCondition($query->having); - return empty($having) ? '' : 'HAVING ' . $having; - } - - protected function buildOrderBy($query) - { - $columns = $query->orderBy; - if (empty($columns)) { - return ''; - } - if (is_string($columns) && strpos($columns, '(') !== false) { - return 'ORDER BY ' . $columns; - } - - if (!is_array($columns)) { - $columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY); - } - foreach ($columns as $i => $column) { - if (is_object($column)) { - $columns[$i] = (string)$column; - } elseif (strpos($column, '(') === false) { - if (preg_match('/^(.*?)\s+(asc|desc)$/i', $column, $matches)) { - $columns[$i] = $this->connection->quoteColumnName($matches[1]) . ' ' . strtoupper($matches[2]); - } else { - $columns[$i] = $this->connection->quoteColumnName($column); - } - } - } - return 'ORDER BY ' . implode(', ', $columns); - } - - protected function buildLimit($query) - { - $sql = ''; - if ($query->limit !== null && $query->limit >= 0) { - $sql = 'LIMIT ' . (int)$query->limit; - } - if ($query->offset > 0) { - $sql .= ' OFFSET ' . (int)$query->offset; - } - return ltrim($sql); - } - - protected function buildUnion($query) - { - $unions = $query->union; - if (empty($unions)) { - return ''; - } - if (!is_array($unions)) { - $unions = array($unions); - } - foreach ($unions as $i => $union) { - if ($union instanceof Query) { - $unions[$i] = $union->getSql($this->connection); - } - } - return "UNION (\n" . implode("\n) UNION (\n", $unions) . "\n)"; - } - - protected function buildCondition($condition) + /** + * Generates a SQL condition from the given PHP representation. + * @param string|array $condition the PHP representation of the SQL condition + * @return string the generated SQL condition. + */ + public function buildCondition($condition) { if (!is_array($condition)) { return $condition; @@ -710,4 +576,217 @@ class QueryBuilder extends \yii\base\Object throw new Exception('Unknown operator: ' . $operator); } + + /** + * @return string the SELECT clause built from [[query]]. + */ + protected function buildSelect() + { + $select = $this->query->distinct ? 'SELECT DISTINCT' : 'SELECT'; + if ($this->query->selectOption != '') { + $select .= ' ' . $this->query->selectOption; + } + + $columns = $this->query->select; + if (empty($columns)) { + return $select . ' *'; + } + + if (is_string($columns)) { + if (strpos($columns, '(') !== false) { + return $select . ' ' . $columns; + } + $columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY); + } + + foreach ($columns as $i => $column) { + if (is_object($column)) { + $columns[$i] = (string)$column; + } elseif (strpos($column, '(') === false) { + if (preg_match('/^(.*?)(?i:\s+as\s+|\s+)([\w\-\.])$/', $column, $matches)) { + $columns[$i] = $this->connection->quoteColumnName($matches[1]) . ' AS ' . $this->driver->quoteSimpleColumnName($matches[2]); + } else { + $columns[$i] = $this->connection->quoteColumnName($column); + } + } + } + + return $select . ' ' . implode(', ', $columns); + } + + /** + * @return string the FROM clause built from [[query]]. + */ + protected function buildFrom() + { + if (empty($this->query->from)) { + return ''; + } + + $tables = $this->query->from; + if (is_string($tables) && strpos($tables, '(') !== false) { + return 'FROM ' . $tables; + } + + if (!is_array($tables)) { + $tables = preg_split('/\s*,\s*/', trim($tables), -1, PREG_SPLIT_NO_EMPTY); + } + foreach ($tables as $i => $table) { + if (strpos($table, '(') === false) { + if (preg_match('/^(.*?)(?i:\s+as\s+|\s+)(.*)$/i', $table, $matches)) { // with alias + $tables[$i] = $this->connection->quoteTableName($matches[1]) . ' ' . $this->connection->quoteTableName($matches[2]); + } else { + $tables[$i] = $this->connection->quoteTableName($table); + } + } + } + + return 'FROM ' . implode(', ', $tables); + } + + /** + * @return string the JOIN clause built from [[query]]. + */ + protected function buildJoin() + { + $joins = $this->query->join; + if (empty($joins)) { + return ''; + } + if (is_string($joins)) { + return $joins; + } + + foreach ($joins as $i => $join) { + if (is_array($join)) { // join type, table name, on-condition + if (isset($join[0], $join[1])) { + $table = $join[1]; + if (strpos($table, '(') === false) { + if (preg_match('/^(.*?)(?i:\s+as\s+|\s+)(.*)$/', $table, $matches)) { // with alias + $table = $this->connection->quoteTableName($matches[1]) . ' ' . $this->connection->quoteTableName($matches[2]); + } else { + $table = $this->connection->quoteTableName($table); + } + } + $joins[$i] = strtoupper($join[0]) . ' ' . $table; + if (isset($join[2])) { // join condition + $joins[$i] .= ' ON ' . $this->buildCondition($join[2]); + } + } else { + throw new Exception('A join clause must be specified as an array of at least two elements.'); + } + } + } + + return implode("\n", $joins); + } + + /** + * @return string the WHERE clause built from [[query]]. + */ + protected function buildWhere() + { + $where = $this->buildCondition($this->query->where); + return empty($where) ? '' : 'WHERE ' . $where; + } + + /** + * @return string the GROUP BY clause built from [[query]]. + */ + protected function buildGroupBy() + { + $columns = $this->query->groupBy; + if (empty($columns)) { + return ''; + } + if (is_string($columns) && strpos($columns, '(') !== false) { + return 'GROUP BY ' . $columns; + } + + if (!is_array($columns)) { + $columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY); + } + foreach ($columns as $i => $column) { + if (is_object($column)) { + $columns[$i] = (string)$column; + } elseif (strpos($column, '(') === false) { + $columns[$i] = $this->connection->quoteColumnName($column); + } + } + return 'GROUP BY ' . implode(', ', $columns); + } + + /** + * @return string the HAVING clause built from [[query]]. + */ + protected function buildHaving() + { + $having = $this->buildCondition($this->query->having); + return empty($having) ? '' : 'HAVING ' . $having; + } + + /** + * @return string the ORDER BY clause built from [[query]]. + */ + protected function buildOrderBy() + { + $columns = $this->query->orderBy; + if (empty($columns)) { + return ''; + } + if (is_string($columns) && strpos($columns, '(') !== false) { + return 'ORDER BY ' . $columns; + } + + if (!is_array($columns)) { + $columns = preg_split('/\s*,\s*/', trim($columns), -1, PREG_SPLIT_NO_EMPTY); + } + foreach ($columns as $i => $column) { + if (is_object($column)) { + $columns[$i] = (string)$column; + } elseif (strpos($column, '(') === false) { + if (preg_match('/^(.*?)\s+(asc|desc)$/i', $column, $matches)) { + $columns[$i] = $this->connection->quoteColumnName($matches[1]) . ' ' . strtoupper($matches[2]); + } else { + $columns[$i] = $this->connection->quoteColumnName($column); + } + } + } + return 'ORDER BY ' . implode(', ', $columns); + } + + /** + * @return string the LIMIT and OFFSET clauses built from [[query]]. + */ + protected function buildLimit() + { + $sql = ''; + if ($this->query->limit !== null && $this->query->limit >= 0) { + $sql = 'LIMIT ' . (int)$this->query->limit; + } + if ($this->query->offset > 0) { + $sql .= ' OFFSET ' . (int)$this->query->offset; + } + return ltrim($sql); + } + + /** + * @return string the UNION clause built from [[query]]. + */ + protected function buildUnion() + { + $unions = $this->query->union; + if (empty($unions)) { + return ''; + } + if (!is_array($unions)) { + $unions = array($unions); + } + foreach ($unions as $i => $union) { + if ($union instanceof Query) { + $unions[$i] = $union->getSql($this->connection); + } + } + return "UNION (\n" . implode("\n) UNION (\n", $unions) . "\n)"; + } }